[From the U.S. Government Printing Office, www.gpo.gov]

                                                         -1,:3 / <-,- z

                   ENVIRONMENTAL GUIDELINES FOR SITE SELECTION,

               OPERATIONS AND MONITORING OF OFFSHORE AQUACULTURE IN


                            MISSISSIPPI COASTAL WATERS


                                   Prepared for

             Mississippi Department of Wildlife, Fisheries and Parks
                            Bureau of Marine Resources



                                   FINAL REPORT


                               Grant No. CZM817/7.3



























                                        by

                                   Jurij Homziak
                       Coastal Research and Extension Center
             Mississippi Agricultural and Forestry Experiment Station
                           Mississippi State University
                            2710 Beach Blvd., Suite 1-E
                                 Biloxi, MS 39531




         35
         SH


         .M7
         H6
         1991










                   ENVIRONMENTAL GUIDELINES FOR SITE SELECTION,

               OPERATIONS AND MONITORING OF OFFSHORE AQUACULTURE IN


                            MISSISSIPPI COASTAL WATERS


                                   Prepared for

             Mississippi Department of Wildlife, Fisheries and Parks
                            Bureau of Marine Resources



                                   FINAL REPORT


                               Grant No. CZM817/7.3












                                          U . S - DEPARTMENT OF COMMERCE NOAA
                                          COASTAL SERVICES CENTER
                                          2234 SOUTH HOBSON AVENUE
                                          CHARLESTON , SC 29405-24 13







                                        by

                                  Jurij Homziak
                      Coastal Research and Extension Center
             Mississippi Agricultural and Forestry Experiment Station
                           Mississippi State University
                           2710 Beach Blvd., Suite 1-E
                                Biloxi, MS 39531












                                     Abstract




             The major potential impacts of offshore aquaculture and

        actions to quantify, regulate and minimize these impacts have

        been identified in a variety of state and national studies. The

        main findings of these studies are:

             1. Solid wastes from both net pen and shellfish aquaculture

        operations will settle to the bottom and affect the benthic

        community immediately beneath the site. Selecting sites deep

        enough and with sufficient currents to disperse these wastes will

        minimize the impact.

             2. Important marine habitats, fisheries resources, public

        lands and endangered or threatened species can be affected by

        aquaculture operations. Determining appropriate separation

        distances and selecting sites away from sensitive or important

        habitats and public lands will minimize this impact. Impacts on

        piscivorous birds can be fu rther minimized by use of predator

        control netting and other non-lethal control measures. Control

        of avian predators must conform with existing federal guidelines.

             3. Nutrients released from net pens, especially nitrogen,

        can contribute to phytoplankton production in stratified,

        nutrient poor waters. Siting to avoid areas where nutrient

        depletion occurs and placing limits on total fish production in

        such areas can prevent adverse environmental effects.

             4. Fish culture in warm water conditions can place heavy

        demands on available dissolved oxygen levels. Selecting sites









         deep enough and with adequate current speeds to allow for

         adequate dispersion of wastes, setting appropriate limits on

         total fish production and following low waste feeding practices

         (dry, floating feeds, high digestibility, no fines) will minimize

         adverse impacts. The use of automatic feeders should be closely

         watched. The proportion of wasted feed is significantly greater

         with automatic feeders (overfeeding, fines) than with other

         feeding methods (Weston 1991a).

              5. The effect of aquaculture operations on water movement,

         quality and on the benthic environment are not detectable within

         tens of meters of the culture site. Major effects on benthic

         biota, reduction in dissolved oxygen and increased dissolved

         nutrient concentrations are limited to within a few meters of the


         culture site.


              6. There is no good evidence for net pens having an adverse

         impact on fish and other nektonic species, transmitting diseases

         to wild fish, contaminating resident fauna with antibiotics or in

         contributing to the development of antibiotic resistant microbial

         populations threatening to human health.

              7. The environmental effects of on- and off- bottom

         shellfish culture are generally limited to those associated with

         sediment deposition.

              Proper siting of net pens can assure the dispersion of both

         solid and dissolved wastes and the protection of sensitive areas.

              The severity of the environmental effects of net pen and

         shellfish raft culture are related to the size of the operation.


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         Site characterization surveys and operations and monitoring

         guidelines must be related to the size/production level of the

         facilities, with increasingly extensive requirements for larger

         facilities.


             Because long term data on currents and water quality

         conditions in the shallow, near shore waters of the northern Gulf

         of Mexico are so poor, permit requests for offshore aquaculture

         must be reviewed and evaluated on a case by case basis. Should a

         permit request be denied because the proposed operation does not

         satisfy recommended site selection, evaluation, operations and

         monitoring guidelines presented here, the burden of proof that

         there will be no significant environmental effect associated with

         the operation should fall on the applicant.

         I. INTRODUCTION


             Many of the fish and shellfish species upon which the Gulf

         seafood industry depends, such as redfish and oysters, have shown

         dramatic declines in abundance. Similar declines in other areas

         have affected the harvest of valuable species such as the striped

         bass. As catches have declined, demand and prices have risen.

         New techniques for farming fish and shellfish have been developed

         to meet growing demand. Cultured fish and shellfish have

         experienced rapid growth in Mississippi, in other parts of the

         U.S. and in other countries.


             Aside from pond culture, one of the most successful

         approaches to fin fish farming has been net pen culture, where

         fish are grown in pens or cages moored in open water. oyster


                                         3









         culture in mesh bags on the bottom or suspended from floating

         long lines has also met with success.

               The development of these techniques and the apparent

         profitability of commercial net pen and suspended shellfish

         aquaculture elsewhere has created a growing interest in the

         establishment of such facilities in Gulf of Mexico waters.

         Interest has also been spurred by some local developments. An

         on-bottom bag culture system for oysters was developed and tested

         in the Florida panhandle; a local aquaculturist is evaluating the

         feasibility of such a system in Mississippi waters. A net pen

         system moored to an offshore oil platform in 200 feet of water is

         being evaluated for fin fish culture off the Texas coast.

               The rapid growth of offshore aquaculture industries (defined

         as fin fish net pen culture and the cultivation of mollusks in

         floati ng or on-bottom structures) in other regions has brought

         attention-to the potential environmental effects of open water

         aquaculture. Regulatory agencies in these areas have examined

         these issues an d have developed siting, operations and monitoring

         guidelines to measure and limit the potential negative

         environmental effects of open water aquaculture. Through an

         analysis of these regulations, associated reports and the related

         scientific literature, this report attempts to identify the

         potential environmental effects of off shore aquaculture, to

         evaluate the importance of these effects in the northern Gulf of

         Mexico, and to provide guidelines for the siting, operation and

         monitoring of such operations. These guidelines are intended to


                                           4









        aid both the industry, by identifying criteria for selecting

        appropriate sites and scales of operation, and the regulatory

        agencies, by creating a framework for the permit review process.




        II. OPERATIONS


             Commercial net pen culture of fin fish in the marine/coastal

        waters of North America focuses on various species of salmon or

        steelhead trout culture. Other fin fish species are also

        cultured in cages, such as yellowtail in Japan and red sea bream

        in Taiwan and the Mediterranean region. Research is underway in

        Europe exploring the feasibility of raising cod, turbot and other

        species in cages.

             Because of recent advances in production technology, the

        most likely fin fish candidates for warm water marine net pen

        aquaculture in the U.S. are redfish and hybrid striped bass.

        This review will focus on conditions associated with the

        potential cultivation of these two species in Gulf waters.

        Net pen culture

             A brief description of commercial salmon operations (from

        Weston 1986a) will serve to introduce the technology used in net

        pen operations. In Washington, fish are held in net enclosures

        with 10 - 30 mm mesh, depending on the size of the fish. The

        dimensions of the enclosure vary among facilities. A small net

        pen may be only a few meters on a side, while larger net pens may

        measure 12 x 12 m. Net pens usually extend 2 - 4 in below the

        surface. At most facilities, net pens are moored together to


                                        5









          form a single large farm unit, with individual pens separated by

          walkways (Fig. 1). Buildings for shelter, equipment and feed

          storage and/or processing may be incorporated as well.

               Fingerlings are stocked into the pens in the spring of each

          year, but usually spread over several months to insure a steady

          supply of product. Stocking density of salmon depends on several
          factors but is usually 15 kg/m3.  "Pan-sized" fish (0.3 kg) are

          held for 6 - 11 months while market fish are held for 18 - 24

          months, until they reach 2 - 5 kg size.

               Salmon can be fed a variety of diets, including dry, moist

          and wet (minced fish) feeds. U.S. growers use dry feeds almost

          exclusively. Feed may be delivered by hand, by demand feeders or

          by automatic feeders. Salmon are usually fed 2% of body weight

          per day. This varies greatly with fish size, water temperature

          and other factors. Feed conversion ratios of 1.5 - 2:1


          (feed:fish weight) are commonly achieved.

               Proper husbandry practices (esp. stocking density),

          vaccination or addition of medicated feeds minimized loss to


          stress and disease mortality. Use of overhead netting,

          especially over pens holding smaller fish, excludes bird

          predators. Predation by fish and aquatic animals is prevented by

          use of a large mesh outer net around the facility. Nonlethal

          fish and marine mammal deterrents (e.g. acoustic devices) are

          also used.









                                          6











        Shellfish culture


             Two approaches are used to grow oysters in containers (Field

        and Drinnan 1988). "Off bottom" culture refers to methods used

        to grow oysters by suspending them from surface floats. In "on

        bottom" culture, oysters are grown in or on structures placed

        directly on the bottom. In both approaches, seed oysters from

        wild or hatchery sources are used.

             The distinguishing feature of off-bottom culture is the

        floatation system. Two basic types are used (see Magoon and

        Vining 1981, Nosho 1989): long lines and rafts. A long line

        consists of a 50 - 300 m long, 12 - 25 mm thick rope which is

        buoyed at 10 m intervals or less along its length, and well

        anchored at both ends. Strings or structures holding the oysters

        (usually nets or mesh bags) are suspended from the long line.

        Because of their inherent flexibility, long lines are more suited

        to open water situations. Rafts, on the other hand, have a rigid

        structure and are more suitable for sheltered locations. The

        most common raft type is of beams and crossbars bolted together

        and mounted on-a series of floats. Rafts are used for tray

        culture, where the oysters are held in mesh trays suspended from

        the rafts.

             The most common on-bottom systems use either mesh bags,

        linked into belts, or rigid stacks of cages, both of which are

        anchored to the bottom (Magoon and Vining 1981, Nosho 1989). The

        "flexible belt" method (Cresswell et al 1990) appears to be the

        more economically promising approach in Gulf waters. Regardless


                                         7









         of the approach, seed oysters are initially placed into small

         mesh trays or bags. The oysters are periodically moved to larger

         mesh containers as they grow, and the containers are regularly

         cleaned of fouling organisms.

         III. POTENTIAL ENVIRONMENTAL   EFFECTS


         1. Water Circulation Effects


              a) Water Circulation Effects Within the Structure

         Empirical studies of net pens on water circulation indicate

         substantial reduction of current velocities inside net pens

         (Inoue 1972). For pens 3 x 3 x 3 m with 2.4 cm mesh no fouling

         and no fish, it was estimated that current velocities would be

         reduced to 70 - 80t of initial velocity after passage through the

         first pen, and to 10 - 25% of initial velocity of after passage

         through 3 pens. Stocking density of fish, mesh size, pen volume,

         fouling and other variables can dramatically increase the

         resistance of the net pen to water flow (Weston 1986a). Water

         flow within shellfish rafts was measured at 12 - 14% of outside

         current velocity (Arakawa et al 1971). At a depth of 1 m below

         the culture strings no consistent current effects were evident.

              b) Water Circulation Effects Outside the Structure

              While any object placed within a current will alter water

         circulation,'there have been no measurements of the effects of

         net pens or mollusk culture structures on water circulation.

         Based on the estimated effects of solid structures on water flow,

         Weston (1986a) estimated porous-structures such as net pens or

         shellfish rafts will reduce current velocity upstream for a


                                         8









        distance about equal to the dimension of the net pen

        perpendicular to the current flow. Current velocity at the sides

        of the structure was estimated to be 95% of the free stream value


        at a distance of about two structure diameters. Downstream

        current velocity was estimated to return to 95% of the free

        stream value within 20 structure diameters.


             While Weston (1986a) provided no estimate on the vertical

        extent of current velocity reduction by floating aquaculture

        structures, the effect should be detectable at least to a depth

        of two structure heights. Where cages are moored in water just

        exceeding this depth, additional turbulence and boundary effects

        of the bottom on current flow will have to be considered in


        estimating reductions in current velocity and potential

        sedimentation effects.


             These figures are only order-of-magnitude approximations

        since variables such as mesh size, extent of fouling and current

        variation will affect the calculations significantly. Fouling of

        the net mesh or use of smaller diameter mesh will significantly

        increase the distances where currents are reduced.

             c) Sedimentation

             The reduction of current velocity in the vicinity of the

        aquaculture structures will cause suspended particles to settle

        out, increasing sediment deposition below net pens or rafts. As

        discussed here, sedimentation is distinct from sedimentation of

        waste material from the culture operation. This effect may

        especially significant for on-bottom shellfish culture


                                         9









          structures, and for floating net pens or shellfish rafts moored

          in shallow water. If such structures are located close enough to

          the bottom to restrict water flow, deposition of the suspended

          sediments and trapping of solid wastes from the net pens will

          probably occur. The problem may be magnified in areas of high

          suspended sediment loads.

               d) Circulation and water quality

               The reduction of current velocity within and outside the

          culture units may affect water quality by preventing an adequate

          supply of oxygenated water on inhibiting the removal of waste

          material. For shellfish culture, reduced current velocities

          within the structures may also reduce the quantity of food

          reaching interior or downstream shellfish, causing poor growth or

          mortality (Incze and Lutz 1980).

               Inoue (1972) estimated that current velocity in net pens

          will be one-half of the upstream velocity. To estimate current

          velocity through pens on a model salmon farm, Weston (1986a)

          incorporated the tidal variation in current velocity with net pen

          effects to derive an estimated average current flow into net pens

          of 20 - 40% of the peak ebb current velocity.

               Operations located in areas of low current velocity (less

          than 5 cm/sec) will have to take measures to minimize the effects

          of the structure on water circulation. Multiple net pens should

          be arranged perpendicular to current flow with an optimal spacing

          between pens or rafts of two diameters or more. This arrangement

          will minimize the effect of each unit on water circulation and



                                          10









         water quality. Water depth below the lowest point of the

         structure should exceed two times pen height.

         2. Water Quality

             a) Waste Inputs

             Waste inputs from net pen aquaculture are unutilized feed

         and the metabolic products of food breakdown (Weston 1986a,

         1986b, 1991a, 1991b, Weston and Gowan 1988). The inputs are:

         Ammonia - the principal nitrogenous excretory product of fish and

         shellfish. Can be present in ionized (NH4+) or unionized (NH3)

         form. At the temperature range (15 - 30 OC) and Ph (about 8.0)of

         Mississippi coastal waters, the percent of toxic unionized

         ammonia will be 1.5 - 4.0%.

