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





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               The Zooplankton of the Little Manatee River Estuary, Florida.
                                  First Yearly Report: 1988








                             Jonathan Rast and Thomas L. Hopkins
                   Department of Marine Science, University of South Florida









            Funding for this project was provided by the Florida Department of
            Environmental Regulation, Office of Coastal Management using funds made
            available through the National Oceanic and Atmospheric Administration under
            the Coastal Zone Management Act of 1972, as amm nded. Local administration of
            this work was conducted through contracts with the Southwest Florida Water
            Management District; project manager, Michael S. Flannery.
















                  The Zooplankton of the Little Manatee River Estuary, Florida.
                                    First Yearly Report: 1988









                               Jonathan Rast and Thomas L. Hopkins
                     Department of Marine Science, University of South Florida










              Funding for this project was provided by the Florida Department of
              Environmental Regulation, Office of Coastal Management using funds made
              available through the National Oceanic and Atmospheric Administration under
              the Coastal Zone Management Act of 1972, as ammended. Local administration of
              this work was conducted through contracts with the Southwest Florida Water
              Management District; project manager, Michael S. Flannery.













                                                 TABLE OF CONTENTS


                                                                                            Page No


                EXECUTIVE SUMMARY . . . . . . . . ... . . . . . . . .. . . . ..  . . . . . .        i
                INTRODUCTION  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .           1


                METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . .          2


                SOURCES OF BIAS*                                               . . . . . . .        3


                RESULTS AND DISCUSSION   . . . . . . . . . . . . . . . . . . . . . . . . .          4


                CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .           13


                REFERENCES CITED  . . . . . . . .      . . . . . . . . . . . . . . . . . .          15













                                              EXECUTIVE SUMMARY



                    Zooplankton were collected bi-weekly from the Little Manatee River Estuary
               for a period of one year from January 1988 through January 1989. Six stations
               were sampled: a control placed approximately 2 miles out of the mouth of the
               river into the bay, and five stations spaced at roughly 2-mile intervals within
               the river beginning at the mouth. Collections were made at night during
               incoming tides. At each station, samples of 44 liters were taken by even ly
               spacing four 11 liter niskin bottle casts throughout the water column. The
               water was then passed through a 0.028 mm sieve in order to capture all multi-
               cellular animals present. Abundances for each organism identified were
               calculated as number per cubic meter. Dominant organisms were placed into size
               categories which were used to estimate biomass from previously calculated
               length-weight regressions. Salinity, temperature and dissolved oxygen were also
               measured at each station.
                    Sixty-seven groups of zooplankton were identified. Dominants (those groups
               making up more than 1% of total abundance at any station) included copepod
               crustaceans, polychaete worm larvae, rotifers, mollusk larvae and crab larvae.
               The diversity and abundance of the zooplankton in the bay were greater than in
               the fresh and brackish water regions of the river. Average abundance and
               biomass within the river was 143,000/m3 and 46.9 mg/m3 compared to bay values of
               351,000/M3 and 175 mg/m3. As a result, the abundance of zooplankton in the
               river tended to be positively correlated with salinity and was low during
               periods of high rainfall when the bay water was excluded from the river. A
               number of freshwater crustaceans and rotifers were found at the upper stations
               during periods of high flow, however, their abundance was usually low in
               comparison to the higher salinity-fauna. The larvae of copepod crustaceans were
               the most abundant plankter at all stations and often contributed the greatest
               biomass. The small mesh used (about one half the size of the smallest size
               usually used in this type of study) demonstrates a much higher contribution from
               these small plankters than usually reported. The zooplankton of the bay
               included a higher percentage contribution from the larvae of benthic
               invertebrates (6.31%) than that of the river (3.90%), as is expected from the
               greater number of benthic invertebrates found there.
                    A number of studies have demonstrated that most of the dominant species
               found in this survey serve as food for larval and juvenile fish. Larval fish
               abundance, however, showed little relationship to zooplankton abundance so other
               fish food items must be important, particularly in low salinity areas. Since
               fish larvae were collected simultaneously with zooplankton, planned work on the
               gut contents of these fish will serve to clarify the relative importance of
               zooplankton in supporting fish production in the Little Manatee River.









               The Zooplankton of the Little Manatee River Estuary, Florida.


               Objectives

                   The Little Manatee River zooplankton survey  is part of an ongoing
               multidisciplinary study which addresses physical and chemical parameters, and
               the distribution of phytoplankton, ichthyoplankton, and juvenile and adult
               fish within the river. Since the Little Manatee river is, as yet, only
               moderately encroached upon by man, a study of this area may serve both as a
               comparison for the more impacted tributaries of Tampa Bay, and as background
               information for subsequent research as the watershed is further developed.
               Zooplankton and ichthyoplankton were sampled simultaneously so that the
               trophic relationship between the two groups could be addressed.

               Related Studies


                   Although the distribution of zooplankton species on the west coast of
               Florida has been addressed by a number of authors, most studies are either
               lacking in seasonal data or deal with areas of higher salinities than those
               measured in the Little Manatee River. Davis (1950) gives a good general
               account of speciei composition in Florida waters, but gives no seasonal
               information and mainly deals with areas of higher salinity than those found in
               the Little Manatee River. King (1950) presents taxonomic data on a variety of
               locations along the Florida west coast. Two of his stations are similar to
               the Little Manatee River in salinity structure and fresh water flow conditions
               (the Caloosahatchie River near Fort Myers and the Peace River near Punta
               Gorda), but no seasonal information is given. Grice (1956) reports on the
               seasonality of Copepoda observed in weekly samples taken at Alligator Harbor,
               but salinities there (26-31 ppt.) were much higher than those seen in the
               Little Manatee River. Davis and Williams (1958) present an informative
               account of species distribution in mangrove areas in southern Florida.
               Salinity regimes in the areas studied are similar to those found in the Little
               Manatee River, but seasonal information is lacking. Hopkins (1966) gives a
               comprehensive treatment of the zooplankton of the St. Andrew Bay system, but
               in contrast to the Little Manatee River, this area tends to be more saline
               with much advection of truly marine species from the Gulf. It is therefore
               difficult to make comparisons. Studies that lend themselves to comparison
               include Hopkins (1977), Weiss (1978) and Squires (1984). Hopkins (1977)
               presents seasonal information on zooplankton of Tampa Bay, however, resolution
               is limited as samples were taken quarterly. Although stations were sampled
               within the.Little Manatee River, these results were not published. Weiss
               (1978) and Squires (1984) present data that is similar to the present study
               from the Anclote estuary and Charlotte Harbor, respectively.

               The Little Manatee River


                    Lewis and Estevez (1988) give a good general account of the ecology of
               Tampa Bay and include the following information about the River. The Little
               Manatee River is located on the eastern shore of Tampa Bay at latitude 27*40'
               N and longitude 82* 30' W, draining an area of approximately 211 square miles
               in Hillsborough and Manatee counties. Discharge, averaged over the year, is









                estimated to be near 235 cubic feet per second, making it the smallest of
                Tampa Bay's four major tributaries. Tidal influence extends 15 miles (24km)
                upriver. The Littl-e Manatee River is considered the least impacted of Tampa
                Bay's rivers, with only 2.7% of its watershed urbanized. It also has the
                lowest phosphorous and organic nitrogen concentrations and carries the least
                .amount of oxygen demanding material. The Little Manatee River is thus well
                suited for a background study of zooplankton distribution and seasonality in a
                tributary to Tampa Bay.



                METHODS


                     Station placement and sampling times coincided with those of the
                ichthyoplankton survey. Six stations were sampled semimonthly from January
                1988 through January 1989. Five of the stations were distributed within the
                Little Manatee River at roughly two mile intervals beginning with station 1
                approximately one mile upriver from the 1-75 overpass and ending at the river
                mouth with station 5 (see map, Fig la). River mile designations for stations
                1 through five are as follows: 1, 8.8; 2, 6.4; 3, 4.4; 4, 2.2; 5, 0.0. A
                sixth station which served as a control was placed 2.2 miles into Tampa bay,
                outside of the river's direct influence except during periods of very high
                flow. Samples were taken at night, usually between the hours of 7:00pm and
                1:00am, on an incoming tide. Stations were divided into upper and lower river
                sets of three and sampled on two successive nights in order to remain in phase
                with the tides. Water was collected with an 11 liter Niskin bottle. At each
                station four 44 liter samples were taken: two samples integrating the water
                column, one surface and one bottom sample. During the first five collections,
                reduced volumes of 33 liter and on rare occasions 22 liters were sieved at
                times when clogging made sieving greater volumes impossible. Integrated
                samples were taken by evenly spacing four bottle casts between the surface and
                approximately 20 cm above the sediment. Two replicate integrated samples were
                taken at each station approximately 500m apart, one at each end of the
                ichtyoplankton.tow area. Surface samples were taken from the upper meter of
                the water column, and bottom samples within the one meter zone standing.20 cm
                over the bottom. Samples were placed in a holding vessel and sieved through a
                Nitex mesh. Sieves were used in place of plankton nets in order to avoid
                problems of quantification resulting from the clogging of small mesh nets. In
                collections one through five an 11 um mesh was used. As this was prone to
                clogging, however, mesh size was increased to 28 um in subsequent collections.
                Sieving experiments from the larger to smaller mesh showed that there was no
                significant loss of metazoans from the 28 um fraction. Samples were preserved
                immediately upon collection in 3-5 percent formalin buffered with sodium
                borate.
                     Temperature, salinity and dissolved oxygen were also measured at each
                station. Readings were taken at 0.5 meter intervals from surface to bottom.
                     Zooplankton samples were split in a Motoda box (Motoda 1959) until an
                aliquot containing approximately 1500 individuals was obtained. Samples were
                then placed in ruled petri dishes. Smaller plankters (<0.3mm) were counted at
                50X, and larger ones at 25X. At least 100 specimens of each dominant taxon
                were counted. In cases where it was not necessary to count the entire tray,
                diagonals were counted to avoid bias resulting from clumping generated by
                currents within the tray. Most holoplanktonic animals were identified to

                                                      2









                species. Meroplankton (those plankters found in the water column     for only a
                portion of their lifecycle), tychoplankton (benthic animals swept    off the
                bottom by currents)-and hypoplankton (benthic animals which swim off the
                bottom only for a limited period of time) were identified only to major group.