         Nitrate and Nitrite - produced by the microbial degradation of

         other nitrogenous compounds; elevated concentrations may be

         expected in the vicinity of net pen aquaculture due to bacterial

         oxidation of ammonia.


         Organic Nitrogen - urea is the principal component, produced as

         an end product of protein metabolism.

         Phosphate - excreted in urine and leached from waste food and

         feces.


         Oxygen - respiration by the cultured organisms and the

         consumption of oxygen by decomposition of waste material (the

         biochemical oxygen demand on BOD) lower dissolved oxygen (DO)

         levels.










              b) Waste Loading

              Little information is available on nutrient or BOD loading

          from marine net pen culture. Most of the information has been

          developed from studies of salmonid culture in cool, freshwater

          systems. Reviews of published data for intensive raceway systems

          (and marine net-pen systems (Weston 1986a) suggest that loadings

          are extremely variable depending on type of feed, quantity and

          frequency of feeding, temperature, fish size and proportion of

          suspended solids in the effluent stream. As a result, loading

          values from any one aquaculture operation cannot be used to

          accurately predict loading values from another.

              Waste loads for net pen aquaculture are difficult to

          estimate for warm water marine systems. Several values are

          commonly cited. Estimated loadings per kg of fish produced   per

          day (g/kg fish/day), based on salmonid data from Ackefors and

          Enell (1990), are a BOD of 0.90 g, 0.23 g total nitrogen and 0.03

          g total phosphorus. Weston (1991a) used these values to estimate

          warm water net pen aquaculture waste loads in Chesapeake Bay.

          Approximations of waste loads generated by net pen salmon farming

          in Puget Sound, valued on a g/kg fish/day basis, are: ammonia -

          0.3, nitrate 0.1, organic nitrogen - 0.04, total nitrogen - 0.6,

          phosphate -0.1, total phosphorus -0.1, BOD - 3.0 (Weston 1986a).

          Huguenin and Colt's (1989) estimated waste load values for cool

          and warm sea water systems closely match the values derived from

          fresh water and cool water culture systems.




                                         12











             These estimates of waste loads include both dissolved


        nutrients that enter the water directly and nutrients which reach

        the bottom as waste feed or feces. Most of the nitrogenous waste

        will be released in dissolved form, while in marine waters most

        of the phosphorous will be part of the particulate material

        (Weston 1991a, 1991b). Most of the BOD is associated with the

        particulate material.

             Waste loading from shellfish culture is based not on inputs

        of external feed but on concentration of phytoplankton from the

        water column (Incze and Lutz 1980). There is no addition of new

        nutrients into the system. Generalizing from studies of cultured

        mussels, about 40% of the nutrients removed by shellfish are

        released directly back into the water column, 30% falls to the

        bottom as particulate material and 30t are removed in the harvest

        (Ackefors and S6dergren 1985).

                  A frequent comparison contrasts waste loads from net

        pen operations with other nutrient discharges (e.g. Weston 1986a,

        1991a). These comparisons are misleading. The relatively high

        BOD associated with net pen culture reflects the efficiency of

        sludge treatment at sewage plants, not an inherently greater BOD

        of fish wastes in comparison to domestic sewage (Weston 1991a).

        Similarly, while BOD and nutrient loadings from net pen

        operations appear to be comparable to industrial or domestic

        effluents, the concentrations of these wastes are far lower

        (Weston 1986a). Inputs of nutrients from farm and urban and

        sewage treatment effluent runoff, channeled by river flow into


                                        13










          Mississippi coastal waters, is a much greater source of

          enrichment.


               c) Dissolved Oxygen

               Fish and shellfish culture can be expected to reduce the

          dissolved oxygen content of the water by two mechanisms:

          respiration of the organisms and the biochemical oxygen demand of

          the waste feed, feces and urine. Because oxygen consumption of

          fish will depend upon fish species, size, water temperature,

          swimming speed and other factors, it is impossible to determine

          the oxygen needs of a net pen operation with any degree of

          precision. This assessment is complicated further by the fact

          that existing oxygen consumption data for hybrid striped bass and

          redfish is very limited. The same limitations hold true for

          shellfish culture.


               Oxygen consumption rates of juvenile hybrid striped bass (20
          - 100 g) at 24 OC were estimated to be 200 - 260 mg 02/kg fish/hr

          at a swimming speed of 1 cm/sec, and 320 - 400 mg 02/kg f ish/hr
          at a swimming speed of 10 cm/sec (Kruger andbrocksen 1978).

          Respiration data for hybrid striped bass at higher temperatures

          are not available. Rosati (1990) suggests a rule of thumb

          approximation: a fish consumes 1/4 pound of oxygen for each

          pound of f eed (about 114 9 02/kg f eed). Colt and Tchobanogious

          (1981) provide a range of respiration rates, 6 - 40 kg 02/1000 kg

          fish/d, for various species of freshwater fish. While their

          synthesis does not provide any information on swimming speeds,

          they report 100 g rainbow trout held in 150C water consumed about


                                          14









         312 Mg 02/kg fish/hr while 100 g channel catfish consumed nearly

         three times as much oxygen, 812 mg 02/kg f ish/hr. Hybrid striped

         bass hold in 300C water would have an oxygen requirement close to

         the upper end of this range which no oxygen consumption data for

         redfish are available, limited observations of redfish juveniles

         indicates that their critical oxygen concentrations are unusually

         high for warm water fishes, suggesting an elevated oxygen

         consumption rate (Neill 1987).

              These dissolved oxygen consumption rates may effectively

         limit the size of net pen operations in Mississippi waters of the

         northern Gulf of Mexico. The solubility of oxygen at 25 ppt

         salinity and 28 OC is 6.8 mg/l, 7.3 mg/l at 24 OC (Colt 1980).

         Assuming the water exits the net pen at a dissolved oxygen
         concentration of 5 Mg 02/1 (the minimum culture requirement),
         this leaves 1.8 and 7.3  Mg 02/1 for fish respiration at 25 0 and

         24 *C, respectively.

              A load of 250, 000 kg of f ish, consuming 600 mg 02/kg/m, in a

         3 cm/sec current inside the cage would use about 0.6 mg 02/1 Of

         flow. Halving the current flow will double the oxygen

         consumption. As noted earlier, current velocities within cages

         are 20 - 40% of maximum ebb current velocities.

              Field investigations around net pens have reported decreases

         in dissolved oxygen. Dissolved oxygen concentrations 0.2 - 2.5

         Mg 02/1 less than ambient were observed around yellowtail and sea

         bream cages in Japan. There was no evident oxygen depletion

         beyond the immediate boundaries of the farm. This is an extreme


                                          15










         case where circulation was limited and a large quantity of fish

         (400 mt) were being held. In most cool water conditions, net pen

         aquaculture operations did not have any measurable effects on

         dissolved oxygen content.

            - Similarly, no evidence of dissolved oxygen depletion was

         noted around commercial scale suspended mussel operations in

         Sweden or New Zealand (see references in Weston 1986a).

         Suspended shellfish culture operations in the northern Gulf of

         Mexico are not expected to have significant effects on dissolved

         oxygen concentrations or on other water quality parameters.

              Oxygen consumption can be estimated for planned shellfish

         culture operations in the northern Gulf of Mexico. Average

         oxygen consumption rates for oysters have been reported to be 303

         Ml 02/kg of wt tissue/hr (Hammen 1969). The rate of oxygen

         consumption, however, increases as salinities decrease. Shumway

         (1982) describes this function. At 28 ppt salinity and a water

         temperature of 30 OC, the oxygen consumption rate is 200 ml 02/kg

         wet tissue/hr or 39 ml/kg/hr for whole oysters. Long line

         culture of mussels supports an additional 15% biomass of fouling

         organisms (Weston 1986a). While fouling biomass for Gulf oyster

         culture is not known, biomass estimates for oxygen consumption

         calculations should be adjusted upwards by at least this amount.

              d) Nitrogen and Phosphorus

              Because feed is not added, shellfish culture does not add

          new" nitrogen and phosphorous to the environment. Shellfish do,

         however, increase the rate at which these nutrients are recycled.


                                         16









         By ingesting phytoplankton and excreting a large part of their

         constituent nutrients, shellfish make dissolved nutrients more

         readily available for use by other organisms. The potential for

         this increased nutrient cycling to stimulate phytoplankton blooms

         has been noted (Tenore and Gonzales 1975) but field studies have

         failed to find any effect of shellfish culture on phytoplankton

         productivity (Weston 1986a, 1986b).

             Feeds are the main source of waste nutrients in net.pen

         culture. Ammonia and, to a lesser extent, urea, are the

         principal nitrogenous wastes associated with net pen culture.

         Ammonia can be present as the non-toxic ammonium ion (NH4* or as

         the toxic unionized form (NH3). At the temperatures and pH of

         marine waters in the northern Gulf of Mexico, 0.2 - 5% of ammonia

         will be in the toxic form (Huguenin and Colt 1989). At these

         levels ammonia toxicity is not likely to be a problem.

             Phosphorus is also introduced with feeds. In marine systems

         only limited amounts enter into the environment through urine.

         Leaching from waste feed and feces is an important source of

         dissolved phosphorous.

             The form of nitrogen and phosphorus input and their

         potential impacts are very different. Nitrogen is released

         largely in the soluble form, while phosphorus in sea water is

         associated primarily with feed and feces. The phosphorus

         initially deposited in the sediments can later be released into

         the water column, particularly under anaerobic conditions (Weston

         1991a, 1991b).


                                        17











              Localized increases in nutrient concentrations have been

         reported in the immediate vicinity of net pen culture sites.

         Such observations are common and should be expected. The extent

         of measurable enrichment will depend upon hydrographic factors,

         but dilution is generally very rapid and nutrient increases have

         been limited to within tens of meters of the net pens.

              The primary concern associated with dissolved nutrient input

         is the effect it may have on phytoplankton production. Tagaki et

         al. (1980) and Arakawa et al (1973, cited in Weston 1986a)

         related phytoplankton blooms to oyster culture and Nishimura

         (1982, cited in Weston 1986a) to fin fish culture in Japan. This

         may be of particular importance where potentially toxic

         phytoplankton species are involved. The neurotoxin-producing

         diatom, Nitzschia pungens f. multiseries, has been identified

         from the northern Gulf (Fryxell et al 1991). A related form has

         been implicated in shellfish poisoning in Canada. Other toxic

         algal blooms involving Ptychodiscus brevis and Gonyaulax monilata

         have been reported from the Florida and Texas (Snider 1987).

              It is important to remember that while nutrient discharges

         have been implicated as potentially contributing factors in

         phytoplankton blooms, this input alone will not cause a bloom.

         Many environmental factors must interact to provide the

         conditions suitable for rapid phytoplankton growth.

         Phytoplankton population.also require several days to increase to

         bloom proportions, while dilution and water movement mix the

         nutrient rich effluent with the surrounding water on a  scale of


                                         18










         meters and hours. Only in static systems have studies shown a

         measurable effect of net pen culture on productivity (see

         references in Weston 1986a).

             It is only in areas with reduced nitrogen concentrations

         that the additional input of nutrients may have a measurable

         effect on productivity. Areas with a high degree of vertical

         stratification because of fresh water inflow or minimal tidal


         mixing would be particularly susceptible to nitrogen depletion in

         surface waters. Japanese researchers have suggested nitrogen

         concentrations of 0.35 mg/l (Takagi et al 1980), and 0.1 mg/l

         (Iwasaki 1976, cited in Tagaki et al 1980), the limit proposed by

         Weston (1986a, 1986b), to identify nitrogen depleted areas

         susceptible to phytoplankton blooms. Stratification of the

         waters south of the Mississippi barrier islands is frequent

         (Kjerfve and Sneed 1984), and surface waters depleted of nitrogen

         are common under these conditions. Studies by USEPA (19901 in

         the area have revealed total nitrogen concentrations below 0.1

         mg/l.

              In areas where nutrients are limiting to phytoplankton

         growth, any input would, by definition, stimulate production.

         However, in most areas dilution by a current action and surface

         mixing would minimize any potential localized effects on

         productivity. Siting culture operations away from nutrient

         depleted, stratified waters, following correct feeding
         procedures, feeding only dry pellets, eliminating fines, reducing



                                        19










          waste and using highly digestible feeds will all contribute to

          reducing waste impacts on water quality.

          3. Benthic effects.


               a) Solid Waste Production

               Excess feed, fecal material and debris from structures are

          the main solid wastes associated wit h offshore aquaculture.

               The amount of wasted feed (that which passes through the

          cages) is highly variable, depending upon culture practices such

          as feed type used (dry, moist, wet), feeding methods (hand,

          automatic, demand) and frequency of feeding. Estimates of waste

          feed for net pen operations in Maine (Maine Department of Marine

          Resources 1991) and Washington (Weston 1986a) are about 5%, but

          can be as high as 20%.

               Fecal production is the second major source of solid waste,

          While fecal production rates for net pen culture are not

          available, trout fed dry pelleted feed under laboratory.

          conditions lost 25 - 38% as feces on a dry weight basis (Butz and

          Vens-Capell 1982). Weston (1986a) assumed about one-third of the

          feed ingested was lost as feces in commercial net pen culture in

          Washington.

               Assuming a dry feed is used and a feed conversion ratio of

          2:1, the production of 1 kg of fish will result in an estimated

          production of 0.7 kg (dry weight) of solid waste, using Weston's

          (1986a) assumption. Of the two kg of feed fed, approximately 5%

          (0.1 kg) is wasted. The remainder, 1.9 kg, is ingested by the

          fish. About one-third or 0.6 kg is lost as feces. This is a


                                          20









         best case situation with a minimal amount (5%) of feed wastage.

         Using these assumptions, a large facility producing 250 metric

         tons of fish per year is estimated to produce about 175 metric

         tons of solid waste per year (Weston 1986a).

             In warm water areas, such as the Gulf of Mexico, the

         sloughing off of fouling organism from net pen and shellfish

         culture structures may also be a significant solid waste input.

         The contribution of fouling organisms to the solid waste stream

         is not known but is expected to be significant in warm water

         ,ituations where fouling may be severe.

             The Institute of Aquaculture (1988, cited in Weston 1991a)

         estimated solid waste production of 520 kg per metric ton of

         fish, assuming 20% feed wastage and 30% feces loss. This may be

         a more accurate estimate of solid wastes.

             Solid waste production rates are very sensitive to changes

         in feed conversion ratios (FCR) and feed wastage. Reducing FCR

         from 2:1 to 1.5:1 would reduce sediment production by about 25%.

             Shellfish culture also produces solid waste in the form of

         feces and pseudofeces, shells lost from the structure and fouling

         organisms sloughed off during cleaning. Arakawa et al (1971) and

         Kusuki (1977) estimated that a single raft holding 350,000 -
         630,000 oysters can produce 16 metric tons (dry weight) of feces

         and pseudofeces and an additional 4.5 tons of feces from fouling

         organisms in a nine month growing season.






                                        21










               b) Sedimentation

               Sedimentation rates have been estimated for a variety of

          culture situations using net pens and floating rafts (see review

          in Weston 1986a). Much of the data, based on sediment trap

          results, is of questionable value because of re-suspension and

          artifacts related to trap size and shape. The data are useful,

          however, in obtaining estimates of sedimentation beneath net

          pens/rafts relative to a reference area with a similar current

          regime. Sedimentation rates beneath net pens have been found to

          be 2 - 10 times greater than in reference areas (Pease 1977,

          Weston and Gowan 1988).

               Rates of deposition beneath mussel long lines have been

          reported to be 2 - 4 times greater than surrounding areas

          (DahlbAck and Gunnarsson 1981). Arakawa et al (1971) reported

          that approximately 20 - 30t of the 20 tons of solid waste were

          generated by an oyster raft and deposited in the vicinity of the

          raft.


               Placement of net pens or rafts in shallow water will

          significantly increase rates of sediment deposition by lowering

          current velocity beneath the structures. Water depth beneath the

          bottom of the net pens should be at least two structure heights-

          to eliminate the effects of current reduction. Results from an


          analysis by Weston (1986a, 1986b) suggest that sediment

          accumulation is likely if net pens are located where water depths

          under the pens are less than 15 m. Braaten et al (1983) suggests

          a clearance of at least 10 m beneath net pens and further


                                         22









         suggests sites with strong currents. Washington State has

         adopted the recommendations of Weston (1986a), using the size of

         an operation to determine minimum acceptable water depths and

         current speeds for siting a net pen operation (Washington

         Department of Fisheries 1990). British Columbia requires  a

         minimum of 6 m of water depth below the bottom of net pens, New

         Zealand 7.5 m (see references in Weston 1991a, 1991b). While

         Maine has no rigid depth requirements for sites, they consider

         the Washington guidelines and local site conditions in previewing

         permit applications (Maine Department of Marine Resources 1991).

              c) Effects on Sediment Chemistry

             Under hydrological conditions typical of the northern Gulf

         of Mexico, much of the fecal matter, waste feed and debris will

         settle in the immediate vicinity of the net pens or shellfish

         rafts. The area receiving solid wastes from fish culture net

         pens will be visibly affected and are described in a number of

         sources (e.g4 Weston 1986a, 1986b, 1991a, Washington Department

         of Fisheries 1990) Aside from the presence of food pellets, the

         area beneath shellfish culture rafts are similar in appearance

         (Dahlb9ck and Gunnarsson 1981). Food pellets will be readily

         detectible and the feces may form a flocculent deposit 5 cm or

         more in thickness. Sediment color changes to anoxic black in

         highly enriched conditions, or to shades of red or orange if only

         moderately enriched. A common indicator of enrichment is the

         presence of the filamentous, sulphide-reducing bacteria,

         Begglatoa, found in dense whitish mats on the sediment surface.


                                        23










               The area affected by solid waste from the aquaculture

          facility has been reported to be relatively small. Visible

          accumulations of solid waste from net pen facilities have

          generally been reported to be within 30 m of the culture facility

          (Weston 1986b), while significant changes in sediment chemistry

          have generally been written 15 m (Pamatmat et al 1973, Weston

          1986b, 1991a, 1991b). Arakawa et al (1971) and others (Dahlback

          and Gunnarsson 1981, Mattsson and Linden 1983) report that the

          area affected by sedimentation from shellfish culture does not

          extend more than about 20 m.


               The fate of solid wastes produced by a culture facility

          depends, in part, on the current velocity, water depth and

          sinking speed of the particles. Dispersion of waste particles

          increased with increasing depth and current velocity and with

          decreased sinking speeds.

               Solid wastes provide a source of labile carbon and nitrogen.

          It is the re-mineralization of carbon that produces the changes

          in sediment geochemistry typical of organic enrichment Weston

          1986a, 1991b). Sediment organic carbon inputs are an important

          measure of the impacts of fish farms on the marine environment.

          These can be measured by changes in benthic oxygen consumption,

          reduction-oxidation (redox) potential, total organic carbon,

          total volatile solids, sulfide concentrations and levels of

          nitrogenous and phosphorus compounds.

               In general, only about 20% of the carbon supplied to the

          farmed fish in feed is removed with the harvest. The 80%



                                          24









         remaining is lost, with a seasonally variable amount (30 - 70%)

         accumulating in the sediments in the short term (Hall et al

         1990). Over the long term, the sediment serves as a sink for

         about 18% of the total carbon input (Weston 1991a).

             Re-mineralization of carbon rich sediments consumes

         substantial amounts of oxygen. The biochemical oxygen demand

         (BOD) of fish feces and other metabolic wastes may consume 1.5 -

         3 times as much oxygen as respiration (Liao and Mayo 1974).

         Rosati (1990) provides a rule of thumb estimate of 750 g of BOD

         oxygen consumption for each kg feed used. Since most of the BOD

         is associated with solid waste, most of the oxygen required to

         meet this demand will be provided by bottom waters and sediment

         pore waters. Dahlbdck and Gunnarsson (1981) measured sediment

         oxygen demand beneath a mussel culture operation to be 1.4 1
         02/M2/day (at 15 OC and a sedimentation rate of 2.4-3.3 g organic
         C/m2/day).

              Rates of biochemical oxygen consumption beneath net pens

         were found to be between 2 - 3 times and six times greater than

         reference values in two Washington state studies (Pease 1977,

         Pamatmat et al 1973). Even higher rates have been reported

         elsewhere (Weston 1991a). Because organic enrichment was limited

         to the vicinity of both fish and shellfish culture operations,

         elevated oxygen consumption rates were not detectable away form

         the site (Pamatmat et al 1973).

              The depletion of pore water oxygen in the sediments results

         in a shallowing of the aerobic portion of the sediment column,


                                         25









          measurable by both sediment color changes and more negative

          reduction - oxidation (redox) potentials in the sediment

          (DahlbAck and Gunnarsson 1981, Weston and Gowen 1988, Weston

          1991b). In fine sediments, the aerobic layer may be very shallow

          and the addition of organically enriched sediments may increase

          oxygen demand to the point where bottom water dissolved oxygen is

          depleted. This may well be the case in Mississippi coastal

          waters where large areas of silty sediments occur.

              An important chemical effect of reduced sediment oxygen

          levels is the production of toxic hydrogen sulfide (DahlbAck and

          Gunnarsson 1981, Weston and Gowen 1988, Weston 1991b). In the

          absence of oxygen, the microbial degradation of organic matter in

          seawater is accompanied by the reduction of sulfate to hydrogen

          sulfide. Hydrogen sulfide production has been associated with

          both net pen (e.g. Weston and Gowen 1988, Weston 1991b). and

          suspended shellfish culture operations (Dahlbdck and Gunnarsson

          1981). Because hydrogen sulfide is toxic, it can be harmful to

          both the culture organisms and to resident farms. Fish farms in

          Japan and Europe, located in shallow, enclosed waters, have been

          forced to relocate because of hydrogen sulfide toxicity from

          accumulated wastes (Weston 1986a, 1991a).

               The redox potential measures sediment oxygen content,

          defining the depth of the boundary (redox potential discontinuity

          or RPD) between aerobic and anaerobic sediments. This gives a

          measure of relative enrichment of the sediments, and is the

          recommended method to measure enrichment impacts beneath fish


                                         26










         farms. It is effective, relatively inexpensive and can be used

         in field conditions (Weston and Gowen 1988). The drawback is

         that in fine sediments, the RPD is so close to the surface that

         it may not be readily measurable. Measurement of total organic

         carbon (TOC) and total volatile solids (TVS) can also be used to

         document organic enrichment beneath aquaculture facilities.

              d) Biological chan2es due to organic enrichment

              Azoic zones (zones devoid of any animals) are reported under

         most fish farms and under shellfish rafts. The affected areas

         are limited to those immediately below the farm (DahlbAck and

         Gunnarsson, Weston 1986a, 1991a, 1991b). Stewart (1984) and

         others (e.g. Weston and Gowen 1988) observed these conditions to

         extend to about 3 m (10 ft) from the farm perimeter. This zone is

         usually demarcated by a "halo" of dense Begglatoa mats, which

         covers and stabilizes the underlying sediments. in areas of poor

         water circulation, the water immediately above the substrate may

         become anoxic, precluding Beggiatoa growth. No live animals are

         present in this zone, gas bubbles (methane) are evident a nd redox

         potentials are severely depressed.

              Pearson and Rosenberg (1978) related general changes in the

         benthic communities as the result of increasing organic

         enrichment. Benthic communities are altered along a gradient of

         organic enrichment from the background community of unaffected

         environments in towards the fish or shellfish farm. It must be

         noted that the transitions from one zone to another occur along a

         continuum with no clear boundaries. Depending upon the amount of


                                         27










          organic material deposited and the existing benthic community,

          the more affected zones may or may not be present under any

          specific operation. Major alterations to benthic communities are

          generally limited to the area immediately beneath culture

          facilities and for short (<30m) distances away from the site.

          These are, re spectively, the "footprint" and "shadow" impact


          areas.


               A stable, diverse benthic community is comprised of filter

          and sediment feeding organisms and predators exists in

          undisturbed sediments. Many of these animals are large and live

          in the sediment. As organic matter is introduced into an

          undisturbed environment, it provides an additional source of

          nutrition for the benthic organisms. This additional organic

          matter benefits the existing filter and deposit feeders, and

          encourages colonization by additional species. Thus, both

          species diversity and biomass (total weight) of the benthic

          organisms increase, and the benthic community is enhanced.

          Pearson and Rosenberg (1978) refer to this as the "transition

          zone".


               As the level of organic input increases, the normal

          community changes as many species, especially filter feeders, are

          displaced. The sediments become progressively dominated by

          various opportunistic deposit feeders, which flourish under these

          conditions. The most notable deposit feeder is the small, common

          polychaete worm Capitella capItata, indicative of organic

          enrichment. Under these conditions, the abundance of these


                                         28









         opportunistic species can reach very high densities, to the

         exclusion of other species. Elimination of the larger, deeper

         borrowing animals further reduces the ability of oxygen to

         penetrate the sediments. Thus, while the number of organisms

         increases dramatically, the diversity of species declines.

              At higher rates of sedimentation, even the opportunists

         cannot survive. At this point, the anoxic layer reaches the

         sediment surface, depriving the animals of oxygen and exposing

         them to toxic H2S' In these sediments, the surface is black and

         devoid of any animals (azoic). Methane and toxic H2S are

         produced and escape as bubbles into the water. Gowen et al

         (1988) estimated that input of organic matter at rates greater
         than about 8 g carbon/M2 /day resulted in the production of

         methane and azoic conditions. This rate of input has been

         associated with large scale intensive fish (see reviews in Weston

         1986a, 1991a) and shellfish culture (Cabanas et al 1979, cited in

         Dahlb9ck and Gunnarsson 1981).

              Accumulation of organic material may cause the mortality of

         non-mobile macro-fauna. The area affected would be limited to

         the zone of organic enrichment in the immediate vicinity of the

         aquaculture site. Significant effects on fish or mobile

         microfauna are to be expected. Only where limited flushing leads

         to waste accumulation and hypoxia of the near bottom water or

         other deleterious changes in water quality. Where water quality

         is maintained, fish and mobile macrofauna are attracted to

         aquaculture sites (Weston 1986a), even to those where azoic zones


                                         29









          have been created. At low concentrations, H2S can affect fish

          health through gill damage and at higher concentrations be toxic

          to fish or shellfish in the farm above the sediments (Braaten et

          al 1983). Such effects have only been reported in stagnant areas

          with little water circulation.


               The extent of the effects of net pens or other aquaculture

          structures depends on the extent of alterations in sediment

          chemistry, itself a function of the degree of waste dispersal by

          water movements and depth, as well as culture practices (Weston

          1991a, 1991b). As the potential for waste dispersal increases

          with increasing depth and current speed, the possibility of

          significant impacts on the benthos decreases. Recovery of

          affected benthic communities may take months or years. However,

          the benthic sediment chemistry appears to'recover to normal

          levels relatively rapidly. In Puget Sound, Pamatmat et al (1973)

          observed normal benthic oxygen consumption 2 months after pen

          removal. Dixon (1986, cited in Washington Department of

          Fisheries 1990) noted that bottom sediments appeared normal at

          two pen sites in the Shetland Islands, 12 months after removal   of

          the farm.


               Biological recovery may take longer depending  on the

          successional colonization of the area by different  species  and

          normal recruitment cycles (Pearson and Rosenberg 1978). Species

          abundance will recover more quickly than biomass due to the

          growth rates of the larger animals. Gowan et al (1988) observed

          virtually no faunal recovery 8 months after cessation of net pen


                                          30









        operations. Mattsson and Linden (1983) found only limited

        recovery of the macrofaunal community 18 months after the removal

        of mussel long-lines.

             While the chemical and biological impacts of aquaculture

        operations on the benthos are readily described, they are not as

        readily predictable. Weston (1986a, 1991a, 1991b) concluded that

        the primary factors responsible for patterns of sediment

        enrichment were current velocity, water depth and loading (weight

        of fish held). Depth and current conditions in Mississippi

        waters are not be sufficient to completely avoid the effects of

        organic enrichment of offshore aquaculture on the benthic

        community. Recognizing this limitation, it is important that

        operations be located and designed so as to minimize the

        accumulation of solid wastes.

             Gowen et al (1988) and Weston and Gowan (1988) present a

        conceptually simple model of sediment deposition from a fish

        farm. The model has proven a good predictor of general sediment

        impacts at farm sites, despite inherent limitations. The model

        has the added ability to evaluate the effects of different pen

        sizes and configurations under different siting conditions,

        making it valuable for selecting suitable sites and designing

        farm capacity and layout.

             Minimizing feed wastage is especially important in reducing

        environmental impacts, reducing potential threats to the crop and

        improving operation economics. Gowan et al (1988) estimated that




                                        31









          reducing feed wastage from 30% to 5% would reduce the organic
          load to the benthos from 5.5 to 3.5 g carbon/M2 /d.

               Rotation of sites is sometimes practiced. This will not

          reduce benthic impacts significantly Weston 1991a, 1991b). The

          response of benthic communities to enrichment is rapid (weeks to

          months) while recovery is much slower (months to years). Unless

          the rotation is timed to allow complete recovery (an unlikely

          situation) it is not a useful means of minimizing environmental

          impact. Rotation and dredging to remove accumulated waste from

          beneath net pens may, however, provide some benefit to the

          cultured animals.

          4. Chemical usage.

               Fouling control and the treatment of diseases are essential

          for the maintenance of suitable culture conditions in net pen

          aquaculture. Chemicals used for these purposes pose a threat to

          the marine environment only when their potential for

          environmental damage is not fully known or the substances are

          misused.

               a) Anti-fouling compounds

               The best example of an anti-fouling chemical adversely

          affecting the marine environment is tributyltin (TBT). Treatment

          of boat hulls and nets with TBT has proven to be toxic to marine

          life in the parts per trillion range. The compound has been

          banned from use in many areas.