                     For each sample analyzed, twenty-five individuals from each taxon were
                measured and placed into one of three group specific size classes (two size
                classes were used for species with low size variation). Size class data were
                then used to estimate biomass from length:weight regressions presented in
                Weiss (1978). These regressions were either empirically determined by
                weighing a number of organisms of a specific size class on microscope
                coverslips, taken from those determined for similar organisms, or estimated
                from geometric volume calculations.
                     Zooplankton densities were often compared with salinity distribution. To
                test for correlations a nonparametric Spearman's coefficient of rank
                correlation (r,) was used, as density distributions did not lend themselves to
                parametric statistics.



                SOURCES OF BIAS


                     Bias in the data can be divided into two categories: that from the
                sampling procedure and timing (field procedure), and that introduced in the
                process of sample splitting and counting (laboratory procedures). Discussion
                of the latter is found in Weiss (1978). Briefly, variability of counting was
                found to be independent of taxon and to depend solely on density within the
                sample.   A curve of coefficient of variation among replicate countings
                plotted against number of zooplankters counted, shows that variation for
                dominant zooplankters (about 50-100 individuals counted per sample) fell     in to
                the 20-30% range while those for total zooplankton counted (500-1000
                individuals) were close to 10%.
                     Variation over the diel and tidal cycle was not investigated as all
                sampling was done at similar times and tidal conditions. Weiss (1978) sampled
                over an entire tidal cycle at two times during the year and found the
                coefficient of variation of the dominant holoplanktonic and meroplanktonic
                species in single samples to average 37% in September when abundances were
                high and 61% in December at lower overall abundances. These numbers,
                however, also reflect variation resulting from day/night migrations and
                watermass movements. Minello et al. (1981) in a study of diel zooplankton
                variation in a northwestern Gulf of Mexico estuary, found counting and
                subsampling error to be insignificant when compared to replicate tow
                variability, and this in turn insignificant compared to variability over the
                diel cycle. Although tidal and light cycles could not be separated in this
                study, it was suspected that diel vertical migration contributed greatly to
                variation. Diel vertical variation in abundance of species which were
                dominant in the Little Manatee river was seen by Fult   on (1984) in estuaries
                near Beaufort, North Carolina. &carti tonsa,.Parvocalanus crassirostris and
                Pseudodiaptomus coronatus tended to remain on or towards the bottom during the
                day. This should not present a problem in the present study, however, as
                these species were more uniformly distributed throughout the water column at
                night. Fulton found copepod nauplii and Oithona spp. were uniformly
                distributed at all times. Omori and Hamner (1982), however, have observed

                                                        3









                 swarming in Oithona, Acartia and Labidocera in a     ssociation with grassbeds,
                 coral heads and shallow embayments.
                       Although horiz -ontal variability cannot be separated from error inherent
                 in the sampling procedure itself, as only two replicates were taken, the upper
                 end of this variation can be bracketed as less than or equal to variation
                 between replicates. Replicate samples were taken approximately 250m apart.
                 Mean coefficients of variation (essentially range/ mean in a two sample
                 situation) for the each replicate set (n-144) was determined for four
                 representative groups of taxa: copepod nauplii (44.86%),'polychaete larvae
                 (75.28%), adult and copepodid Acartia tonsa (56.96%), and total zooplankton
                 counts (7.3%). Coefficients of variation between replicates were inversely
                 proportional to relative abundance for the more specific groups observed
                 (i.e., excluding total zooplankton).
                       Bias in sampling procedure also includes that introduced by mesh size
                 and water volume sampled. As a 28 um sieve was used minimal loss of smaller
                 metazoans is expected. Relative to most previous zooplankton studies using
                 64-74 um mesh, however, a significant increase in the proportion of
                 microzooplankton captured is probable. Hopkins (1977) found that a 64 um
                 sieve retains 69% of the metazoans caught on a 28 um mesh. Most loss
                 consisted of copepod nauplii and pelecypod larvae. Due to the small size of
                 the zooplankton that passed through the 64 um sieve, only 6% of the biomass
                 was lost. Precision of density determinations of plankters on the upper end
                 of the size scale was often limited by their low numbers. As larger
                 zooplankters are usually found at low densities, accurate estimations of
                 abundance from counts made on a 44 liter samples, to the degree that this was
                 possible for the smaller, more abundant zooplankters, could not be made.


                 Table  1. Sampling Dates.

                 Coll.  No./ Dates          Coll. No./ Date          Coll.  No./ Dates

                   1.   1/29-30/88             9. 5/25-26/88          17.   9/ 26-27/88
                   2.   2/10-11/88           10.  6/ 8-9 /88          18.   10/11-12/88
                   3.   2/23-24/88           11.  6/27-28/88          19.   10/25-26/88
                   4.   3/ 3-4 /88           12.  7/11-12/88          20.   11/14-15/88
                   5.   3/23-24/88           13.  7/25-26/88          21.   11/28-29/88
                   6.   4/ 6-7 /88           14.  8/ 9-10/88          22.   12/13-14/88
                   7.   4/25-26/88           15.  8/24-25/88          23.   12/26-27/88
                   8.   5/11-12/88           16.  9/12-13/88          24.   l/ 16-17/88




                 RESULTS AND DISCUSSION


                 Hydrographic Data

                       All temperature, salinity and dissolved oxygen readings are given as
                 water column averages. Water temperature (Fig. 2) in the Little Manatee River
                 ranged from a low in January at collection 1 of 12.8*C to a high of 32.0*C in
                 August. Greatest temperature variation among stations was seen in the months
                 of July and August, but differences never exceeded PC during any given

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               collection. Temperatures recorded at the river stations tended to be cooler
               than those of the bay.
                    Salinity rarely varied greatly throughout the water column as depths
               within the river usually did not exceed 2 m and vertical mixing was
               significant. Salinity in the river (Fig. 1) ranged from a low of 0 ppt that
               was often seen at stations 1-3 and on two occasions at station 4, to a high of
               30 ppt at the river mouth during collection 10 in June. Maximum salinity at
               station 6 in Tampa Bay was 33.5 ppt during collection 14 in August. Maximum
               salinity range from station 1 to the river mouth was 0.4 ppt to 24.0 ppt
               during collection I in January. Two major drops in salinity were observed,
               one beginning from a high at collection 1 and dropping to a low throughout
               February and March, and a second beginning towards the end of July and
               dropping to a low at extending from July through September.
                    Dissolved oxygen (Fig. 3) ranged from a low of 2.3 ppm at station 1 in
               July to a high of 11 ppm at the same station in October. More typical highs
               ranged up to about 9 ppm, however. Readings were generally below 4 ppm from
               July through September.    Dissolved oxygen at the bay station followed the
               general trend seen in the river yet remained more stable. Dissolved oxygen
               showed a strong negative correlation with temperature (r,=-0.8038, p<0.001).
                    Flow rates in the Little Manatee River (Fig. 4) varied from a low of
               approximately 15 cf/s in June to a peak of 9720 cf/s after four days of
               unusually heavy rainfall in September. Flow was at increased levels during
               the period from July to the end of August. Other high flow levels were seen
               in February, early March, and after tropical storm Keith in November. Periods
               of low flow occurred from November to January and most notably during the
               period of drought from April through June.

               ZOOPLANKTON

                    Zooplankton taxa were classified  in 67 categories (Table 2). In most
               cases, holoplankton.were identified to species. Exceptions include freshwater
               copepods in the family Cyclopidae, Calanoids in the genus Diaptomus and
               rotifers. In all, 29 groups of holoplankton were identified. Meroplankton
               and tychoplankton/ hypoplankton were identified only to major group (e.g.,
               crab zoea, pelecypod larvae, etc.). Meroplankton and tychoplankton/
               hypoplankton were placed in 26 and 12 groups, respectively.
                    Abundance rankings for zooplankton taxonomic groups were created
               excluding station 6 which was used as a control to compare the fauna of the
               river to that of Tampa Bay (Table 3). A breakdown of dominants for each of
               the five river stations is given in Table 4. Taxonomic groupings were
               arbitrarily placed into three classes according to their average contribution
               to overall abundance within the river. Plankters making up more than 1.0% by
               number were classified as dominants, those contributing between 1.0% and 0.1%
               were considered subdominants, and those constituting less than 0.1% of total
               numbers are classed as uncommon. Six taxonomic categories are included under
               the classification of dominant: copepod nauplii (81.5%), Oithona colcarva
               (6.0%), Acartia tonsa (3.9%), benthic harpacticoid copepods (1.8%), polychaete
               larvae (1.7%) and rotifers (1.1%). Q. colcarv , A. tonsa and benthic
               harpacticoids undoubtedly contributed greatly to copepod nauplii numbers, but,
               as nauplii were not identified to species, their relative contributions cannot
               be quantified. Taken together these dominant make up approximately 96.0% of
               total plankton numbers and 86.4% of the calculated biomass within the river.








                         Subdominants include nine groupings contributing 2.93% of total density
                  and 7.89% of total biomass in the river. Eurytemora hirundoides,
                  PseudodiaRtOmus coronatus, and Oikiopleura dioica, although not large
                  contributors in terms of numbers, ranked fifth, sixth and seventh in biomass
                  contributions because of their relatively large size.