               The use of anti-foulant chemicals is probably unavoidable,

          given the rapid rate of fouling development in warm waters. Any


                                         32









        restriction of water movement through the nets by fouling could

        have profound effects on water quality within the net pens,

        potentially threatening the health of the crop. At the same

        time, the cost of labor involved in frequent cleaning and

        changing of nets would be prohibitive.

             Copper-based anti-foulants, in widespread use in Mississippi

        and Gulf waters, should be used. Newly developed anti-fouling

        waxes for nets would also be appropriate. In any event, the

        intent to use anti-foulants should be reported and reviewed by

        BMR in advance. The use of anti-fouling compounds with a known

        adverse effect on (non-target) marine life or human health should

        be restricted.


             b) Pharmaceuticals

             Fish culturists in the United States have extremely limited

        che motherapeutic options (G. Jensen, National Program Leader,

        USDA Aquaculture Extension, Washington, DC, personal

        communication). Only one topical treatment and three feed

        additive antibiotics are currently licensed by the Food and Drug

        Administration for food fish culture in the United States. One

        antibiotic, sulfamerizine, is no longer marketed. Romet 30, a

        potentiated sulphonamide approved for use in catfish and

        salmonids has not been approved for either redfish or hybrid

        striped bass culture. The work on the remaining antibiotic,

        oxytetracycline, and formalin, the topical anti-ectoparasite, on

        striped bass/hybrids has been completed and has been sent to the

        FDA for review (op. cit.).


                                        33









              Formalin treatment has been approved for a variety of fish

         species and will probably gain approval for use on hybrid striped

         bass in the near future. Because formalin is generally applied

         as a bath to fish held in tanks for treatment (Federal Register

         1986a) and is not applied to open water net pens, there is'no

         expected environmental effect so long as the treatment waste is

         disposed of in an approved manner.

              Oxytetracycline (OTC) is a broad spectrum antibiotic useful

         in the treatment of many fish diseases (Weston 1986a, 1991a). It

         shows great potential for use in warm water marine fin fish

         culture and, when approved for use on hybrid striped bass, is

         likely to become the drug of choice for net pen culture in the

         Gulf. Oxytetracycline is administered as a food additive at a

         rate of 2.5 - 3.75 g per 45 kg (100 lbs.) of fish per day over  a

         10 - d treatment period (Federal Register 1986b). A 21 day

         holding period is required before fish treated with

         oxytetracycline can be harvested for human consumption.

              The heavy use of antibiotics in the fish farming industry of

         some countries has prompted concern about the quantity of

         antibiotics released into the marine environment and the

         potential effects of these releases. There are four major areas

         of concern (Weston 1991a): 1) antibiotic accumulation in marine

         biota, 2) persistence of antibiotic residues in marine

         sediments, 3) development of antibiotic resistant bacterial

         strains (and the potential transmission of this resistance to

         human pathogens), and 4) alteration of sediment microbial


                                         34









        community structure. Data on these environmental effects is

        severely limited.

             This discussion (based on Washington Department of Fisheries

        1990, Weston 1986a, 1991a) will focus on how these effects relate

        to oxytetracycline use because of pending FDA approval for use of

        this drug in striped/hybrid bass culture and because the scanty

        research on the environmental effects of antibiotic usage have

        concentrated on this drug.

             OTC is widely used as a human medicine. It is also used as

        a routine feed supplement in the diets of chickens, pigs and

        cattle. However, unlike its use in humans or fish culture,

        where it is only used for periodic disease treatment, it is given

        to livestock on a continuous basis. Despite extensive use of OTC

        in treatment of fish diseases in the U.S. and elsewhere, there

        has been no demonstration of significant environmental effects

        (Weston 1986a, 1991a). Many investigators and others have raised

        the issue of potential adverse effects of antibiotic use in net

        pen aquaculture, but, with few exceptions, the discussion has

        remained speculative. There has been no evidence of any

        detrimental effect and little or no data to argue against an

        effect (see reviews in Weston 1986a, 1991a).

             a. Antibiotic accumulation. A large proportion of the

        oxytetracycline supplied to fish-through medicated feed will be

        released into the environment through waste feed and, because of

        the limited digestive absorption of the drug in fish (Cravedi et

        al 1987), through feces. This has been cited as a potential


                                        35









         threat to oysters, shrimp, crabs, and fish living close to

         culture sites. However, the probability of this presenting a

         problem is remote. The concentrations of antibiotics outside    the

         immediate vicinity of the fish farm are regarded by most

         investigators as too low to have any adverse effects (Washington

         Department of Fisheries 1990).

              Austin (1985) reviewed the effects of antimicrobial

         compounds escaping into the marine environment from fish farms.

         While data on the quantities of these materials entering the

         environment are not available, research-results provide estimates

         of probable concentrations for freshwater situations. As a worst

         case scenario, Austin (1985) estimated the dilution of OTC to be

         1:50,000,000, leading to the conclusion that only minute

         quantities of the drug reach the environment. Weston (1986a)

         calculated a concentration level of 3 ppb OTC in a parcel of

         water passing through a net pen receiving medicated feed.

              Field and laboratory research have demonstrated that   OTC

         does not bioaccumulate (Bureau of Veterinary Medicine 1983, cited

         in Weston 1991a). Katz (1984, cited in Washington department of

         Ecology, 1989) concluded that there should be no bioaccumulation

         of OTC in treated lobsters. Oysters suspended near net pens

         containing fish fed medicated feed were free of OTC residues

         (Tibbs et al 1988, cited in Weston 1991a). There are, however,

         some reports of OTC residues in wild fish and shellfish in

         Scandinavian studies (see Weston 1991a).   These results suggest

         that additional information on the environmental persistence of


                                         36









        OTC under varying conditions is needed. However, there appears

        to be no threat of antibiotic accumulation in resident marine

        fauna in the vicinity of aquaculture operations because of

        dilution and dispersion of OTC bearing waste (Maine Department of

        Marine Resources 1991, Washington Department of Ecology 1989,

        Washington Department of Fisheries 1990, Weston 1986a, 1991a).

             b. Persistence of antibiotics in sediments. OTC appears to

        persist in marine sediments, especially under the anoxic

        conditions common under most net pen fish farms (Weston 1986a,

        1991a). Laboratory studies and field observations indicate a

        half-life of OTC in-sediments of at least 10 weeks. (Jacobsen

        and Bergind 1988). Because there has been no demonstrated

        detrimental effect of sediment antibiotics on resident macrofauna

        on the microbial community (Weston 1991a), the significance of

        this is open to speculation.

             C. Antibiotic resistance. Austin (1985) noted that the use

        of antibiotics in fish culture could lead to increased antibiotic

        resistance among the resident bacteria in the facility effluent.

        Oxytetracycline resistance has been noted in two common catfish

        pathogens, Edwardsiella (Sinderman 1990) and Aeronomas (MacMillan

        1985), and resistance may persist for long periods in bacterial

        populations (Levy and Novick 1986), until diluted with non-

        resistant strains.

             While the development and persistence of antibiotic

        resistance among opportunistic fish pathogens is of obvious

        concern to the fish culturist, other potential consequences are


                                       37










         unclear. As will be discussed in a subsequent section, wild fish

         are less susceptible to disease than stressed, closely held

         cultured fish. Infection of wild fish has not been viewed as a

         concern (Maine Department of Marine Resources 1991, Washington

         Department of Ecology 1989, Washington Department of Fisheries

         1990, Weston 1986a, 1991a).

              There has been speculation that antibiotic resistance can

         potentially be transferred to bacteria of human health

         significance. This is not a concern. Fish pathogens possibly

         developing antibiotic resistance are not pathogens of humans

         (MacMillan 1985,, Sinderman 1990). Transfers of antibiotic

         resistance among species of bacteria appear to be laboratory

         phenomena that require highly controlled conditions    While local

         water temperatures (25'C/77*F) meet one of the requirements for

         drug resistance transfer (Toranzo et al 1984), such an event is

         highly unlikely. There is no evidence of such a transference

         occurring in Japan, where conditions are suitable, a wide range

         of antibiotics are extensively used and human pathogens are

         present in the culture water (Washington Department of Fisheries

         1990, Weston 1991a). Sewage effluent and runoff from livestock

         growing areas are greater sources of antibiotics in coastal

         waters than the aquaculture industry could be in the near future

         (Weston 1991a).

              d. Impacts on microbial community structure and function.

         The levels of OTC expected to reach the sediments under worst-

         case conditions (Weston 1986a, 1991a) are not expected to have an


                                         38









        inhibitory effect on non-pathogenic bacteria (see review in

        Washington Department of Fisheries 1990). Samuelson et al (1988)

        and others (see Weston 1986a, 1991a, 1991b) have reported

        decreases in sediment microbial density associated with

        antibiotic treatment. However, the significance of these

        findings is questionable. Effects were not consistent and were

        often associated with antibiotic types and dosage rates

        prohibited in the U.S. There is no indication that application

        of OTC or other FDA approved antibiotics, following established

        FDA and industry guidelines, would significantly alter the

        structure or function of the sediment microbial community.

             e. Mitigation of antibiotic effects. Mitigation of

        antibiotic effects follows two approaches. Only antibiotics

        approved by the FDA should be used, in approved doses and

        following approved treatment methods. Second, the culturist

        should follow good husbandry practices. The frequency of

        antibiotic use is a function, in part, of fish husbandry

        practices. Many of the bacteria of concern to aquaculturists are

        facultative pathogens, becoming a problem only when the fish are

        stressed. The frequency of infection and the resulting need for

        antibiotics can be reduced by keeping stocking density and waste

        loads within the capacity of the site, maintaining clean nets to

        maximize water flow and removing dead fish promptly. Critical to

        good husbandry practices are a thorough understanding of site

        water quality characteristics, their variation and the carrying

        capacity (maximum loads of fish and feed).


                                        39









              f. Other pharmaceuticals. Two points should also be

         considered in planning and regulating future use of

         pharmaceuticals in net pen aquaculture.

              Vaccines have been developed for salmonids and other fish

         species. Vaccines reduce the probability of infection among

         immunized fish, leading to less antibiotic use. While

         vaccination will never replace antibiotic treatment (immunity

         does not last the life of the fish and stress can reduce immunity

         as well), it can significantly reduce the quantity of antibiotic

         used per unit of production. Development and use of vaccines for

         warm water fish in Mississippi coastal waters should be

         encouraged.

              Hormones are commonly used for gender control or to induce

         ovulation. While little is known of the potential environmental

         effects of the'se hormones, the quantities used are so small that

        .no adverse impact is anticipated. No human health concerns are

         associated with hormone use in fish culture (Weston 1991a)

         because they are either administered to juveniles long before

         human consumption or to broodstock that would not be marketed.

         5. Interactions With Resident Species.

              a) Genetic impacts. The escape of cultured fish from

         offshore net pen operations is inevitable. This has raised

         concerns in other regions about possible detrimental impacts on

         local fish populations (Maine Department of Marine Resources

         1991, Washington Department of Ecology 1989, Washington

         Department of Fisheries 1990, Weston 1986a, 1991a). This concern


                                        40









        does not appear to have merit for Mississippi or northern Gulf

        waters.

             Genetic impacts may be important where native species or

        distinct stocks of fish may be threatened. Because net pen

        culture in coastal Mississippi waters in the near future would

        probably be limited to species already present in Mississippi

        waters (e.g. redfish or hybrid striped bass), no genetic threat

        is evident.

             Redfish will not be genetically affected. It has not been

        clearly established whether Gulf redfish can be separated into

        identifiable sub-populations associated with specific areas (Gulf

        of Mexico Fishery Management Council 1984). "Exotic" redfish

        will not be introduced. Seed stock for redfish culture are


        produced from primarily Gulf coast brood stock. Cultured redfish

        have been repeatedly released in all of the Gulf states' waters.

             Gulf and Atlantic race striped bass as well as hybrid

        striped bass have been stocked in northern Gulf waters since the

        1960's (Lukens 1988). There is no evidence of discrete sub-

        population of striped bass or hybrids (Weston 1991a). Hatchery-

        produced fish, which from the basis of the Mississippi

        striped/hybrid bass population, are derived from parental stock

        taken from a variety of areas. These observations suggest that

        there is no threat of detrimental genetic effects associated with

        escaped fish.

             b) Introduction of exotic species. The introduction of

        non-native species and associated pathogens probably represents


                                        41









         the greatest environmental threat of aquaculture. If offshore

         aquaculture is limited to species from the Gulf and Atlantic

         waters, the probability of an accidental introduction of either

         is low. Broodstock, reproductive products and fingerlings of

         redfish, striped/hybrid bass and oysters have a long history of

         movement between Gulf and Atlantic waters. There do not appear

         to be any diseases within the ranges of these species that could

         potentially be introduced by future transfer of seedstock.

         Similarly, there do not appear to be any macrofaunal pest species

         that could be transferred from Atlantic waters with seedstock.


         Purposeful introductions of non-native marine species are

         controlled under the provisions of the Mississippi Aquaculture

         Act.


              c) Transmission of disease from cultured to wild fish.

         Concern has been expressed that cultured fish could act as

         reservoirs of disease infecting wild fish populations. Despite

         the proliferation of cage culture world wide, such an occurrence

         has never been documented (Washington Department of Fisheries

         1990). In fact, there are several examples of diseases that have

         had adequate opportunities to infect wild fish but have failed to

         do so (Weston 1986a). Viral hemorrhagic septicemia and whirling

         disease, both thought to be endemic to Europe, are serious

         diseases of rainbow trout imported to Europe and held in cage

         culture. Wild fish have failed to show symptoms of the disease,

         even after experimental infection.





                                         42










            Diseases observed in the culture of striped/hybrid bass and

        redfish are non-exotic. They exist naturally in the marine

        environment. In a farm environment, these diseases may originate

        from wild fish, infecting cultured stock. Vibriosis is a disease

        of many fish species caused by the bacteria Vibrio species.

        Vibrio spp. are a natural component of marine microbial

        communities world wide and commonly present on wild and cultured

        fish. Vibrio spp. are not pathogenic unless the host fish is

        stressed, as is often the case under culture conditions of

        density and water quality. Other common diseases are also caused

        by facultative pathogenic bacteria.

             While there are many examples of wild fish transmitting

        diseases to cultured fish (see review in Weston 1986a, Washington

        Department of Fisheries 1990), there are no known examples of a

        culture operation providing a reservoir for infection of the wild

        fish population (Weston 1991a). A review of the technical

        literature suggests that the risk of transmission of disease from

        farmed to wild stock is minimal. Existing regulations will

        prevent the importation of exotic pathogens that could

        potentially pose a threat to native fish. Control of potential

        disease vectors at the facility, such as removal of dead fish,

        will prevent the spread of any potential infectious agent.