                  Table 3. Relative contributions to total abundance and biomass at stations
                  within the Little Manatee river (stations 1-5); numbers in parentheses are
                  from station 6, within Tampa Bay.

                  Category            Species/ Group                % Abundance        % Biomass

                  Dominant          Copepod nauplii                  81.5  (53.9)    28.7  (9.1)
                                    Oithona colcarva                 6.0   (21.5)    11.4  (28.6)
                                    Acartia tonsa                    3.9   (3.9)     31.4  (25.2)
                                    Benthic Harpacticoids            1.8   (0.2)     14.0  (1.9)
                                    Polychaete Larvae                1.7   (7.45     0.88  (4.7)
                                    Rotifera                         1.1   (0.1)     0.08  (0.01)
                  Subdominants      Pelecypod Larvae                 0.95  (2.1)     0.25  (0.64)
                                    Barnacle nauplii                 0.52  (0.76)    0.10  (0.14)
                                    Eurytemora hirundoides           0.36  (0.00)    1.58  (0.01)
                                    PseudodiARtomus coronatus        0.31  (0.89)    2.58  (3.8)
                                    Oikiopleura dioica               0.21. (1.1)     1.63  (3.9)
                                    Parvocalanus crassirostris       0.18  (3.4)     0.34  (4.2)
                                    Gastropod Larvae                 0.17  (0.47)    0.29  (0.57)
                                    Euterpina acutifrons             0.13  (0.85)    0.90  (5.1)
                                    SaRhirella spp.                  0.10  (0.45)    0.22  (0.63)







                  Table 4. Abundance      and biomass of dominants by station averaged over the year.
                  Taxa with asterisks formed >1% of biomass, but did not fall into the dominant
                  category in terms of abundance at that station.

                  Taxonomic Group                   Abundance (perc.)        Biomass (perc.)
                                                    Number/M3                mg DW/m 3
                  STATION 1 (Mile     8.8)

                  Copepod nauplii                   23600  (72.2%)           2.83 (29.1%)
                  Rotifera                            4310 (13.2%)           0.10 (1.04%)
                  Eurytemora hirundoides              1480 (4.53%)           2.58 (26.3%)
                  Benthic Harpacticoida               1240 (3.80%)           3.02 (30.7%)
                  Pelecypod larvae                    596  (1.82%)           0.027(0.28%)
                  Polychaete larvae                   522  (1.60%)           0.106(l.09%)
                  Decapod zoea*                       16.5(0.05%)            0.230(2.40%)


                                                                   6










                Table 4. (cont.)

                STATION 2 (Mile   6.4)

                Copepod nauplii                77000 (82.8%)         9.33  (29.7%)
                Benthic Harpacticoida          4060  (4.36%)         12.6  (40.1%)
                Rotifera                       2980  (3.20%)         0.07  (0.22%)
                Acartia tonsa                  2820  (3.03%)         4.58  (14.6%)
                Polychaete larvae              1900  (2.04%)         0.29  (0.93%)
                Pelecypod larvae               1250  (1.35%)         0.09  (0.29%)
                Decapod zoea*                  57.6  (0.06%)         2.63  (8.37%)


                STATION 3 (Mile 4.4)

                Copepod nauplii               141000 (88.5%)         18.8  (39.8%)
                Acartia tonsa                  5460  (3.43%)         13.6  (28.9%)
                Benthic Harpacticoida          5400  (3.42%)         11.2  (23.7%)
                Oithona colcarva               2310  (1.45%)         1.39  (2.94%)
                Polychaete larvae              1880  (1.18%)         0.26  (0.56%)
                Decapod zoea*                  56.7  (0.04%)         1.10  (2.34%)


                STATION 4 (mile 2.2)

                Copepod nauplii               158000 (87.8%)         17.2  (35.8%)
                Acartia tonsa                  8030  (5.45%)         20.1  (41.7%)
                Oithona colcarva               6710  (3.72%)         3.73  (7.73%)
                Polychaete larvae              2970  (1.65%)         0.39  (0.81%)
                Benthic Harpacticoida*         1090  (0.61%)         2.48  (5.15%)
                OikioRleura dioica*             457  (0.25%)         0.66  (1.38%)
                Decapod zoea*                   97.8(0.05%)          1.25  (2.59%)


                STATION 5 (River Mouth)

                Copepod nauplii              182000 (73.2%)          19.0 (19.5%)
                Oithona colcarva              33100 (13.3%)          21.3 (21.9%)
                Acarti tonsa                   11700 (4.71%)          35.1 (36.0%)
                Polychaete larvae              4660  (1.88%)         1.02  (1.05%)
                Pelecypod larvae               3800  (1.53%)         0.34  (0.35%)
                Pseudodiaptomus coronatus      2010  (0.81%)         5.64  (5.80%)
                OikioRleura ALoicA*            1050  (0.42%)         3.16  (3.24%)
                Benthic Harpacticoida*          889  (0.36%)         3.37  (3.46%)
                EuterRina acutifrons*           780  (0.31%)         1.74  (1.79%)
                Decapod zoea*                   276  (0.11%)         1.97  (2.02%)







                                                           7










                 Table 4. (cont.)

                 STATION 6 (Bay)

                 Copepod nauplii             189000 (53  -9%         16.0 (9.12%)
                 Oithona colcarva               75600 (21.5%)         50.0 (28.6%)
                 Polychaete  larvae            26100 (7.43%)         8.34  (4.76%)
                 Acartia tonsa                 14000 (3.98%)         441.1 (25.2%)
                 Parvocalanus crassirostris    12000 (3.43%)         7.52  (4.29%)
                 Pelecypod larvae               7580 (2.16%)         1.13  (0.64%)
                 OikioRleura dioica             4070 (1.16%)         6.83  (3.90%)
                 Pseudodia2t0mus coronatus*     3110 (0.89%)         6.74  (3.85%)
                 EuterRina acutifrons*          2980 (0.85%)         9.08  (5.18%)
                 Benthic Harpacticoida*           909 (0.26%)        3.35  (1.92%)
                 Decapod zoea*                    675 (0.19%)        6.10  (3.48%)
                 Barnacle cyprids*               436 (0.12%)         2.35  (1.35%)
                 Sagitt tenuis*                   254 (0.07%)         2.10 (1.20%)


                 Dominant Zooplankters

                 1. Copepod nauplii. (Fig. 5) Numerically, copepod nauplii were by fa       r the
                 mos't abundant zooplankton and were second only to Acartia tonsa in biomass.
                 Proportionally, nauplii were of greater importance within the river (81%) than
                                                                                  e              we
                 at the Bay station (53%). In terms of absolute numbers, how       ver, nauplii      re
                 on average more abundant at the Tampa Bay station: 189,000/m vs. 116,000/m
                 in the river stations. Naupliar abundance was found to be considerably higher
                 in this study than that seen by Hopkins (1977; a mean of 26,644/M3       for the Mid
                 .Tampa Bay area). In regards to biomass contribution, these two studies are
                 also disparate: 2.36 mg/m3 in Hopkins (1977) vs. 15.98 Mg/M3. As Hopkins used
                 a 74 um mesh, a number of smaller nauplii were probably lost that were
                 captured in the 28 um mesh used in the present study. In a study of the
                 Anclote estuary by Weiss (1978) using 64 um mesh, naupliar abundances,
                 although still less than those found at the bay station, are comparable to
                 those seen in the present study (between 97370-131014/m     3 at stations of
                                                                              3
                 similar salinities). Biomass ranged from 6.18-6.63 mg/m , much less than the
                 15.98 Mg/M3 calculated at station 6. Squires (1984), in a study of the
                 Charlotte harbor area using 70um mesh, found copepod nauplii densities at
                 station 2 (the station most similar in salinity structure to the Tampa Bay
                 station in the present study) of 127,741/m3 with a biomass of 12.17 Mg/M3.
                 None of the above mentioned studies included stations that were comparable        to
                 the river stations as salinity fluctuations within the river were much greater
                 than those seen in the Tampa Bay, Anclote estuary or Charlotte Harbor.
                 Nauplii abundance was positively correlated to salinity in the river
                 (r.-O.6854, p<0.001). This is expected as much of the copepod density within
                 the river was the result of importation from the high salinity, high abundance
                 waters of the bay.
                      Copepod nauplii abundance seemed to be inversely related to flow within
                 the river. This was, no doubt, both the result of dilution at high flow rates
                 and exclusion of the high density bay waters from the river. At any one time,
                 naupliar abundance was usually lower in the upriver stations, probably the
                 result of the lower overall copepod abundances there.

                                                            8










                 2. Oithona colcarva.   (Fig. 6)  In terms of biomass, the cyclopoid copepod
                 g.colcarva is ranked  fourth within the river and first at the Bay station,
                 contributing 11.38%- (5.3 mg/m3) and 28.55% (50.0 Mg/M3) on average,
                 respectively. Numerically, this cyclopoid ranked second within both the river
                 and the bay contributing on average 5.96% (8500/m    3) and 21.54% (75,6   OO/M3).
                 Hopkins (1977) found a density of 11,496/m   3 for 0. colcarva at the Mid Bay
                 station and a whole bay average biomass of 7.92 mg/m    3.  Weiss (1978) found a
                 density range of 13,117-16,474/m  3 and a biomass range of 5.02-7.15 mg/m    3  in
                 the Anclote estuary. In Charlotte Harbor Squires (1984) found densities more
                 similar to those at station 6 in the present study: 56,66     9/M3 and 30.64 Mg/M3.
                   colcarva density was positively correlated with salinity (r.=0.8532,
                 p<0.001).
                      Oithona colcarva is a bay species that is only found within the river
                 during periods of low flow and high salinity. Abundances were low at the
                 upper stations. In eight of the collections, 0. colcarva was absent from all
                 three upper stations and in only one collection was it found at station 1.

                 3. Acartia tonsa. (Fig. 7) Within the Little Manatee River, the calanoid
                 copepod A. tons contributed 3.93% of the zooplankters by number, ranking it
                 third, and 31.4% of the biomass, ranking it first. In absolute terms, A.
                 tonsa averaged 5613/m 3 and 14.72 mg/m  3within the river. At the bay station
                 averages were 13,900/m 3  (4.0%) and 44.12 Mg/M3 (25.18%). As with other taxa,
                 abundance values for A. tonsa found by Hopkins (1977) in the middle Tampa Bay
                 region (2278/m 3) were much lower than those seen at the bay station. Hopkins
                 did-note, however, that densities at the mouth of the Manatee River were much
                 higher, indicating the possibility that the bay station in the present study
                 was not entirely out of the influence of the river. Weiss (1978), at a
                 station in the Anclote River system of similar salinity structure to our bay
                 station, found comparable densities (13,400/M3    ; 22.57 Mg/M3).   In Charlotte
                 Harbor, Squires (1984) also found similar densities (8,069/m3; 26.27 mg/m3).
                    tons density was positively correlated with salinity (rs-0.6656, p<0.001).
                      Acartia tonsa exhibited A similar distributional pattern to that of
                 Oithona colcarva, yet was found at lower salinities and was therefore at
                 greater abundances at the upper river stations and during periods of high
                 flow.


                 4. Benthic Harpacticoid Copepods. (Fig. 8) Harpacticoid copepods, excluding
                 EuteKRina acutifrons and Miracia sp. which are holoplanktonic, ranked fourth
                 in both relative density (1.78%) and biomass (14.0%) within the river
                 (2552/m3; 6.55 Mg/M3). At the bay station densities were much lower: 93       l/M3
                 (0.26%), 3.39 mg/m3 (1.9%). Because harpacticoids are important mainly within
                 the river at lower salinities, comparisons to Charlotte Harbor and the Anclote
                 estuary cannot be made as hydrographically similar areas were not investigated
                 in these studies. Comparisons of the bay station to stations of similar
                 salinity showed that in the Anclote estuary numbers and biomass were similar,
                 but were lower in Charlotte Harbor. No significant correlation was found
                 between density and salinity, due at least in part to the fact that this
                 category is made up of a group of species having differing salinity
                 tolerances.
                      This group exhibited relatively stable densities throughout the year,
                 especially at the lower stations. The upper stations were more variable than
                 the lower, probably a result of the increased influence of.freshwater flow










                 variation there *  In all, this group was less affected by flow within the
                 river than the previous three dominants, probably as a result of their benthic
                 nature and consequent partial independence from the water column.

                 5. Polychaete Larvae. (Fig. 10)    Polychaetes were the most numerous component
                 of the meroplankton, and ranked fifth and tenth, respectively, in terms of
                 density (2386/m 3; 1.7%) and biomass (0.42 mg/m  3; 0.88%) in the river. At
                 station 6 in the bay numbers were much higher (26,100/m    3; 8.34 mg/m 3) . These
                 numbers are much higher than those found in Tampa Bay by Hopkins (1977) and in
                 the Anclote estuary by Weiss'(1978), but are close to those seen in Charlotte
                 Harbor (18,809/M3 ) by Squires (1984). Polychaete numbers were positively
                 correlated with salinity (r.-O.7445, p<0.001).
                      Polychaete larvae, being essentially marine also tended to drop in
                 abundance both at times of high flow and at the upriver stations. A decrease
                 in abundance at successive upriver stations was not as clear as that
                 demonstrated by a true bay species (e.g., Oithona colcarva) indicating some
                 degree of production within the river.

                 6. Rotifera. (Fig. 9) Although of little importance in terms of biomass,
                 rotifers were at times numerically significant, especially at the upriver
                 stations. Average density and biomass were 1637/m3     and 0.04 Mg/M3 within    the
                 river. Rotifers were not identified but common genera included Trichocerca,
                 Proales and Keratella at stations with higher salinities. Brachionus, Lecane,
                 Monostyla and Platyias were common at lower salinity stations within the
                 river.
                      Rotifer abundance increased and became more stable moving from the bay
                 station to station 1. Abundances tended to decrease with increasing flow
                 probably as the result of dilution, This group, like the polychaete larvae
                 and the benthic harpacticoids, consists of a number of species of greatly
                 differing salinity tolerances, thus obscuring patterns of distribution evident
                 in monospecific analyses.


                 Subdominant Zooplankters

                      Nine categories of zooplank  ton contributed between 0.1% and 1.0% to total
                 abundance within the river and were thus classed as subdominants. Five of
                 these, Pseudodiaptomus coronatus, OikiopleurA dioica, Parvocalanus
                 crassirostris, EuterRina acutifrons. and Saphirella spp., were members of the
                 higher salinity bay fauna that entered the river in diluted densities during
                 periods of low flow.
                      Pseudodiaptomus coronatus (Fig. 11) was found in salinities ranging from
                 18 to 34 ppt.        is a relatively large species and, although it contributed
                 relatively little in term of numbers (448/m   3, 0.31%), it ranked fifth in
                 contribution to biomass within the river (1.21 mg/m   3, 2.58%). Considerably
                 higher abundance and biomass was seen at the bay station (3    110/M3 , 6.73
                 mg/m 3). Much lower abundances were seen in Hopkins (1977) study of Tampa Bay,
                 Charlotte Harbor (Squires 1984) and the Anclote estuary (Weiss 1978). This is
                 probably in part due to the epibenthic nature of this species during the day
                 (Jacobs 1968), as the above studies involved daytime surface collections.
                      Parvocalanus crassirostris (Fig. 12) was an abundant copepod within        the
                 bay contributing 3.4% (12  'OOO/M3) of the abundance at the bay station, making

                                                         10









               it the thi rd most abundant copepod there. Within the river, however, it was
               of less importance as it was rarely found at salinities lower than 18 ppt.
               Densities within the river averaged 263/m3 and biomass 0.16 mg/m 3.
                    EuterRina acutifrons (Fig. 13), was also relatively abundant within the
               bay, but was rare within the river and rare at salinities lower than 15 ppt.
               Average abundance and biomass within the river were 190/m 3and 2.1 mg/m 3.
                    OikioRleur dioica (Fig. 14) was present mainly in salinities higher
               than 18 ppt. At station 6, this species averaged 4070/m 3 and 6.8 Mg/M3.
               Within the river averages were 301/M3 and 0.76 Mg/M3. No larvaceans were
               found upriver from station 4. These numbers are similar to those found by
               Hopkins in Tampa Bay and Weiss in the Anclote Estuary, but were much lower
               than those seen by Squires in Charlotte Harbor.
                    SaRhirella spp. (Fig. 15) abundance was positively correlated to
               salinity (r.-O.6610, p<0.001) and although it was found at all stations, its
               numbers were sharply reduced at lower salinities. At least two species were
               collected. Abundance and biomass within the river and the bay averaged 146/m  3
               (0.10 mg/m3) and 1580/m3 (1.10 Mg/M3) , respectively.
                    Eurytemor hirundoides (Fig. 16) is a brackish water copepod that was
               often very abundant at upper river stations, mainly between salinities of 1-10
                                                                                        3
               ppt. This species made a significant contribution to biomass (0.74 mg/m
               1.58%) within the river and often dominated samples taken at the upper
               stations. The nauplii of E. hirundoides are large and were at times abundant
               at stations 1-3. This was the only calanoid copepod that was present in
               significant numbers at low salinities.
                    Pelecypod and gastropod veligers were at times abundant within the river
               and often showed trends related to freshwater flow regimes. Pelecypod larvae
               (Fig. 17) were especially abundant at times of higher salinity and showed a
               pattern of abundance from station to station indicative of import from the
               higher salinities of the bay. Gastropod veligers (Fig. 18) demonstrated a
               similar trend, although, somewhat less clearly. Average densities and
               biomasses for the river stations were, for bivalves, 1350/m3 (0.11 Mg/M3 ) and
               for gastropods, 249/m3 (0.13 Mg/M3).
                    Barnacle nauplii (Fig. 19) within the river averaged 744/m and 0.05
               mg/m3, about an order of magnitude lower than densities at the bay station.
               At the upper stations, density patterns are related to salinity trends (i.e.,
               present at times of higher salinity) indicating importation from the higher
               salinity lower stations. Densities at the lower river stations, however, show
               a patchy distribution indicative of some degree of localized production.

               Uncommon Zooplankters

                    At times, species not considered dominant or subdominant were found at
               significant densities. Most notable among these were the cladocerans Evadne
               tergestina, Podon Rolyphemoides and Penilia avirostris. In 24 of the 288
               samples taken one of these species was found at densities in excess of
               1000/M3. These cladocera are essentially bay species that were important
               within the river only at periods of high salinity.
                    Other uncommon zooplankters occasionally found at high densities include
               amphipods, decapod zoea, and polyclad flatworms. Stations where these
               plankters occurred and time of year are listed in Table 5.