             At least one author has speculated that shellfish can be

        reservoirs for fish pathogens such as viruses (Meyers 1984).

        Although viruses pathogenic for freshwater fish have been

        isolated from oyster stocks, there is no evidence to suggest that


                                       43











         there is a mechanism for disease transmission from shellfish

         stocks to wild fish (Washington Department of Fisheries 1990).

              Vibriosis has also been reported to affect oysters,

         especially larval stages (Elston 1984). The problem, however,

         appears only under intensive hatchery culture conditions and is

         controlled by improved husbandry practices. There is no evidence

         that vibriosis is important in limiting natural populations of

         oyster larvae (Washington Department of Fisheries 1990). There

         does not appear to be any potential for disease transmission from

         cultured fish or oysters to natural fish or shellfish

         populations.

              d) Interactions with protected species. Thirty three

         species of cetaceans (six endangered) have been reported from the

         Gulf of Mexico (Minerals Management Service 1991). Existing

         regulations provide adequate protection, and offshore aquaculture

         is not expected to significantly affect these species.

              Five species of marine turtles are found in the Gulf of

         Mexico (Minerals Management Service 1991). The loggerhead has

         been reported to nest on the Mississippi barrier islands, and the

         green turtle may occasionally nest in the northern Gulf as well.

         Offshore Mississippi waters are areas of significant use by sea

         turtles. Because they feed chiefly on marine invertebrates,

         offshore fin fish or oyster aquaculture should not attract sea

         turtles as predators. However, the potential for interaction

         among sea turtles and off shore aquaculture remains unknown.




                                         44









             Concerns have been raised, however, that lights on offshore

        structures may affect the behavior of nesting and hatchling sea

        turtles. The recommended separation distances should be adequate

        to avoid having activity on the structures or on-board lights

        disturb sea turtles nesting on the barrier islands. A proportion

        of hatchling sea turtles have been reported to be disoriented and

        drawn towards lights immediately after emerging from the nest.

        This orientation towards light is known to affect hatchlings in

        their passage between the nest and the sea. Information on the

        effect of surface lights on swimming hatchlings is incomplete.

        Recommended separation distances between potential nesting sites

        and offshore aquaculture structures should be adequate to protect

        hatchlings from disturbance or disorientation. Because there is

        no evidence to support or refute the suggestion that hatchlings

        will be drawn towards and congregate around aquaculture

        structures, a subjective determination of adequate separation

        distance between lighted offshore aquaculture facilities and

        nesting beaches will have to be made by the Bureau of Marine

        Resources and the relevant federal agencies on a case by case

        basis.


             Coastal and marine birds are abundant in the northern Gulf

        (see Minerals Management Service 1991 for a review). Piscivorous

        species that may be attracted to net pens include waterfowl such

        as mergansers, shorebirds (e.g. gulls, terns, cormorants), waders
        and raptors. Bird predation on cultured fish stocks, especially
        juveniles, is of concern to aquaculture operations while the


                                        45









          effects of predator control measures is of concern to regulatory

          agencies. Of particular concern are endangered and threatened

          bird species which may prey on cultured fish. These include bald

          eagles (which nest on the barrier islands) and brown pelicans.

               Control of bird predation must follow established federal

          guidelines for such activities and conform to the requirements     of

          the various regulations in place to protect threatened,

          endangered and migratory birds. Proposed control plans should be

          coordinated with the responsible agencies through the Bureau of

          Marine Resources.


               Setting appropriate separation distances away from nesting

          areas or important habitats will minimize impacts on these

          species.   Based on reviews of regulations in other states and

          provinces with commercial net pen aquaculture industries (see

          summary in Owen 1988, and Maine Department of Marine Resources

          1991, Washington Department of Fisheries 1990), a 1/4 to 1/3 mile

          separation between bird habitats and culture sites has been

          generally agreed upon as adequate. Impacts on piscivorous birds

          can be further minimized by use of predator control netting,

          especially over pens holding small fish, and other non-lethal

          control measures.




                                Recommended Guidelines

               A synthesis of the available studies on the environmental

          impacts of net pens draws two important conclusions. First, the

          proper siting of net-pens can assure the dispersion of both solid


                                           46









        and dissolved wastes and the pro tection of sensitive areas.

        Second, environmental effects of net pen culture are reversible.

        Sediment chemistry can recover on a scale of months, biological

        recovery will follow on a scale of months to years.

             The major potential impacts of offshore aquaculture and

        actions to quantify, regulate and minimize these impacts have

        been identified in a variety of state and national studies. The

        main findings of these studies are:

             1. Solid wastes from both net pen and shellfish aquaculture

        operations will settle to the bottom and affect the benthic

        community immediately beneath the site. Selecting sites deep

        enough and with sufficient currents to disperse these wastes will

        minimize the impact.

             2. Important marine habitats, fisheries resources, public

        lands and endangered or threatened species can be affected by

        aquaculture operations. Determining appropriate separation

        distances and selecting sites away from sensitive or important

        habitats and public lands, in cooperation with the Bureau of

        Marine Resources, will minimize this impact.

             3. Impacts on piscivorous birds can be further minimized by

        use of predator control netting and other non-lethal control

        measures. Control of avian predators must conform with existing

        federal guidelines, and control plans should be developed and

        coordinated with the responsible agencies through the Bureau of

        Marine Resources. In view of the potential impact of bird

        predation on fish culture operations and the effect of control


                                        47










          measures on the birds themselves, it is recommended that the

          applicant identify potential bird predation problems (e.g.

          identify bird concentration points and anticipated foraging

          behavior of potential bird predators) and develop an approved

          predation control plan early in the permit application process.

          Minimum separation distances should consider both existing bird

          concentration points and their anticipated foraging behavior.

              4. Nutrients released from  net pens, especially nitrogen,

          can contribute to phytoplankton production in stratified,

          nutrient poor waters. Siting to avoid areas where nutrient

          depletion occurs and placing limits on total fish production in

          such areas can prevent adverse environmental effects.

              5. Fish culture in warm water conditions can place heavy

          demands on available dissolved oxygen levels. Selecting sites

          deep enough and with adequate current speeds to allow for

          adequate dispersion of wastes, setting appropriate limits on

          total fish production and following low waste feeding practices

          (dry, floating feeds, high digestibility, no fines) will minimize

          adverse impacts. The use of automatic feeders should be closely

          watched. The proportion of wasted feed is significantly greater

          with automatic feeders (overfeeding, fines) than with other

          feeding methods (Weston 1991a).

             . 6. The effect of aquaculture operations on water movement,

          quality and on the benthic environment are not detectable within

          tens of meters of the culture site. Major effects on benthic

          biota, reduction in dissolved oxygen and increased dissolved


                                         48










        nutrient concentrations are limited to within a few meters of the


        culture site.

             7. There is no good evidence for net pens having an adverse

        impact on fish and other nektonic species, transmitting diseases

        to wild fish, contaminating resident fauna with antibiotics or in

        contributing to the development of antibiotic resistant microbial

        populations threatening to human health.

             8. The environmental effects of on- and off- bottom

        shellfish culture are generally limited to those associated with

        sediment deposition.



                                Siting Guidelines



        1. Operation size.

             Because the rate of accumulation of feed, feces and organic

        debris under net pens are related to farm size, regulatory

        programs to detect and control potentially deleterious

        environmental effects should be linked to the size of the


        operation. The recommended degree of monitoring required

        increases with farm size. The following classifications are

        presented as a model. Either may be readily used for northern

        Gulf conditions. While it is recommended that site evaluation

        and monitoring requirements be geared to farm size/production

        level, the number of farm classes is subjective.

             There-are two established methods of classifying net pen

        operations by size. Weston (1986a) and Washington Department of


                                        49









         Fisheries (1990) use annual fish production to divide net pen

         operations into three size classes: Class I, less than 20,000

         lb/yr (10,000 kg/yr), Class 11 20,000 - 100,000 lb/yr (10,000

         45,000 kg/yr), and Class III, over 100,000 lb/yr (45,000 kg/yr).

         The Province of British Columbia (Ministry of Environment 1988)

         uses annual feed consumption, calculated on a dry weight basis

         (see Appendix D), to classify fish farms: Class A operations use

         less than 120 mt of feed (dry wt) per year, Class B 120 - 630 mt

         and Class C over 630 mt annually.

         2. Depth and Current Speed

              Site current and depth characteristics are matched with

         production level or feed usage rates to determine the extent of

         environmental impact. However, because of the relatively shallow

         depths and low current speeds in Mississippi waters and in the

         northern Gulf, it may be more appropriate to evaluate permits on

         a site specific basis. This will require a thorough survey of

         pre-operations site conditions, and estimates of potential waste

         loads, DO and BOD demands, sedimentation and nutrient-inputs

         based on net pen design, array, loading and feed use. This would

         be most effective if the survey and monitoring requirements were

         geared to farm size..

              A precedent for this approach exists. Maine does not adhere

         to rigid farm size definitions but considers each permit request

         on a site specific basis. This approach requires that

         hydrographic and benthic data be collected in advance of

         construction to adequately characterize the site. Because the


                                         50









        state assumes the responsibility for the collection and analysis

        of this data in Maine, farm size is less of an issue. Where the

        permit applicants are required to collect this data, the

        requirements are geared to farm size.

             Regardless of size, minimum recommended water depth (MLW)

        beneath the bottom of net pens should be at least two times the

        height of the side facing the prevailing current. Maintaining

        this depth will insure that current velocities beneath the pen

        are not reduced by the structure.

             The main functions of currents are to supply dissolved

        oxygen, to dilute dissolved nutrients and to disperse solid

        wastes. Current speeds and direction in coastal Mississippi

        waters are seasonally variable and generally weak. Surface and

        bottom currents in the area often differ in speed and direction

        as well.


             Low current velocities have several implications. The

        arrangement of the net pens will be affected. the velocity of

        currents passing through net pens is appreciably reduced. In

        weak current areas, below 5 cm/sec velocity, passage through even

        a single cage will reduce velocity to near zero. In such areas,

        net pens must be arranged in a single row perpendicular to the

        prevailing current.

             Depending on the site, the direction and velocity.of the

        surface currents may change on several time scales (daily to

        seasonal). Major seasonal changes may require periodic

        relocation of the net pens.


                                        51









              Spacing between net pens should be at least 2 structure

         diameters. Rows should be at least 20 structure diameters apart.

         Based on experiences in other states, distances between farms

         should be no closer than 600 m (2000 ft).

              The availability of dissolved oxygen for respiration and BOD

         will be limited by low current velocities. Oxygen consumption

         rates of the fish species targeted for net pen culture in the

         Gulf are not well known. In warm water conditions, oxygen

         consumption levels of redfish will be "high" (Neill 1987),   and

         hybrid striped bass will consume up to 800 mg/l (Kruger and

         Brocksen 1978). Summer DO saturation levels are expected to be

         relatively low (say, 6.8 mg/l at 280C and 25 ppt). Under these

         circumstances, low current velocities within the net pens may

         seriously affect fish culture operations.

              Assuming that current velocities within  cages are reduced to

         40% of upcurrent velocities and that most sites in Mississippi

         coastal waters will have surface currents less than 8 cm/sec,

         both loading rate (fish/M3 ) and total farm size will be limited

         by current velocity and available dissolved oxygen.

              Prevailing current velocities in coastal Mississippi will be

         insufficient to appreciably disperse solid wastes from beneath

         the net pens. Because the BOD of the solid waste can be up to

         three-times the respiratory oxygen demand of the fish, oxygen

         depletion of bottom waters is a very real concern. Farm size and

         loading rates will have to be limited by current speed and

         seasonally variable dissolved oxygen levels available for both


                                         52









        respiration and BOD. Because of anticipated high BOD and low

        summer DO levels, minimum depth below the net pen must be

        determined by the anticipated maximum waste load. While the

        determination of current speeds within net pens and the

        calculation of waste loads, sedimentation rate and dispersion,

        and respiration and biochemical oxygen demands are imperfect, the

        suggested methods should serve as a basis for the evaluation of

        potential environmental impacts of aquaculture.

        3. Areas With Chronic Water Quality Problems.

             Net pens should not be located in areas subject to nutrient

        depletion in surface waters (total nitrogen less than 0.1 mg/1)

        or in areas subject to vertical stratification of the water.

        A stratified water column tends to be depleted of nutrients,

        while bottom waters are prone to reduced dissolved oxygen

        conditions.


             Large areas of the northern Gulf, in Louisiana coastal

        waters are subject to periodic anoxia resulting from

        stratification. Mississippi coastal waters are often partially

        stratified in the spring and summer months (Kjerfve and Sneed

        1984, Minerals Management Service 1991, USEPA 1990).

             Nutrient inputs to nitrogen-poor surface waters may

        contribute to unwanted phytoplankton productivity. Solid waste

        inputs may compound near bottom dissolved oxygen problems in

        stratified water bodies. These effects will be magnified in

        areas with fine sediments, where BOD is already high.




                                        53










              To minimize the likelihood that aquaculture operations will

         adversely affect water quality or contribute to phytoplankton

         productivity, limits may be placed on fish production within

         Mississippi coastal waters, pending the collection of essential

         current and water quality data to allow an evaluation of the

         site. On a qualitative basis, production levels will be limited

         in stratified waters, nutrient depleted waters and, assuming a

         standard pen height of 4 m, in waters less than 12 m deep.

         4. Habitats of Special'Significance.

              Habitats and species of special significance to be protected

         from adverse environmental effects have been identified in all

         regions. Selecting sites away from sensitive or important

         habitats and public lands will minimize impact from offshore

         aquaculture. Maine requires a minimum of 1/4 mile separation

         between aquaculture sites and p4rks, wilderness areas, critical

         habitats for endangered/threatened species and sensitive

         fisheries related habitat. Washington defines a variety of

         minimum separation distances from 300 feet to 1,500 feet.

         British Columbia and New Brunswick require 1000 m. However,

         external activities that impact  park values and resources, even

         those falling outside park jurisdictional areas, may require

         greater separation distances based on site specific conditions.

              Because of reduced current velocities in Mississippi waters,

         the effects of aquaculture operations would be spatially limited.

         While it appears that only minimum distances (150 - 300 ft.)

         would be required to avoid impacts on seagrass beds, oyster


                                         54









        reefs, artificial reefs, spawning areas and other fishery

        resources, actual separation distances will have to be determined

        on a case by case basis. As with other separation distance

        guidelines, permits should identify that separation distances may

        be increased to reduce any potential impacts on these habitats.

        Following recommended depth guidelines will minimize the

        potential for locating aquaculture operations in close proximity

        to sea grass beds.

             Prudence dictates avoiding net pen locations in areas with

        large concentrations of piscivorous birds (e.g. pelicans, terns),

        their nesting sites or near nests of fish eating raptors

        (ospreys, eagles). In view of the potential impact of bird

        predation on fish culture operations and the effect of control

        measures on the birds themselves, it is recommended that minimum
        separation distance's should consider both existing bird

        concentration points and their anticipated foraging behavior.