                TOTAL ZOOPLANKTON


                     The abundance--and biomass yearly averages for each category of
                zooplankton at each station are given in Table 6. Total zooplankton density
                and biomass averaged throughout the year within the river were 143,000/m 3 and
                46.9 mg/m3. These were considerably lower than the average density and
                biomass seen at the Tampa Bay station of 351,000/m 3 and 175 mg/m3. Broken
                down into plankton type, numerically the catch averaged for the five river
                stations was 94.0% holoplankton, 3.90% meroplankton and 2.10i
                tycho/hypoplankton. Biomass percentages were 79.6%, 6.31% and 14.1%,
                respectively. Bay station densities were 87.7% holoplankton, 11.8%
                meroplankton and 0.44% Tycho/hypoplankton. Biomass ratios for these plankton
                categories in the bay were 85.0%, 12.9% and 2.10%, respectively. Thus, the
                bay had higher numbers of meroplanktonic organisms as would be expected from
                the higher diversity of the benthic invertebrate fauna found there. The
                river's higher percentage of tychoplankton is probably the result of scouring
                during periods of high flow. Tychoplankton peaks at stations 1 and 2 during
                May and at station 3 during July represent high abundances of benthic
                harpacticoid copepods.
                     Total zooplankton seasonal fluctuations in both density and biomass are
                shown in Fig. 20. From a seasonal.perspective, total zooplankton biomass at
                the bay station wa's at a low at collection 2 in February and peaked at
                collection 9 in May. The river stations generally reflected this pattern with
                modification during periods of high flow. For example, collection 16 in
                September was a lowpoint at all five river stations as a result of anomalously
                high flowrates after a period of high rainfall. Seasonal fluctuations of
                zooplankton density and biomass averaged over the five river stations is given
                in Figure 21.
                     Zooplankton numbers and especially biomass decreased from station 6 in
                the bay to station 1. 'This is essentially the result of a dilution of the
                higher biomass, high salinity bay waters by the low biomass freshwater of the
                river. A number of the dominant and subdominant species were characterized by
                an inverse relationship between abundance and distance upriver. These include
                0. colcarva, A. tonsa, polychaete larvae, Pseudodiaptomus coronatus,
                OikioRleura dioica, Parvocalanus crassirostris, Euterpina acutifrons, and to a
                lesser extent, bivalve and gastropod veligers and barnacle nauplii. Species
                which are bay fauna and show little or no production within the river are
                characterized by a pattern of strict reduction in density from station to
                station moving upriver. These include Oithona colcarva and Parvocalanus
                crassirostris. Some taxonomic groups exhibited abundances not correlated with
                distance up river at stations of higher salinity and progressively reduced
                numbers at the upper stations where salinities were very low. These include
                polychaete larvae, barnacle nauplii and to some extent SaRhirella. This is
                most likely the result of some degree of production or concentration taking
                place within the river at the higher salinity, lower stations, combined with
                increasing dilution as at the upper stations.
                     Most zooplankton groups show an inverse relationship between flow and
                abundance. For the higher salinity bay fauna, this is most likely the result
                exclusion from the river by flow. For the freshwater fauna, however, lower
                densities are probably the result of dilution as rainfall increases river
                volume at a rate that cannot be compensated for by zooplankton reproduction.


                                                      12









                     As the river is in a constant state of flux, with salinity regimes moving
                up and down it in response to rainfall and tides, a spatial community
                structure is difficult to define. The holoplankton Are made up of the bay and
                true freshwater river fauna with very few species playing an intermediate role
                (Eurytemora and Halicycjops are in this group). Within the bay fauna,
                differing abilities to penetrate the lower salinity waters of the river are
                evident (see Table 5). For example, Acartia, Oithona, PseudodiaRtomus, and
                Parvocalanus, in that order, show a decreasing penetration into the river.

                CONCLUSIONS


                     The lower section of the Little Manatee that was the focus of this study
                is a transition zone between the freshwater fauna of the river proper and that
                of Tampa Bay. Because each station is part of a continuum between very
                different environments and as this zone actually moves under different flow
                regimes, it is difficult not only to generalize among stations, but also to
                compare at a given station among collections. Station was used as the hub of
                interpretation in this study (as opposed to salinity, for example) because
                sampling strategies were centered on the stations (equal effort at each
                station), and because some plankters such as polychaete and bivalve larvae are
                tied to the benthos and therefore to a stationary area within the river.
                Averages among the river stations, therefore, are valuable only as an
                indication of the relative importance of the different groups and say very
                little about abundance at any one place within the river. An average      for
                different stations in Tampa Bay, for-example, is likely to be a more
                reasonable estimate of abundance at any one spot within the bay than a river
                average which, depending on the species of concern, is likely to represent
                merely a dilution of a more concentrated abundance at either the high or low
                salinity end of the sampling zone. Averages are used only in the interest of
                briefness, and the graphs of abundance vs. collection give a more realistic
                interpretation of densities.
                     Two aspects of the present study are unique among similar investigations
                made along the west coast of Florida: samples were taken at night and mesh
                size was considerably smaller than those used previously. The combination of
                these two factors probably accounts for most of the increase in numbers seen
                at the bay station as opposed to similar stations in nearby studies (Hopkins
                1977, Weiss 1978, Squires 1984). A number of papers describe diel vertical
                migration for many of the dominant copepods seen in the Little Manatee River
                (Fulton 1984; Jacobs 1961, 1968; Hamner 1982). With the exception of Oithona
                and copepod nauplii Fulton (1984) describes all of the dominant copepods in
                the present study as either bottom oriented or surface avoiding during the
                day. As Hopkins (1977), Weiss 1978, and Squires (1984) all sampled at the
                surface during the day their numbers are expected to show lower abundances.
                     The 28 um mesh employed in this study is considerably smaller than those
                used by Hopkins (1977), Weiss (1978) and Squires (1984) who used mesh sizes
                ranging from 64 um to 74 um. Turner (1982) comments on the overwhelming
                abundance of copepod nauplii taken with a 73 um mesh that was not seen with
                larger mesh sizes. It is likely that even a 73 um mesh, which is smaller than
                that used in most zooplankton studies, lets a significant number of nauplii
                pass through. Hopkins (1977) reports a 31% loss in numbers from a 64 um to a
                28 um mesh. As these were mainly copepod nauplii and bivalve larvae, biomass
                loss was only 6%, but, in cases where copepod nauplii are of interest (e.g.,

                                                        13









                as food for fish larvae) an underestimate caused by too large a mesh size may
                be significant. Conley and Turner (in review) point out that nauplii may be
                an important link between the primary production by nanoplankton and larger
                zooplankton and icfithyoplankton that feed on the nauplii. While it is
                generally assumed that these athecate nanoplankters are too small to be fed
                upon by larger zooplankton, copepod nauplii may be able to take advantage of
                this resource.
                    The role of zooplankton as food for larval and postlarval fishes in an
                Newport River estuary, N.C. is addressed by KJelson and Johnson (1976) who
                describe the impact of postlarval Lagodo rhomboides and Leiostomus xanthurus
                on Acartia tonsa. L. rhomboides having a mean weight 25 mg was found to
                ingest an average of 92 copepods per day, and L. xanthurus having a mean
                weight of 42 mg, 115 copepods per day. Thayer et al. (1974), also in the
                Newport estuary, find thatlarval L. rhomboides and Brevortia tyrannus feed on
                Acartia, Centrogages, EuterRina and Temora, and that the abundance of these
                zooplankters may be critical to the survival of these fishes during their
                larval-postlarval transition. Stickney et.al. (1975) investigated the diets
                of young sciaenids and found copepods to be an important component, especially
                Pseudodiaptomus coronatus and benthic harpacticoids. Leiostomus xanthurus was
                found to select for copepods at all growth stages. These studies indicate
                that planktonic crustacea are important mainly in the diets of larval and
                postlarval fishes and that juveniles tend to select larger benthic organisms.
                Mysids were important in the diets of juvenile sciaenids and were mentioned as
                predators of copepods by Fulton (1984). Mysids may thus serve as a link
                between zooplankton and bottom feeding fish that are too large to feed on
                copepods. Gut content studies on the larval, postlarval and juvenile fishes
                of the Little Manatee River would be the next step in defining the trophic
                relationship between them and the zooplankton found there.
                    The accuracy of abundance estimates in this study depend on the
                assumption that zooplankton densities found in the river channel are
                representative of those in other areas of the river (i.e., that these are
                relatively passive organisms that tend to be randomly distributed). There is
                mounting evidence for both behavioral and physical patchiness for most of the
                dominant species found in the Little Manatee River. Therefore to truly
                examine the importance of zooplankton within the river, some smaller scale
                studies should be made to determine the variation over different habitats
                found there. For monitoring purposes, however, examination of channel
                zooplankton only may be adequate. Little long-term monitoring has been done
                in this area and as the variation in physical parameters and plankton
                patchiness make data interpretation (i.e., elucidating causal relations
                between plankton numbers and the physical/biological factors within the
                river), it would be valuable to continue sampling in the future.











                                                     14












              REFERENCES CITED



              Conley, W.J. and J.T. Turner. Phytoplankton and zooplankton of the Westport
                 River estuary, Massachusetts. In review.

              Davis, C.C. 1950. Observations of plankton taken in marine waters of.Florida
                 in 1947 and 1948. Quart. J. Florida Acad. Sci. 12:67-103.

              Davis, C.C. and R.H. Williams. 1950. Brackish water plankton of mangrove areas
                 in southern Florida. Ecol. 31: 519-531.


              Fulton, R.S. 1984. Distribution and community structure of esturine copepods.
                 Estuaries. 7:38-50.


              Hopkins, T.L. 1966. The plankton of the St. Andrew Bay system, Florida. Ph.D.
                 Dissertation, Florida St. Univ. 97 pp.

              Hopkins, T.L. 1977. Zooplankton distribution in the surface waters of Tampa
                 Bay, Florida. Bull. Mar. Res. 27:467-478.

              Grice, G.d. 1956. A qualitative and quantitative seasonal study of the
                 Copepoda of Alligator Harbor. Florida State U. Stud. No. 22. Papers from
                 the Oceanogr. Inst. No. 2. 37-76.

              Jacobs, J. 1961. Laboratory cultivation of the marine copepod PseudodiaRtOmus
                 coronatus Williams. Limnol. Oc.eanogr. 6: 443-446.

              Jacobs, J. 1968. Animal behavior and water movement as determinants of
                 plankton distribution in a tidal system. Sarsia. 34:355-370.

              Kjelson, M.A. and G.N. Johnson. 1976. Further observations on  the feeding
                 ecology of postlarval pinfish, Lazodon rhomboides, and spot, Leiostomds
                 xanthurus. U.S. fish. Wildl. Serv. Fish. Bull. 74:423-432.


              Minello, T.J. and G.A. Matthews. 1981. Variability of zooplankton tows in a
                 shallow estuary. Contr. Mar. Sci. 24:81-92.

              Motoda, S. 1959. Devices of simple plankton apparatus. Mem. Fac. Fish.,
                 Hokkaido Univ. 7:73-94.


              Lewis R.R. and E.D. Esteves.. 1988. The ecology of Tampa Bay, Florida- an
                 esturine profile. U.S. Fish Wildl. Serv. Biol. Rep. 85(7.18). 132 pp.

              Squires, A.P. 1984. Thedistribution and ecology of zooplankton in Charlotte
                 Harbor, Florida. Master's Thesis. 60 pp.

              Stickney, R.R., G.L. Taylor, and D.B. White. 1975. Food habits of young
                 southeastern United States esturine Sciaenidae. Chesapeake Sci. 16: 104-
                 114.





                                                    15









                Thayer, G.W., D.E. Hoss, M 'A. Kjelson, W.F. Hettler,Jr. and W.M. LaCroix.
                   1974. Biomass of zooplankton in the Newport River estuary and the
                   influence of postlarval fishes. Chesapeake Sci. 15: 9-16.

                Turner, J.T. 1982. The annual cycle of zooplankton in a long  island estuary.
                   Estuaries. 5:261-274.


                Weiss, W.R. 1978. The zooplankton of the Anclote estuary, Florida. Master's
                   Thesis. Univ. S. Florida. 122 pp.



                TAXONOMIC REFERENCES


                Bowman, T.E. 1971. The distribution of  calanoid copepods off the southeastern
                   United States between Cape Hatteras  and southern Florida. Smithsonian
                   Contr. Zool. 96:1-58.


                Bowman, T.E. 1975. Oithon colcarva   n. sp., an American copepod incorrectly
                   known as 0. brevicornis (Cyclopoida: Oithonidae). Chesapeake Science,
                   16(l):134-137.

                Davis, C.C. 1943. The larval stages of the Calanoid copepod Eurytemor
                   hirundoides (Nordquist). Chesapeake Biol. Lab. Publ. No. 58. 52 pp.

                Ferrari, F.D. and T.E. Bowman. 1980. Pelagic copepods of the family Oithonidae
                   (Cyclopoida) from the east coast of Central and South America. Smithsonian
                   Contr. Zool. 312.


                Grice, G.D. 1960. Calanoid and Cyclopoid copepods collected from the Florida
                   Gulf coast and Florida Keys in 1954 and 1955. Bull. Mar. Sci. Gulf Carib.
                   10(2):217-226.

                Crice, G.D. 1960. Copepods of the genus Oithona from the Gulf of Mexico. Bull.
                   Mar. Sci. Gulf Carib. 10(4):485-490.

                Essenberg, C. 1926. Copelata from the San Diego region. University of
                   California Publications in Zoology, 28:399-521.

                Owre, H.B. and M. Foyo. 1967. Copepods of the Florida Current. Fauna Caribaea
                   No. 1.


                Pennak, R.W. 1953. Fresh Water Invertebrates of the United States. The Ronald
                   Press Company. New York.

                Smith, D. L. 1977. A Guide to Coastal Marine Plankton and Invertebrate Larvae.
                   Kendall Hunt Publishing Co. Iowa.

                Wilson, C.B. 1932. The COReRods of the Woodshole Regio , Massachusetts. Bull.
                   U.S. Nat. Mus., 158:635pp.

                Yamaji, Isamu. 1966. Illustrations of the Marine Plankton of JaRan. Hoikusha
                   Publishing Co., Ltd. Osaka, Japan.

                                                       16









                        Table 2. Abundance (number/m    3   by station for year 1. mean; median (range).


                                                           STATION I          STATION 2           STATION 3           STATION 4          STATION 5           STATION 6
                                                           (mile 8.8)         (mile 6.4)          (mile 4.4)          (mile 2.2)         (River Mouth)       (Bay)


                        HOLOPLANKTON


                        Hydromedusae                           ----           1.62; 0             2.71; 0             4.12; 0            26.6; 0             208; 0
                                                                              (0-52)              (0-52)              (0-52)             (0-207)             (0-2050)
                        Cladocera
                            Unidentified                   60.6; 0            21.0; 0             8.10; 0             8.08; 0            3.25; 0                  ----
                                                           (0-310)            (0-207)             (0-103)             (0-103)            (0-52)
                            Podon ootyphemoides                ----                ----                ----           36.8;'0            65.5; 0             550; 0
                                                                                                                      (0-1030)           (0-1240)            (0-10300)
                            Evadne teruestina                  ....                ....           1.08; 0             73.5; 0            52.6; 0             1490; 0
                                                                                                  (0-52)              (0-2340)           (0-547)             (0-28400)
                            Penitia avirostris                 ----                ....                ....           45.5; 0            87.9; 0             1030; 0
                                                                                                                        (0-1520)            (0-2190)            (0-15400)
                        Copepoda
                            NaupHi                         23600; 9140        77000; 43800        141000; 115000      158000; 117000     182000; 157000      189000; 133000
                                                           (52-314000)        (103-316000)        (258-704000)        (387-6510001)      (15000-826000)      (10200-733000)
                            Calanoidai
                            Acprtia Tonsa                  60.1; 0            2820; 13            2310; 142           8030; 654          .11700; 3460        14000; 9920
                                                           (0-1100)           (0-36200)           (0-58770)           (0-90800)          (0-66400)           (1100-64600)
                            Eurytemora hirundoides         1480; 672          688; 142            359; 0              64.8; 0            7.52; 0             2.88; 0
                                                           (0-9300)           (0-12800)           (0-10500)           (0-1080)           (0-206)             (0-138)
                            Tortanus setacaudatus              ----                ----                ----           0.542; 0                ---- 6.10; 0
                                                                                                                      (0-26)                                 (0-155)
                            ParvocaLanus crassirostris         ----                ----           33.0; 0             320; 0             963; 258            12000; 6790
                                                                                                  (0-724)             (0-3720)           (0-10900)           (155-70100)
                            Centropages hamatus                ----                ....                ----                ----               ....           9.67; 0
                                                                                                                                                             (0-464)
                            Djaptomus spp.                 16.6; 0            5.96; 0             7.54; 0             8.60; 0            5.40; 0                  ----
                                                           (0-52)             (0-310)             (0-258)             (0-103)            (0-129)
                            Pseudodiaptomus coronatus      1.62; 0            10.8; 0             15.1; 0             201; 0             2010; 284           3110; 878
                                                           (0-52)             (0-310)             (0-258)             (0-3100)           (0-18600)           (0-22900)











                      Table 2. (continued) Abundance (number/m      3   by station for year 1. mean; median (range).


                                                         STATION I           STATION 2          STATION 3           STATION 4           STATION 5          STATION 6
                                                         (mile 5.8)          (mite 6.4)         (mite 4.4)          (mite 2.2)          (River Mouth)      (Bay)


                          Labidocera aestiva                  ----               ----           2.17; 0                  ----           1.08; 0            94.4; 0
                                                                                                (0-52)                                  (0-52)             (0-826)
                          Temora turbinata                    ....               ----                ----                ----           10.8; 0            79.4; 0
                                                                                                                                        (0-207)            (0-820)
                        Cyctopoida
                          Unidentified Cyciopidae        59.8; 0             22.6; 0            17.2; 0             16.7; 0             8.60; 0                  ----
                                                         (0-362)             (0-207)            (0-155)             (0-207)             (0-207)
                          Oithona coicarva               1.08; 0             365; 0             2310; 52            6710; 513           33100; 17400       75600; 51900
                                                         (0-52)              (0-3720)           (0-16900)           (0-55900)           (0-216000)         (2790-301000)
                          Olthona nana                   0.542;  0           1.44; 0            12.8; 0             24.1; 0             41.8; 0            204; 0
                                                         (0-26)              (0-69)             (0-276)             (0-413)             (0-615)            (0-1840)
                          Oithona simptex                     ....           1.08; 0            6.46; 0             14.5; 0             55.6; 0            131; 0
                                                                             (0-26)             (0-155)             (0-413)             (0-2200)           (0-1240)
                          Haticyctops sp.                45.4; 0             2.71; 0            1.08; 0             4.33; 0             23.2; 0                  ----
                                                         (0-482)             (0-52)             (0-52)              0-52)               (0-547)
                          Nesocyctops edax               6.50; 0                 ----           1.08; 0             2.17; 0                  ----                ----
                                                         (0-104)                                (0-26)              (0-104)
                          Sag)hiretta spp.               1.62; 0             61.0; 0            97.6; 0             146; 13             422; 129           1580; 482
                                                         (0-52)              (0-671)            (0-1030)            (0-2326)            (0-2790)           (0-8260)
                          ErgasiLidae                    20.8; 0             21.0; 0            27.9; 0             23.9; 0             20.3; 0            8.62; 0
                                                         (0-413)             (0-207)            (0-207)             (0-258)             (0-414)            (0-207)
                        Harpacticoida
                          Euterpina acutifrons                ----           5.76; 0            7.90; 0             106; 0              780; 0             2980; 516
                                                                             (0-2760)           (0-155)             (0-1240)            (0-16300)          (0-25800)
                          Miracia sp.                         ----           0.542; 0                                    ----                ----
                                                                             (0-26)
                      Decapoda
                          Lucifer faxoni                                         ----                 ----               ----           6.46; 0            12.8; 0
                                                                                                                                        (0-207)            (0-410)
                       Larvacea
                          Oikiopieura dioica                  ----               ----                 ----          457- 0              1050; 13           4070; 2000
                                                                                                                    (0-;0700)           (0-15300)          (0-30700)









                       Tabie 2. (continued) Abundance (number/m      3  by station for year 1. mean; median (range).