        Based on federal and state guidelines of aquaculture in other

        regions a minimum of 1/4 mile separation between bird

        concentration areas and the net pens is recommended.

             Net pens located closer than a certain minimum distance from

        bird nesting or concentration areas (1/4 mile in northern

        regions) may serve as an "attractive nuisance", drawing birds to

        the site. Based on limited observations, however, birds appear

        to visit sites located beyond this minimum distance (but within

        the normal foraging range) with about equal frequency. It is

        critical to identify and establish this minimum distance (buffer


                                        55









         zone) for all bird species that may be affected by the operation.

         The permit should specify that the separation distance

         requirement may be increased if it is determined that the number

         of bird visits exceeds an accepted frequency.

              A minimum of 1/4 mile should separate aquaculture operations

         from any park, wilderness area, beach or areas used or frequented

         by protected animal or bird species. This would include sea

         turtle nesting grounds. No sensitive areas for marine mammals

         have been identified in Mississippi coastal waters. However, any

         permit granted to a aquaculture facility should specify that if

         any critical habitats or sensitive areas are identified and are

         affected by the operation, the permit may be altered. An

         alteration of permit conditions may also be required should

         aquaculture operations affect threatened or endangered species.



         5. Dredged material disposal areas, maintained waterways and

         other areas of concern.


              While not technically an environmental concern or habitat of

         special significance, navigation channels, open water disposal

         areas and other sites permitted for specified uses are not

         suitable for siting aquaculture operations. Because of the

         potential conflict arising between dredging and disposal and

         aquaculture operations, net pens and shellfish culture operations

         should not be located in close proximity to these activities.

         On-bottom shellfish structures should not be within 1500 feet of

         either a dredged channel or a disposal area. Because most


                                         56









        suspended sediment effects of dredging are confined to bottom

        waters, net pens in water over 12 m deep should be located no
        closer than 5'00 ft. of a navigation channel. At least 1500-ft.

        should separate shallow (<12 m) net pen operations from

        maintained navigation channels and separate all net pen

        facilities from designated open water disposal sites. Seasonally

        variable current direction and velocity negate any possibility of

        closer siting "up current" of dredging or disposal operations.

        These distances should be reviewed and established on a case by

        case basis.


             While these guidelines do not specifically address esthetics

        issues, it is important to note that these considerations will be

        taken into account in reviewing permits. Specifically, the

        presence of wilderness areas, marine sanctuaries, recreational

        areas and national seashores in the northern Gulf of Mexico will

        affect the siting, operations and monitoring requirements for

        aquaculture operations. No attempt has been made in this report

        to address other important concerns such as conflicts with other

        users, social impacts and related issues.

                           Pre-operations requirements

             These guidelines are not intended to be all-inclusive.

        Rather, they identify some of the important pre-operations

        requirements that bear directly on operational and monitoring

        guidelines.







                                       57






               1. Permit applicant must document'financial resources for

          the proposed project, demonstrating the capability to perform as

          specified in the permit conditions.

               2. The permit applicant must provide information regarding

          the professional expertise of the on-site operations staff. This

          must be sufficient to demonstrate an ability to accomplish the

          proposed project.

               3. Permit applicant may be required to post a performance

          bond to ensure compliance with operations and monitoring

          conditions. An additional bond may be required to ensure cleanup

          in the event of a fish kill or other pollutant discharge, or to

          allow for the and cleanup of the site after destruction or

          abandonment.


               4. Working with the Bureau, the permit applicant must

          identify shellfish beds, submerged vegetation beds and essential

          habitats/endangered or threatened species found in the

          surrounding area.

               5. Should a permit request be denied because  the proposed

          operation does not satisfy recommended site selection,

          evaluation, operations and monitoring guidelines presented here,

          the burden of proof that there will be no significant

          environmental effect associated with the operation should fall on

          the applicant.








                                         58










                         Site Characterization Survey.

            Because of the large number of areas in Mississippi waters

        where potential water quality problems and adverse environmental

        impacts may occur, it is essential that all sites considered for

        aquaculture operations be surveyed and characterized. This

        survey must be completed before the permit application and should

        include: a) a bathymetric survey, b) hydrographic survey and c)

        a diver survey to visually assess the area and its biological

        resources. Applicants for permits should be strongly encouraged

        to consult with the Bureau of Marine Resources officials prior to

        completing a permit application and designing the site

        characterization survey. Appendix B provides an outline of a

        baseline survey.

             An overview of the information needed to coordinate the

        survey is provided in Appendix A, including site location,

        development plan and operations plan. These will be combined

        with survey data to determine the suitability of the site for the

        described operation, any potential adverse environmental impacts

        and any proposed mitigation approaches.



                              Operations Guidelines

             1. A baseline survey should be completed for large (>630 mt

        of feed used, dry weight, per year; in excess of 100,000 lbs.

        fish annually) operations after construction but before

        operations commence. Recommended guidelines for the baseline

        survey are shown in Appendix B.


                                        59









               2. All waste discharge permits should have the condition

          that discharges meet state water quality standards (State of

          Mississippi 1991) for dissolved oxygen, temperature, Ph,

          turbidity, toxic or deleterious materials and fecal coliforms

          (temperature and Ph effects are not expected to occur).

               3. The receiving water mixing zone will be defined by the

          State and water quality standards will not apply in the mixing

          zone adjacent to or surrounding the site. The area/volume of the

          mixing zone should be limited so as to minimize mortality of

          important fish or shellfish. A suggested mixing zone of 100 ft.

          around the perimeter of the facility should be sufficient to

          mitigate discharge and turbidity effects of both normal culture

          and cleaning operations.

               4. Discharges of any fish carcasses, fish processing waste,

          sewage or other waste beyond feed, fish feces and debris from

          fouling organisms should be prohibited.

               5. To minimize nutrient inputs, only dry pelleted feed

          should be used. Floating pellets, preferably formulated

          specifically for the cultured fish species to maximize

          digestibility, should be used. Fines should be removed prior to

          feeding and automatic feeders should be discouraged.

               6. Operations should use non-lethal methods of predator

          control and all methods must comply with state and federal

          requirements.

               7. Toxic and deleterious substances





                                         60









             a) Net fouling control chemicals. The discharge of

        antifoulants which may affect water use or adversely affect

        aquatic biota or human health should be prohibited. The intended

        use of antifouling agents should be reported and reviewed by

        state environmental management agencies.

             b) Only antibiotics licensed by the FDA for use on the

        target fish species should be allowed for use. Oxytetracycline

        and formalin are expected to receive approval soon for use in

        hybrid striped bass culture. Only two other theraputants, Romet-

        30 (a combination of sulfadimethoxine and ormetoprim) and

        sulfamerazine (not presently marketed), and an anaesthetic, MS

        222 or Finquel, have FDA approval for use on fish.

             Antibiotics should be used strictly on a short term basis

        for disease treatment or prevention. Long-term prophylactic use

        should be prohibited. The Bureau should be notified of all

        antibiotic use at the time of treatment and notified of the

        disease condition treated and type of dosage of antibiotic used.

             Concern about the environmental risks by disease prevention

        medications appears to be minimal. Although it is expected that

        antibiotic use in fish culture will be relatively frequent, given

        the warm water temperatures and other potentially stressful

        conditions in this region, there does not appear to be a risk of

        the development of antibiotic resistant bacteria or accumulation

        of antibiotics in marine organisms. Similarly, there   does not

        appear to be a risk of disease transmission from farmed fish to

        wild stocks.



                                        61









              Should the frequency of antibiotic use at a fish farm

         increase markedly, measures to reduce the frequency of infection

         and the need for antibiotics should be employed. These include

         reducing stocking density, more frequent net cleaning, prompt

         removal of dead fish and other measures to improve water quality.

         Permits should specify that these actions may be required.

              Vaccinations are likely to become important in warm water

         fish culture disease control in the near future. Provisions

         should be made to encourage the use of vaccinated fish to reduce

         antibiotic use.


              c) Hormones (especially methyltestosterone) have been used

         in aquaculture. Little is known of their potential environmental

         impact. While there is no indication that hormones will be used

         in net pen fish culture in Gulf of Mexico waters, the quantities

         used are so small and so early in the life of the fish that no

         major effect is anticipated. Hormone treatment for sex reversal

         should not be prohibited.

              8. All importation, transfer and possession of live fish or

         their reproductive products must comply with state and federal

         regulations.



                               Monitoring Guidelines

              Monitoring programs should be geared to the size of the

         operation. Washington State guidelines recommend annual

         monitoring surveys for net pen operations over 20,000 lb annual

         fish production (Appendix C). These include a benthic survey and


                                         62









        a diver survey for operations producing between 20,000  100,000

        lbs. annually. Large operations (>100,000 lb/yr) are required to

        complete a more comprehensive survey, including sediment

        chemistry, benthic infauna, water quality sampling and current

        information in addition to diver and benthic surveys.

             The British Columbia government has developed a model annual

        monitoring program (Appendix D). With modifications, this is a

        useful model for Mississippi waters. This system divides farms

        into three size categories by the quantity of feed used and

        prescribes increasingly complex monitoring requirements with

        increasing quantity of feed used. Data forms and standard

        methods for use in the annual monitoring program have been

        developed as well and are attached as Appendices F and G.




























                                       63












                                      REFERENCES



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          Alabaster, J.S. 1982. Report on the EIFAC workshop on fish farm
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        Gulf  of Mexico Fishery Management Council. 1984. Fishery
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        Hall, P.O., L,G. Anderson, 0. Holby, S. Kollberg and M.A.
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         Kruger, R.L., and R.W. Brocksen. 1978. Respiratory metabolism
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         Kusuki, Y. 1977. Fundamental studies on the deterioration of
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         Levy, S.B., and R.P. Novick. 1986. Antibiotic resistance genes:
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         Liao, P.B., and R.D. Mayo. 1974. Intensified fish culture
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         Maine Department of Marine Resources. 1991. Joint State/Federal
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        Mattison, J., and 0. Linden. Benthic macrofauna succession under
             mussels, Mytilus edulis L. (Bivalvra), cultured on hanging
             long -lines. Sarsia 68:97-102.

        Meyers, T.R. 1984. Marine Bivalve molluscs as reservoirs of
             viral pathogens: significance to marine and anadromous
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        Minerals Management Service. 1991. Final Environmental Impact
             Statement, Gulf of Mexico Sales 139 and 141, Central and
             Western planning areas. Publication No. OCS EIS/EA MMS 91-
             0054. Minerals Management Service, New Orleans, LA.

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             for marine fish farms. Waste Management Branch, Ministry of
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             G.W. Chamberlain, R.J. Miget and M.G. Haby, editors, Manual
             on red drum aquaculture, pp. IV-1 to IV-8. Texas
             Agricultural Extension Service publication, Corpus Christi,
             TX.

        Nosho, T. 1989. Small-scale oyster farming for pleasure and
             profit. Washington Sea Grant Publication WSG-AS 89-1.
             Seattle, WA.

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             resources in British Columbia. Public Report No. 15,
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             Oxidation of organic matter in sediments. EPA 660/3-73-005.
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        Pearson, T.H., and R. Rosenberg. 1978. Macrobenthic succession
             in relation to organic enrichment and pollution in the
             marine environment. Oceanography and Marine Biology Annual
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        Pease, B.C. 1977. The effects of organic enrichment from a
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             recirculating systems. In D.L. Swann, editor, Regional
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             systems, November 2-3, Normal, IL, pp. 13-27. Illinois-
             Indiana Sea Grant publication IL-IN-SG-E-90-7.


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         Samuelson, 0., V. Torsvik, P.K. Hansen, K. Pittman and A.Ervik.
              1988. Organic waste and antibodies from aquaculture.
              International Council for the Exploration of the Sea. C.M.
              1988/F:14.

         Shumway, S.E. 1982. Oxygen consumption in oysters: an overview.
              Marine Biology Letters 3:1-23.

         Sinderman, C.J. 1990. Principal diseases of marine fish and
              shellfish Volume I. Academic Press, San Diego, CA.

         Snider, R. 1987. Red tide in Texas. An explanation of the
              phenomenon. Texas A & M Sea Grant College Program
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              intrastate, interstate and coastal waters. Mississippi
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              the occurrence of 'Protogonyanlax sp. at the scallop ground
              in Funka Bay. Bulletin of the Faculty of Fisheries of
              Hokkaido University 31(2):215-221 (in Japanese).

         Tenore, K. R., and N. Gonzalez. 1975. Food chain patterns in
              the Ria de Arosa, Spain: an area of intense mussel culture.
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              Belgium, Sept. 17-23, 1975. Vol. 2:601-619.

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              Crosa. 1983. Characterization of plasmido in bacterial
              fish pathogens. Infection and Immunology 39:184-192.

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              designation of an ocean dredged material disposal site
              located offshore Pascagoula, MS. U.S. Environmental
              Protection Agency, Region IV, Atlanta, GA.

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                                         68










        Weston, D.P. 1986a. The environmental effects of floating
             mariculture in Puget Sound. School of Oceanography,
             University of Washington, for the Washington Departments of
             Fisheries and Ecology.

        Weston, D.P. 1986b. Recommended interim guidelines for the
             management of salmon net-pen culture in Puget Sound.
             Prepared by Science Applications International Corporation
             for the Washington Department of Ecology. Olympia, WA.

        Weston, D.P., and R.J. Gowen. 1988.   Assessment and prediction
             of the effects of salmon net-pen culture on the benthic
             environment. In fish culture in  floating net pens, Appendix
             A. Final Pro4-rammatic Environmental Impact Statement,
             Washington Department of Fisheries (1990), Olympia, WA.

        Weston, D.P. 1991. An environmental evaluation of finfish net-
             cage culture in Chesapeake Bay prepared by the University of
             Maryland J.





































                                        69










          Appendix A.    Environmental Surveys.

          The effect of development on the marine environment is a major
          consideration, so certain site-specific information is required
          for permit review. In order to assess the suitability of a site
          for net-pen or on/off bottom shellfish culture and to evaluate
          the extent of environmental effects after the start of culture
          operations, several environmental surveys are required. These
          include a site characterization survey, a baseline survey, and
          annual monitoring. The components of each of these surveys are
          summarized in Table Al and discussed in the following sections.

                                 < add table Al here>

          A. Site Characterization Survey  . A site characterization survey
          is required prior to permit application. This survey serves two
          principal functions. The primary purpose is to provide state and
          local governments with the information necessary to evaluate the
          potential extent of environmental effects. The site
          characterization survey also provides the applicant with
          information on determining the suitability of a site for culture.
          A site characterization survey is composed of four principal
          elements: (1) initial consultation with state and local
          government; (2) a bathymetric survey; (3) a hydrographic survey;
          and (4) a diver survey.