                                                         STATION 1           STATION 2           STATION 3          STATION 4           STATION 5           STATION 6
                                                         (mite 8.8)          (miLe 6.4)          (miLe 4.4),        (mite 2.2)          (River Mouth)       (Bay)


                       Chaetognatha
                          Unidentified                        ....           0.542; 0                ----           18.3; 0             66.0; 0             124; 0
                                                                             (0-26)                                 (0-310)             (0-1450)            (0-1230)
                          Saoitta hispida                     ----                ----               ....                ----           15.1; 0             29.9; 0
                                                                                                                                        (0-414)             (0-820)
                          Sagitta  tenuis                     ....                ----           1.62; 0            0.542; 0            44.6; 0             254; 0
                                                                                                 (0-52)             (0-26)              (0-723)             (0-2480)

                       MEROPLANKTON
                       Nemertea                          5.40; 0                  ----               ----                ----                 ----
                                                         (0-207)
                       PoLycLadida                            ....           222; 0              148; 0             55.4; 0             43.7; 0             170; 0
                                                                             (0-5580)            (0-6400)           (1650)              (0-1140)            (0-2460)
                       Cercaria                                                                      ----           0.542; 0                  ----
                                                                                                                    (0-26)

                       AnneHda
                         Otigochaeta                     120; 0              23.7; 0            .17.2; 0            2.69;   0           0.542; 0                 ----
                                                         (0-826)             (0-361)             (0-206)            (0-77)              (0-26)
                         PoLychaeta                      522; 52             1900; 388           1880; 1420         2971;   1420        4660; 2270          26100; 7750
                                                         (0-8540)            (0-25200)           (0-9090)           (0-19loo)           (0-27000)           (0-393000)
                       Motiusca
                         Gastropod   Larvae              18.7; 0             179; 0              124; 26            165; 78             759; 0              1650; 826
                                                         (0-439)             (0-1910)            (0-1140)           (0-1650)            (0-7650)            (0-12300)
                         Petecypod   Larvae              596; 0              1250- 0             629; 13            466; 78             3800; 542           7580; 2840
                                                         (0-11300)           (0-9;20)            (0-5990)           (0-3310)            (0-37500)           (0-114000)
                       Cirripedia
                         NaupHi                          96.7; 0             748; 30             444; 181           496; 1%             1940; 413           2660; 1650
                                                         (0-964)             (0-5970)            (0-2480)           (0-2270)            (0-13400)           (0-14700)
                         Cypris                          11.5; 0             3.42; 0             5.04; 0            24.8; 0             122; 0              436; 0
                                                         (0-413)             (0-138)             (0-52)             (0-362)             (0-1500)            (0-6612)
                       Stomatopod Larvae                      ----                ----               ----                ----                 ----          4.31; 0
                                                                                                                                                            (0-207)










                       Table 2. (continued) Abundance (number/m      3   by station for year 1. mean; median (range).



                                                          STATION I          STATION 2           STATION 3           STATION 4          STATION 5           STATION 6
                                                          (mite 8.8)         (mite 6.4)          (mite 4.4)          (mite 2.2)         (River Mouth)       (Bay)


                       Decapoda
                         Zoea                             16.5; 0            57.6; 0             56.7; 0             99.8; 0            276; 0              675; 155
                                                          (0-275)            (0-775)             (0-517)             (0-1030)           (0-4130)            (0-4304)
                         Megalopa                             ----           1.44; 0             3.06; 0             1.08; 0            36.1; 0             12.8; 0
                                                                             (0-69)              (0-69)              (0-26)             (0-620)             (0-410)
                         Mysis-zoea                           ----           1.62; 0                  ----           6.48; 0            6.47; 0             32.3; 0
                                                                             (0-52)                                  (0-77)             (0-103)             (0-826)
                       Insecta
                         Dipteran Larvae                  89.7; 52           41.5; 0             19.1; 0             11.8; 0                 ----
                                                          (0-361)            (0-258)             (0-104)             (0-155)
                         Dipteran Pupae                       ....           1.08; 0             0.542; 0                ----                ----                 ....
                                                                             (0-52)              (0-26)
                         Ephimoptera Larvae               3.23; 0            1.08; 0                  ----               ----                ....                 ----
                                                          (0-155)            (0-52)
                         Odonate                          4.88; 0            1.62; 0                  ----               ----                ----                 ....
                                                          (0-52)             (0-52)
                       Bipinnaria                             ----                ----                ----               ----                ----           150; 0
                                                                                                                                                            (0-3690)
                       Opheopluteus                           ....                ----                ....               ----           56.0; 0             553; 0
                                                                                                                                        (0-2270)            (0-6760)
                       Tornaria                               ----                ----                ----           1.08; 0            30.1; 0             390; 0
                                                                                                                     (0-52)             (0-930)             (0-5780)
                       Actinotrocha                           ----                ----                ----               ----                ----           8.62; 0
                                                                                                                                                            (0-207)
                       Cyphonauta                             ----                ----                ----           2.15; 0            4.83; 0             15.8; 0
                                                                                                                     (0-103)            (0-103)             (0-413)
                       Ascidiacea   (tadpole Larvae)          ----                ----                ....               ----           6.46; 0             4.31; 0
                                                                                                                                        (0-310)             (0-207)
                       CephLochordata                         ----                ----                ----           5.94; 0            327; 0              623; 0
                                                                                                                     (0-103)            (0-9300)            (0-12300)



















                                                                        3
                        TabLe 2. (continued) Abundance (number/m            by station for year 1. mean; median (range).



                                                            STATION 1            STATION 2           STATION 3            STATION 4            STATION 5           STATION 6
                                                            (miLe 8.8)           (miLe 6.4)          (miLe 4.4)           (miLe 2.2)           (River Mouth)       (Bay)


                        Pisces Egg                          2.88; 0              181; 0              2.15; 0              31.6; 0              1610; 0             314; 0
                                                            (0-138)              (0-7379)            (0-103)              (O-MO)               (0-73800)           (0-5990)
                        Pisces Larvae                       4.83; 0                    ----          3.23; 0              1.62; 0              806; 0              1880; 0
                                                            (0-129)                                  (0-103)              (0-52)               (0-37700)           (0-413)
                        TYCHOPLANKTON/ HYPOPLANKTON
                        Nematoda                            54.5; 0              38.2; 0             101; 0               24.3; 0              78.5; 0             34.8; 0
                                                            (0-773)              (0-206)             (0-3620)             (0-104)              (0-732)             (0-413)
                        Hydrazoan cotony fragments               ----            1.62; 0                  ----                  ----           1.08; 0             7.19; 0
                                                                                 (0-52)                                                        (0-26)              (0-207)
                        Acarina                             5.42; 0              2.69; 0             363; 0               1.08; 0                   ....           9.33; 0
                                                            (0-52)               (0-77)              (0-17110)            (0-52)                                   (0-207)
                        Ostracoda                           139; 52,             77.4; 26            8.6; 0               23.2; 0              36.2; 0             225; 0
                                                            (0-689)              (0-516)             (0-465)              (0-775)              (0-723)             (0-2460)
                        Harpactacoida (benthic)
                          Unidentifed                       1200; 310            4060; 904           5440; 736            1090; 774            889; 671            909; 414
                                                            (0-12300)            (0-55300)           (0-129000)           (0-4180)             (0-4650)            (0-5320)
                          Parateaasres spericus                  ----                  ----1         2.15; 0              8.27; 0              22.6; 0             12.8; 0
                                                                                                     (0-103)              (0-138)              (0-412)             (0-410)
                          Metis spp.                             ----                  ----               ----            1.08; 0                   ----           8.62; 0
                                                                                                                          (0-52)                                   (0-207)
                        Isopoda                             3.23; 0              16.7; 0             7356; 0              15.3; 0              69.5; 0             77.3; 0
                                                            (0-77)               (0-517)             (0-103)              (0-207)              (0-547)             (0-820)
                        Amphipoda                           74.4; 0              154; 0              139; 0               17.5; 0              21.2; 0             12.6; 0
                                                            (0-826)              (0-2070)            (0-4490)             (0-207)              (0-310)             (0-207)
                       ,Cumacea                                  ----            2.88; 0                  ----            5.94; 0              27.2; 0             4.85; 0
                                                                                 (0-69)                                   (0-103)              (0-275)             (0-103)
                        Mysidacea                           17.8; 0              15.1; 0             18.3; 0              27.1; 0              105; 0              58.8; 0
                                                            (0-517)              (0-206)             (0-362)              (0-310)              (0-1640)            (0-1230)
                        Tardigrada                          1.62; 0              3.23; 0                  ----                  ----                ----                 ----
                                                            (0-26)               (0-155)













                        Table 5. Uncommon (<0.1% total numbers) species seasonal distribution. 24 samplings broken into 12 monthly sets of 2 collections
                                  each. 1-6 indicates stations where present. * >100 percubic meter, ** >500 per cubic meter.