          1. Consultation with state government. After selecting a
          potential culture site, but prior to performing the site
          characterization field survey, the-prospective applicant   should
          contact state resource management agencies (Departments of
          Wildlife, Fisheries and Parks - Bureau of Marine Resources,
          Environmental Quality, Agriculture). Initial contact should be
          made with the MDWFP Bureau of Marine Resources (BMR). This
          agency will then facilitate consultations with all other
          appropriate state and federal agencies.

          While these consultations cannot be required of the applicant,
          they are highly recommended. They provide state and federal
          local officials with an opportunity to comment on the potential
          site at an early stage in the planning process. They also ensure
          that the required evaluation surveys will be designed to meet
          established requirements. Resource management agencies may be
          able to identify nearby habitats of special significance or
          existing conditions that would make the site unacceptable for
          development. Other government agencies may also need to be
          contacted if the potential site-is likely to affect land or
          resources under their jurisdiction.

          One of the principal purposes of these consultations is to
          determine the proximity of the potential site to habitats of
          special significance. BMR staff may be aware of nearby critical
          habitats or major shellfish beds. BMR may also be able to

                                          70













                                                                   Table Al


                                                   RECOMMENDED ENVIRONMENTAL SURVEYS FOR
                                                      MISSISSIPPI NET-PEN CULTURP




                                   Site Characterization                  Baseline                           Annual
                                          Survey                           Survey                         Monitoring


           Class 1           9 Recommended consultation with       e None                      None
           Facilities          state and local authorities

                             e Bathymetric survey
                             * Hydrographic survey
                                 - Current velocity and
                                   direction

                             9 Diver survey

           Class II          * Recommended consultation with       9 None                      Benthic survey
           Facilities          state and local authorities                                       - Diver survey
                             * Bathymetric survey

                             9 Hydrographic survey
                                 - Current velocity and
                                   direction

                             9 Diver survey

           Class III         e Recommended consultation with       9 Sediment chemistry      o Benthic survey
           Facilities          staLe and local authorities           sampling                    - Diver survey
                             9 Bathymetric survey                  9 Benthic infauna             - Sediment chemistry
                             * Hydrographic survey                   sampling                    - Benthic infauna
                                 - Current velocity and                                      e Water quality sampling
                                   direction
                                 - Drogue tracking                                           * Current velocity and direction
                                 - Vertical hydrographic
                                   profiling

                             a Diver survev









        identify bird nesting sites and colonies, wilderness areas,
        public beaches and parks and other areas of significance. BMR
        can obtain information on endangered, threatened, and protected
        species that may occur in the vicinity of the proposed site.

        State and local government officials should be given an
        opportunity to comment on the proposed field surveys (i.e.,
        bathymetric, hydrographic and diver surveys). The survey content
        should be determined in consultation with BMR and those agencies
        having permit authority. The survey protocol described below is
        intended to provide the information necessary for a standardized
        and cost-effective permit review * This should be adequate in
        most instances, but there may be certain site-specific concerns
        that would require minor modifications. For example, the diver
        survey may be modified to devote particular attention to areas of
        special concern. Departure from this protocol should be allowed
        only with strong justification, and modifications should
        generally result in the collection of more, rather than less,
        data.


        2. Bathymetric survey. A bathymetric survey should be performed
        in order to determine depth and to identify the presence of any
        bathymetric features which might affect bottom accumulation of
        excess feed and fecal material. All permit applicants will be
        required to perform a bathymetric survey. The area of concern is
        the seabed directly under the floating or on-bottom structures
        and within 300 feet of the perimeter of such structures.
        Multiple fathometer transects should be established with a
        density and spacing so as to adequately characterize the
        bathymetry under and around the pens. The position of the
        transects will depend upon the intended configuration of the
        planned structures. Figure Al provides a recommended survey
        design given a rectangular configuration. The bathymetric survey
        report should note the period during the tidal cycle when the
        survey was made, and it should relate the measured depths to
        MLLW (mean lower low water).

                               <add Figure 1A here>

        3. Hydrographic survey. Information on current velocities and
        directions is necessary to determine if current velocities will
        be adequate for dilution and dispersion of excess feed and wastes
        from net pen culture. Current information will also be needed
        for floating shellfish facilities to estimate the potential
        dispersion of wastes. These data are important for operations
        planning, providing essential information on the supply of
        dissolved oxygen supplied by the water flow.

        The hydrographic survey includes three components: (a) current
        velocity and direction; (b) drogue tracking; and (c) vertical
        profiles of temperature, salinity and dissolved oxygen. Class I
        and II net pen facilities, as defined in Table A2 (AppendixC)

                                        71









          will not be required to perform the drogue tracking studies
          because of their small size and reduced potential for water
          quality degradation. Floating shellfish culture facilities     will
          only be required to describe current velocity and direction.
          Only vertical temperature, salinity and oxygen profiles only will
          be required for on-bottom shellfish culture.

               3a. Current velocity and direction should be monitored at
          the center of the proposed site. Both near-surface and mid-depth
          measurements should be made. The near surface measurements
          should be taken at a depth of 6 feet or at one-half the depth of
          the structure. The mid-depth measurements should be taken
          mid-way between the maximum depth of the proposed net-pens and
          the sea floor. At both depths current velocity and direction
          should be monitored throughout one complete tidal cycle (one
          flood tide, one ebb tide). Collect a 15-minute sample at each of
          the three depths. A minimum of ten measurements evenly spaced
          throughout the tidal cycle should be made at each depth. "Mean
          current" is to be determined by an arithmetic average of these
          ten or more measurements. The measurements should be made during
          a period of "average" tides, and should not be representative of
          either extreme neap or extreme spring tides. Subsurface current
          meters are preferred. However, flow meters may be used, but
          surface direction must be estimated. Please provide the current
          data in a tabular format and include the date and tide
          predictions for that day. The report of results should note any
          conditions (e.g., weather, wind speed and direction, tidal gauge
          data for that day) that might make the data unrepresentative of
          "typical" conditions. If there is reason to believe the data do
          not reflect "typical" tidal currents and direction, resampling
          may be required, but all data collected may be used in
          determining a mean velocity.

               3b. Drogue tracking is needed to estimate the potential
          fate of particulate material and the potential for eddy
          circulation (i.e., the same parcel of water is repeatedly cycled
          through the area of the net-pen). Two drogues should be released
          from the center of the potential net-pen site. One should be set
          at a depth of 6 feet. The second drogue should be set at a depth
          mid-way between the bottom of the potential net-pens and the sea
          floor. The trajectory of these drogues should be followed for as
          long as daylight permits, and not less than 8 hours. The drogues
          may be reset at the original release site during this 8-hour
          period if they are transported beyond a practical tracking range.

               3c. Vertical profiles of salinity, temperature and
          dissolved oxygen may be used to evaluate the intensity of water
          column stratification, a factor important both from the
          standpoints of environmental protection and the health of the
          cultured fish. Prospective applicants should provide any
          existing hydrographic information on the site. Site-specific
          studies have been completed in the northern Gulf of Mexico by the

                                           72























                                                                                             300 ft
                                                   POTENTIAL NET-PEN SITE








                                                                                                      300 ft
                                                            Ll Ej F1 D F-I




                                                     BATHYMETRIC TRANSECTS                   300 ft













                                                            I C SITIVI"),       ],'OR qfTE CHARACTERIZATFON









        Environmental Protection Agency, Corps of Engineers (Mobile
        District), Minerals Management Service and researchers working
        out of the Gulf Coast Research Laboratory.

        Measurements of temperature, salinity and dissolved oxygen should
        be taken throughout the water column at the center of the
        potential site during the summer months, June through September.
        Measurements should be made at depths of 1, 10, 20, 30 feet, and
        at 30 foot intervals thereafter. The deepest measurement should
        be made 3 feet above the sea floor. Water samples may be
        collected or an electronic membrane probe may be used. The
        sampling schedule should include one sample taken within one hour
        of slack low water.

             Although the preferred method is the ''Winkler Titration''
        (Azide modification), described in Standard Methods, the use of
        the membrane electrode is acceptable if the zero and standard
        calibration methods described in the instrument manufacturer's
        instructions are followed. If the membrane probe is used, the
        first and last reading of each run must be verified with a
        Winkler Titration of a water sample collected just prior to the
        instrument readings. The verification samples must be fixed when
        collected and titrated in the laboratory as soon as possible
        after collection. The verification samples should be reported
        next to the same readings performed by the probe.

        4. Diver survey. The diver survey is primarily intended to
        determine if habitats of special significance are present in the
        vicinity. Because much of the biological activity in offshore
        Mississippi waters occurs spring through fall, the diver survey
        should be performed April through November. The requirements for
        a diver survey during site characterization depend on the water
        depths in the vicinity of the site. A diver survey is required
        if water depth (MLLW) at the site or within a 300 foot radius of
        the potential location is less than or equal to 75 feet. If any
        portion of this area is in depths of 75 feet or less, it may be
        subject to accumulation of feed and fecal material.

        The design of the diver survey should be formulated in
        consultation with BMR, who will take the lead role for the state
        in design of this survey. The dive should be conducted along the
        axis of the prevailing current. The number and spacing of the
        transects will depend on the particular site and will be
        established during these consultations. As a general guide, 3 to
        5 transects, each 200 feet long, should be surveyed per acre of
        pen/raft surface. A larger complex would require additional
        transects. A diver should follow marked transects making
        observations of substrate type, bottom features (noting erosional
        or depositional areas), presence/absence of Beggiatoa mats, and
        relative abundance of flora/fauna. Abundance may be
        characterized approximately as follows: a) abundant: always
        present within the diver's view; b) common: seen occasionally

                                        73










         throughout the dive, may be patchy; rare: only seen once or in a
         few places throughout the dive. If eelgrass is present, counts
         of turion density in 0.25 m 2 quadrats will be required. Where
         oysters are present, density (per M2 ) and average size should be
         provided.

         5. Report. The results of the bathymetric, hydrographic and
         diver surveys should be assembled in a site characterization
         report to be submitted to the BMR. The report should be a
         summary, analysis and interpretation of the data. The diver
         survey should be described in narrative form with quantitative
         data provided when required or available.The report should also
         include identification of habitats of special significance in the
         vicinity as determined in consultation with the BMR and the
         applicant's own surveys.

         The BMR may require that the diver survey shall be documented
         with a video camera or photographs. One copy of the video tape
         on standard VHS tape format should accompany the application.
         While video format is preferred, photographs taken at 30 foot
         intervals may be submitted if video is not available. A brief
         narrative with the tape or photos describing reference points
         should be provided. All documentation must include the dates on
         which it was taken.


         Information to be provided in the report should include:

               -A.   Vicinity Map. Use a NOAA chart or USGS Topographic
         map to show the waters and shorelands within the general vicinity
         of the lease area. Any aerial photos must have been taken during
         the twelve month period prior to the filing of the application
         and the date on which it was taken must be noted.


               B.    Plan View. Exact location of lease tract(s) described
         as follows:


               a.   Mark each tract and entire lease boundary. Mark true
                    north with arrow. Include scale used.

               b.   Show depth contours and indicate mean low water and
                    mean high water on all land adjace nt or nearest site.

               C.   Show primary ebb and flood directions.

               d.   A figure of the drogue trajectories should be also be
                    included.


               e.   The position of the diver transects.

               f.   Label the location of Federal projects, navigational
                    channels, any structures, weirs, existing leases,
                    parks, etc. within 1 mile. An enlargement of a NOAA

                                          74










                  chart or USGS topographic map is suggested to provide
                  this information. Also provide:

             9-   The latitude, longitude and LORAN coordinates for
                  each corner of the entire lease.


             h.   The metes and bounds of each 5 acre tract.

             C.  Site development. This section is intended to provide
        accurate plans depicting the physical structures of the proposed
        operation. The site characterization report should include a
        figure of the proposed net-pen site in plan view at a scale of
        200 feet or less to the inch.

             a.   Single pen/raft schematic. Provide top view, cross
                  section, identify dimensions, materials, labels, etc.

             b.   Pen system schematic. Provide top view and cross
                  section, identify dimensions, mooring connections,
                  labels, etc.

             C.   On-site support structures. Describe structures such
                  as barges, sheds, feed sheds, etc., to be located
                  on-site. Provide dimensions, drawings, materials, etc.

                       Describe the storage and use of oil, gasoline or
                  other hazardous material on this facility.

                       Describe the type and location of any sanitary
                  facility.

             d.   Mooring plan.

                       Cross section. Provide a schematic and
                  description of materials of the mooring system in place
                  on the sea-floor. Include depths from the bottom of
                  the structure to sea-floor relative to MLW and MHW.

                       Mooring system adequacy. Provide a schematic of
                  the mooring array for a pen system and a description of
                  its ability to withstand severe storms, surge,
                  equipment break-up, etc. Include dimensions and
                  materials, etc.

             e.   Pen system and mooring array schematic. Provide a
                  schematic of the maximum area to be utilized by pen
                  systems and moorings on the proposed lease.

             f.   Upland facilities. Describe shoreside facilities or
                  holdings to be used for various activities including
                  feed transport, processing, etc.


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               D. Operations.

               a.   List and describe your activities including boat
                    traffic, feed schedule, feed techniques, monitoring
                    schedule, transport schedule, predator control methods,
                    net cleaning and maintenance (methods, frequency and
                    location), antibiotic usage, harvest schedule, harvest
                    technique, processing methods.

               b.   Describe the start-up and projected maximum production
                    on a 12 month basis per pen and pen system. Also state
                    the maximum stocking density, in pounds per cubic foot
                    for fish and per square foot of structure for
                    shellfish.


               C.   Estimate the monthly pounds of feed per pen system over
                    12 months at start-up and maximum production.

               E.   Area resources.


               a.  Habitats of special significance/endangered species.
               Oyster beds, submerged vegetation beds and other marine
               resources. Provide a description of any oyster beds, sea
               grass beds and other marine resources in the surrounding
               area. Provide a map showing the location of these resources
               if within a mile of the proposed site.

               Projects cannot be located within one mile of any habitat of
               special significance, such as wilderness areas, critical
               habitats for endangered/threatened species, sensitive
               fisheries habitat, grass beds, bird concentration points,
               etc. Applicants will be required to provide a signed
               statement to confirm the proposed lease either does not fall
               within one mile of such habitats.

               b. Surrounding area use.

               Provide a tax map, chart, or topographic map showing the
               locations of any adjacent or nearby lease tract(s) or
               riparian/littoral property located within 1000 feet of the
               lease tract(s) Property lines must be clearly marked.       List
               the names and addresses of every lease holder or owner of
               riparian rights shown on the map. Identify any fish or
               shellfish culture leases. The map and list of owners must
               be certified by the tax collector or clerk of the
               municipality in which the lease tract is located as being an
               accurate copy of this information as maintained by the
               municipality.

               List all other aquaculture leases held by the applicant or
               in which the applicant has a financial interest. Describe
               the navigational or other uses (ocean disposal, cable, etc.)

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             within one mile of the area. Describe the degree of
             exclusive use required by the proposed lease.

             c. Point source discharge. Describe the location and
             proximity of the proposed lease to any point source
             discharges or facilities (sewage treatment plants, seafood
             processing plants, power plants, industrial facilities,
             stormwater drains, etc.).

             F. Technical capability. Provide information regarding
        professional expertise such as a resume and documentation of
        technical expertise and practical experience necessary to
        accomplish the proposed project.

             G. Financial capability. Provide documentation to prove
        the applicant has the necessary financial resources for the
        proposed project. Provide documentation of accurate and complete
        cost estimates of the proposed aquaculture activities. The
        applicant must post a performance bond, the amount of which will
        be determined by the nature of the aquaculture activities
        proposed and set by the BMR.

































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         Appendix B. Baseline Survey.

         The baseline survey is intended to characterize bottom conditions
         at the site, before they could potentially be altered by culture
         activities. and benthic infauna sampling. The baseline survey
         is required for Class III net-pen operations only and will not be
         required of Class I and II operations or for shellfish culture.
         The baseline survey is to be completed after emplacement of
         net-pens but before stocking.

         The Baseline Field Survey may include components for diver
         observation, hydrography and water quality, but focuses primarily
         on benthic analyses, sediment analyses and sediment chemistry,
         The sediment sampling plan must include the number and location
         of sediment samples to be collected for grain size, chemical and
         biological analysis. The proposed plan should be coordinated
         with BMR to insure that the quality of the sediment analysis and
         infaunal data will be acceptable. Stations should be established
         along a transect on the "downcurrent" side of the pens as
         determined by the prevailing currents (as measured at the
         mid-depth station in the site characterization survey). Stations
         should be established along this transect beginning directly
         under the perimeter of the net-pens and extending away from the
         net-pens at distances of 20, 50, 100, and 200 feet in the
         direction of prevailing currents. Each site should be sampled by
         three replicate diver cores or three replicate grab or box corer
         samples from which sub-cores are removed.

         Cores should be collected for analysis of total organic carbon,
         total Kjeldahl nitrogen and grain size distribution (median phi,
         percent gravel, sand, silt/clay). Cores should be inserted to a
         depth of four inches in the sediment. Care should be taken to
         insure that the core is representative of the undisturbed
         sediment column. Transparent cores should be used so that the
         redox potential discontinuity (RPD) depth can be noted and
         recorded. The position of the ]@PD is reflected by change in
         sediment color form brown to black. Each core should be
         homogenized for analysis, but the replicates should be treated as
         distinct samples and not pooled prior to analysis.

         Benthic infauna samples may be collected either by a diver using
         a core sampler having an area of at least  0.01 M2 or by a grab or
         box corer having an area of at least 0.1  M2 . The same stations
         sampled for sediment chemistry (0, 20, 50, 100 and 200 feet from
         the net-pens) should be sampled for benthic infauna. Three
         replicate samples should be collected at each site. The same
         grab/box corer samples used for sediment chemistry should be used
         for benthic infaunal analysis provided no more than one-quarter
         of the surface of each sample has been removed for sediment
         chemisrty sampling. Each benthic infauna sample should be sieved
         on a 0.5 mm screen or nested 1.0 and 0.5 mm screens. All


                                         78









        macrofaunal organisms retained on the screen(s) should be
        identified to the lowest practical taxonomic level, generally
        species.

        The results of the baseline benthic survey should be assembled in
        a report consistent with the report guidelines provided for the
        site characterization survey and the annual monitoring. The
        baseline report should be submitted to BMR, who will take
        responsibility for distribution to other agencies for comment and
        action.























































                                       79











         Appendix C. Annual Monitoring.

         Upon issuance of a state lease and State and Federal permits a
         monitoring program will be required. The annual monitoring
         program is designed to serve two purposes. First, it is intended
         to monitor potential changes in water and sediment quality
         resulting from culture activities. Secondly, it provides data
         with which to review the current environmental requirements for
         possible future modifications. As additional data are obtained
         on the environmental effects of net-pen or'on- or off-bottom
         shellfish culture, the annual monitoring protocol may be
         substantially revised. It is also possible that monitoring at
         some culture sites may be curtailed or eliminated entirely if
         little or no measurable effect on environmental quality is found
         after several years of operation. The determination to curtail
         or eliminate monitoring at any site will be made after BMR review
         of survey results.

         The annual monitoring program consists of three principal
         elements:


               (1) a benthic survey, including diver observations and
                    sampling of sediments and benthic infauna;
               (2) water quality sampling; and
               (3) a hydrographic survey.

         Class I facilities should be exempted from annual monitoring.
         Class II net-pen fish culture facilities and on- and off-bottom
         shellfish culture facilities should be required to conduct only a
         diver survey.

         The potential for water quality impacts related to net pen fish
         culture will be directly related to the amount of feed used on
         the farm. The annual monitoring requirements have been designed
         to require more extensive monitoring for farms using larger
         quantities of feed.



         FEED USE CATEGORIES.

         Three categories of monitoring have been established based on
         annual feed usage. As each category has different monitoring
         requirements, the first step is to identify the correct
         monitoring schedule for each level of operation. Each permit
         holding facility is considered to be a separate farm and must  be
         reported independently.

         Estimate the total dry weight of fish feed to be used in the
         ensuing calendar year on the farm site. Although this feed will
         normally be in the form of wet feed (or silage), moist feed, or
         dry feed, total feed should be calculated in terms of dry weight

                                         80









        only. Note that the amount of dry feed is not equivalent to dry
        weight. Dry weight of feed can usually be determined by
        referring to the feed manufacturer's product specifications.
        These specifications should include the moisture content of the
        feed. This content can then be subtracted from the total weight
        of the feed to yield total dry weight. If moisture content
        specifications are not provided by the feed supplier or
        manufacturer, it is the responsibility of the farmer to make this
        determination. Percent moisture is defined as the percent loss
        in weight of feed when dried to a constant weight at a
        temperature of 105 degrees Celsius.

        For example, if annual feed requirements for a net pen fish farm
        are:
             _ 500 metric tons dry feed with 10% moisture content
             - 80 metric tons moist feed with 35% moisture content
             - and 50 tons wet feed with 70% moisture content,
        then the total feed usage in terms of dry weight will be:
                   = (500 - 10%) + (80   35%) + (50 - 70t)
                   = (500 - 50) + (80   28) + (50 - 35)
                   = 450 + 52 + 15
                   = 517 metric tons dry weight

        If the total dry weight of feed is less than 120 metric tons (mt,
        1 metric ton = 2200 lbs), only a minimum of record keeping
        information is required. If the total dry weight of feed is
        between 120 mt and 630 mt inclusive, additional requirements for
        basic oceanographic data and a diver survey of bottom sediments
        will be needed. Farms using in excess of 630 mt dry weight of
        feed annually are subject to the most intensive monitoring.
        Table A2 shows the farm category associated with each feed use
        category.


                           TABLE A2.   Farm Categories.



               Dry Weight  of Feed                 Farm Category
                   (metric tons)

                       < 120                              1

                     120 - 630

                       > 630



        BENTHIC SURVEY


        The benthic survey is intended to assess the extent of solids
        accumulation on the bottom in the vicinity of the culture


                                         81









          operation and the biological effect of this accumulation. The
          survey consists of diver observations and sampling of sediment
          chemistry and benthic infauna. Diver observations are required
          if any portion of the sea bottom within 300 feet of the site is
          at a water depth of 75 feet or less. Documenting the diver
          survey with either continuous video footage or with photographs
          taken at 20-foot intervals may be required. A brief narrative
          with the tape or photos describing reference points should also
          be included. All documentation must include the dates on which
          it was taken.

          Four transects, each at least 20'0 feet in length, should be
          established as illustrated in Figure A2. The transects should be
          extended if feed or feces accumulation is visible 200 feet from
          the pens. Additional transects may be required to survey
          habitats or resources of special concern. Divers will not be
          required to operate in depths greater than 75 feet.

          A diver survey shall be conducted twice a year, between January
          and February and again between August and September. One of the
          principal objectives of the diver survey is to document the depth
          and lateral extent of solids accumulation. The diver should
          estimate the depth of feed and feces accumulation at 20-foot
          intervals along each transect, and should note the greatest
          distance from the net-pens that visible accumulation is present.
          The diver should also note the presence/absence of Beggiatoa mats
          and estimate densities of demersal fish, crabs and other
          invertebrates.


          The annual monitoring benthic survey for Class III operations
          will also include collection of sediment and benthic infauna
          samples. The station location and sampling protocol should be
          exactly as described in the baseline benthic survey (Appendix B).
          Benthic monitoring will be required during the first period of
          peak feeding. This will generally coincide with the first
          harvest at the end of the growing season. After this monitoring
          will occur at the peak feeding period every year, except for
          semi-annual diver surveys.

          a.    Sediments. Sediment  cores are to be analyzed for sediment
          grain size (% gravel, sand, silt, clay); the- depth of the redox
          discontinuity layer, the depth of the unconsolidated organic
          layer and TOC. Plexiglas type corer is to be used. Single core
          samples collected according to the approved sampling plan must be
          inserted to 4 inches. The depth of the discontinuity layer and
          the depth of the unconsolidate&organic layer are to be measured
          from the surface.


          Grain size analyses should be performed using the Wet Seiving
          method. The standard sieve sizes for gravel, sand, silt and clay
          are to be used. Full analyses of the silt-clay fractions may be
          calculated as the difference in'dry weight between the original

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                               mmmm=MM==












                                                                  200 ft

                                                                 (1, more

                                                                                            NET-PEN SITE


                                                                                                           200 If

                                                                                                          ormore











                                                      TRANSECTS
















                                     Figure A2
                                                              DIVER TRANsi.,crS DURING THE ANNIJAI, MONITORING SURVEY










        sample and the sum of the sieve fractions down to the 0.062 mm.
        sieve (very fine sand). The fraction in each sieve should be
        reported in grams (dry weight) and percent of total (dry weight)
        including the total dry weight of the initial sample. The
        unconsolidated material and the top 2 cm of inorganic sediments
        shall be collected for the analysis of TOC. The applicant must
        insure that a minimum of 30 grams are collected for analysis.
        Multiple cores (which include the top 2 cm of inorganic material)
        if warranted, will be required. Total Organic Carbon should be
        analyzed using established methods.

        b. Infauna. Benthic infauna samples may be collected either by
        a diver using a core sampler having an area of at least   0.01m2
                                                                   2
        or by a grab or box corer having an area of at least 0. 1 m . The
        same stations sampled for sediment chemistry (0, 20, 50, 100 and
        200 feet from the net-pens) should be sampled for benthic
        infauna. Cores should be taken during the season of maximum
        feeding. Three replicate samples should be collected at each
        site. The same grab/box corer samples used for sediment
        chemistry should be used for benthic infaunal analysis provided
        no more than one-quarter of the surface of each sample has been
        removed for sediment chemistry sampling. Each benthic infauna
        sample should be sieved on a 0.5 mm screen or nested 1.0 and 0.5
        mm. screens. All macrofaunal organisms retained on the screen(s)
        should be identified to the lowest practical taxonomic level,
        generally species.


        WATER QUALITY SURVEY

        Water quality sampling is intended to document the effect of
        culture activity on dissolved oxygen and nutrients in the water
        passing through the culture structure. The survey should be
        conducted every two weeks from June to September, inclusive, of
        each year that the facility is in operation. Sampling during the
        summer and early fall months is recommended since it is during
        this period that dissolved oxygen reductions or nutrient
        enrichment are of greatest concern. Three stations should be
        sampled: 100 feet upcurrent of the net-pens; 20 feet downcurrent;
        and 100 feet downcurrent. The precise location of the stations
        will depend on net-pen configuration, but they should be located
        so as to monitor the water passing through the greatest possible
        number of net-pens. Sampling should be conducted within one hour
        of slack tide. Three replicates should be taken at each station
        at a depth mid-way between the water surface and the bottom of
        the net-pens. Samples should be analyzed for the following
        parameters: dissolved oxygen; temperature; salinity; pH; ammonia;
        and nitrite/nitrate (either separate or combined). The
        concentration of unionized ammonia should also be calculated.

        Also, during the peak feeding period a one-time detailed analysis
        of dissolved oxygen, temperature and salinity will be prepared

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          for each station, consisting of 10 equally-spaced samples over
          the entire vertical depth of the station.

          Water samples may be collected or an electronic membrane probe
          may be used to measure the concentrations. Temperature and
          salinity measurements should be used to determine percent
          saturation of dissolved oxygen and stratification. Although the
          preferred method is the "Winkler Titration" (Azide modification),
          described in Standard Methods , the use of the membrane electrode
          method is acceptable, provided recommended procedures are
          followed. If the membrane probe method is used, appropriate
          verification procedures (described in Appendix A) must be used.

          HYDROGRAPHIC SURVEY


          Current velocity and direction should be measured at the depth at
          which the water quality samples are taken. A single measurement
          should be made 20 feet downcurrent of the net-pens concurrently
          with-collection of the water quality sample from this station.
          Loading estimates (g/kg fish/day) should be calculated for
          ammonia and nitrite/nitrate based on:

               (1) the net increase in concentration between the upcurrent
               station and the 20 foot downcurrent station;
               (2) the current velocity 20 feet downcurrent;
               (3) the cross-sectional area of the net-pen complex; and
               (4) the weight of fish on hand at the time of the water
               quality survey.

          REPORT PREPARATION


          The comments made regarding the site characterization report
          apply here as well. Specifically, analysis and interpretation of
          the data should be provided, not merely presentation of the raw
          data. However, the raw data should be provided in appendices so
          as to permit independent assessment of conclusions.

          In addition to a description of methods and data analysis and
          interpretation, the annual monitoring report should also include
          information on operational practices over the past year. This
          information should include:

               1) General description of facility (species cultured, size
                    at which fish will be marketed, etc.).

               2) Size, number and configuration of net-pens at time of
                    sampling.

               3) Significant changes in size, number and configuration of
                    net-pens over the previous year.



                                          84









             4) Annual production (live weight, pounds) cumulative to
                  the end of the reporting period.

             5)  Estimated weight of fish on hand during survey (pounds).
             6)  Stocking density (average and range, lbs/ ft3).

             7)  Type of feed used, percent moisture, quantity used of
                  each type and feeding method employed.

             8)  Types of antibiotics used, amount, date, form
                  administered over the past year.

             9)  Interactions with birds and marine mammals and a summary
                  of types and frequency of predator control measures
                  used.

             10)  Types of antifoulants employed and frequency of net
                  treatment, net cleaning. List all materials directly
                  or indirectly released to the water (anesthetics,
                  cleaners, pigments, hormone treated feed etc.), date,
                  amount and how they were applied.

             11)  Waste disposal. Indicate methods used to dispose of
                  dead fish and any processing wastes generated on site.
                  Give dates, quantities involved and names of any
                  contractors used.

             12)  Provide an estimate of projected feed usage for the
                  upcoming year, based on production plans.


        The annual monitoring report should be submitted to BMR within 30
        days of the end of the reporting period set by the agency. The
        BMR take responsibility for distribution to other appropriate
        authorities.






















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