                                                             1         2          3          4         5          6         7         a          9         10         11        12


                        HOLOPLANKTON


                        Hydromedusae                                   6*         3-6        5         56*        26**      36                   6**      3*5*6       46        456


                        Unidentified   CLadocera             12        1*2*34     12345                                     145       23         1*23       1*         1*23


                        Podon poiyphemoides                  456*      56**       56*        46*                                                                       45        4*5**
                                                                                                                                                                                 6**
                        Evadne tergestina                                                    34**
                                                                                             5*6**     45*6**     56                                                   56*       56*
                        Penilia evirostris                                                   4**5**    456**      6**

                                                                                             6**
                        Tortanus setacaudatus                46        6


                        Centropages hamatus                            6*


                        Diaptomus spp.                                            1-4        1         15                   1245      1-@        1,         1          1-3


                        Labidocera aestiva                                                   6*        36*        56        6*        6*         6          6


                        Temora turbinata                                                               56*        6**                            6          6*         5         6


                        Unidentified CycLopidae                        1-4        1*23                 2          1         1245      1*-5       1-4        125        1*-3*     13


                        01thona nana                                                         23*4*     46*        45*6**    56**      45         56*        46*        456*      35


                        Oithona simpiex                                                      4*5**6    346*       2-4       56*       4          6**        6*         2456*     6


                        Oithona Ptumifera                                                                         6*        6


                        HaticycLops sp.                                                      1*5*      15         5         1*        12         3-5        1245       1         145













                      Table 5. Uncommon (<0.1% total numbers) species seasonal distribution. 24 samplings broken into 12 monthly sets of 2 collections
                                each. 1-6 indicates stations where present. * >100 percubic meter, ** >500 per cubic meter.


                                                          1         2        3          4        5         6          7        8         9         10        11         12


                      MesocycLops edax                                                                                         14        3         1


                      Ergasitidae                                            3-5        12*      1-5       12*34      345*     5         34        1-46      234        236
                                                                                        34*
                      Hiraci sp@
                           ja                                                                                                                                           2


                      Lucifec faxoni                                                             5         6*         5


                      Unidentified Chaetognatha           2                  5                   46*       56*        6*                 56*       45*6*     45*6*      4*5*6*


                      Sagitta hispida                                                            5*6*      56*


                      Sauitta tenuis                                                             5         3456**     5*6**    6**       56*       35*6*                56*


                      HEROPLANKTON

                      Nemertea


                      PoLyctadida


                      Cercaria                                                                                                                                          4


                      Oligochaeta                         2         1        1*235      1        2                    13*4     1*234     1*2*      1         123        13


                      Cypris Larvae                       23        3                   1*25*6* 6          356*       34*5*    56*       345*6**   345*6*    4*5*6**    46*


                      Stomatopod Larvae                                                                               6


                      Zoea                                56*       56       2-5        1**23**  1*23*     1**2*3*    2356*    2U        234       1234      4          2
                                                                                        4*5**6** 4*5*6**   4*5**6**            56**      56*       56**
                      Negatopa                                               6          235      5*6*      3456       5                  45













                      Table 5. Uncommon (<O.I% total numbers) species seasonal distribution. 24 samplings broken into 12 monthly sets of 2 collections
                                each. 1-6 indicates stations where present.         >100 percubic meter, ** >500 per cubic meter.


                                                          1         2         3         4         5          6        7          8         9         10        11         112


                      Mysis-zoea                                                                             245      46*        456       456                            6


                      Dipteran Larvae                     123       1234      1234      123       12         1        1*2*34     1234      1*2       1*2       1*23       1


                      Dipteran Pupae                                          23


                      Ephimoptera Larvae                                                                              12


                      Odonata                                                                                         12         1                             12         1


                      Bipinnaria                                                                  6**        6i       6*                   6                              6


                      Opheoptuteus                                                                6**        6**      6**        6*        6                   5**6**


                      Tornaria                                                                    6**        6**      6*                             6         45*6**


                      Actinotrocha                                                                                    6                    6


                      Cyphonauta                                                                                                                     56                   45


                      Ascidiacea (tadpole larvae)                   6                                        5


                      CephLochordata                                                    5*6**     5**6**     6**                                               56


                      Pisces Egg                          256*      6**       6**       12**3     5**        6*       2          6                             6*
                                                                                        4*5*6**
                      Pisces Larvae                                           56        5**6     @346*       6        6*         1456      5


                      TYCHOPLANKTON/ HYPOPLANKTON
                      Nematoda                            1.2345    1234      123       135*      15         12       123        1*23      123       1*345     123        123
                                                                    5*6*      456                                     45         45        456                 46         45*













                     Tabie 5. Uncommon (0.1% totaL numbers) species seasonaL distribution. 24 samptings broken into 12 monthLy sets of 2 cottections
                              each. 1-6 indicates stations where present. * >100 percubic meter, ** >500 per cubic meter.


                                                        1        2         3         4         5        6          7        8          9        10         11        12


                     Hydrazoan cotony fragments         5        6         2                                                           6                   2


                     Acarina                            12       13        136       13        4                                       1236                13        1


                     Ostracoda                          1*256    1*2*3     12*3*     1*2*3     1*2*3    1*3        1*2*34   1235       14       12         125       1*23
                                                                 4*56*     45*6*     56**      56*      56*                                                          45*6*
                     Parategastes sphericus                                          45*       356*     45         5        8                   45                   4-6


                     ftLu spp.                                                                 4                   6        6


                     Isopoda                            356      56        45        45*6      234      356*       2356     1356       123      134        45        45*6
                                                                                               56*                                     456      56*
                     Amphipoda                          36       5         2356      1*2*4     1*2**    1*24       12**     14         45       4          2345      245
                                                                                               35       56*        3**4
                     Cumacea                            56                 6         25        45       45                  5                              5         456


                     Mysidacea                          123      45        2346      4*5*6     123      1*23       345*     5          3        46*        1         1235
                                                        456                                    45*6*    456
                     PoLyctadida                        45*6*    56*       56        2*3       2**3**   25         6*       6          6        46*        6         56*
                                                                                     4*6**     4**6*
                     Tardigrada                                                                                    1        12         1









                      TabLe  6. Plankton category  abundance (number/m3    and Biomass (mg/m   3 in parentheses) averaged throughout the year by station.



                      PLANKTON TYPE                STATION I          STATION 2         STATION 3          STATION 4          STATION 5         STATION 6
                                                   (mile 8.8)         (mile 6.4)        (mile 4.4)         (mile 2.2)         (river mouth)     (bay)


                      HOLOPLANKTON                 29600              84100             150000             175000             232000            308000
                                                   (5.69)             (15.1)            (34.3)             (42.8)             (88.4)            (149.0)




                      HEROPLANKTON                 1490               4400              3190               4280               14500             41400
                                                   0.03)              (3.55)            0.66)              (2.86)             (5.68)            (22.6)




                      TYCHO/HYPOPLANKTON           1560               4620              6210               1300               1310              1540
                                                   (3.09)             02.7)             (11.3)             (2.54)             (3.45)            (3.69)













                                             A                                   N



                                          4b

                                                                                                     GULF
                                                                                                      OF
                                                                                ).km                MEXICO
                                   41


                                                      0
                                                                              RUSKIN INLET
                                      aco @--                       Cb
                                          04
                                                                                4

                                                                                     US 41








                                                                                             LITTLE MANATEE
                                                                                                   RIVER







                                                                                                     1-75
                                                                                          2






                                Fig. Ia. Map of Little Manatee River showing station locatio










                                              Fig. 1. Salinity.
                                              46                                                                                                                   STATION              8
                                                                                                                                                                   STATION              6
                                                                                                                                                                   STATION              4
                                                                                                                                                                   STATION              3
                                                                                                                                                                   STATION              2
                                              39                                                                                                                   STATION              I
                                          IL
                                          CL


                                              29
                                          1.4        -                                                1    1 13
                                          z          -        I %                       I   .I .         '911                                                 .... a.. *                I I
                                          14                                                                                                              .,Ar




                                                                                                    4P

                                                                             4                                        L2                   Is                   29                      24
                                                                                                      COLLECTION NUMBER                                                                 -


                                              Fig. 2. Temperature.
                                                                                                                                                          :7       STATION              6
                                              32                                                                           -4k                                     STATION              6
                                                                                                                                                                   STATION              4
                                                                                                                                 4(                                STATION              3
                                              28                                                                                                                   STATION              2
                                                                                                                                                                   STATION              I


                                          W   24


                                          <1
                                          cr  20
                                                                                                                                                                               00
                                          w


                                          w




                                                                            4                     8                  12                  Is                    29                       24
                                                                                                    COLLECTION NUMBER



                                              Fig.          3. Dissolved Oxygen.

                                              12


                                          cl
                                          9

                                                  8
                                          w                                        q@,Z -A,
                                                                             4rjr

                                          X
                                          0
                                          a       4                                                                              3L                                STATION              13
                                          w                                                                                                                        STATION              5
                                                                                                                                                                   STATION              4
                                          a       2                                                                                                                STATION              3
                                                                                                                                                                   STATION
                                                                                                                                                                   STATION
                                                                                                    a                 1,2                 I's                   20                      24
                                                                                                      COLLECTION             NUMBER
                                                                  F                     A           M        i         i          A         S         0            it      0            1
                                                                                                                                                                   STATION              2
                                                                                                                                                                               ON@
                                                                                                                                                                   STATI


















                                                      Fig. 4. Flow in the Little Manatee River during sampling.
                                                                             Readings taken near Wimauma.

                                                                                                           1. ..T- W           11.1 11 ... 11 1.  1.- 1..'' P, I W., 11.1. 1. 1111 .''1            11 W-T-        11 1-  P - 1-7
                                                                                                        .. . ... .....                                        . . .....
                                                                                                                                                                                                                    ...... . ..... ........ .... .







                                                                                                                                                   ... . ..... ..







                                                                                                                                                                                             ... ..... ..... ... .... ............... ..





                                                      W

                                                      U            660                         .... ... . ...                                                                       . ......                     . ...........
                                                      M



                                                      0

                                                                   400           .............. ..... .. ...... .......







                                                                    200







                                                                                                             .................. ........... ...........




                                                                                        a            4            a            a           I a          12           14           is          i a          29           22           24

                                                                                        F                        A                                    j            A           S           a            N           D           i
                                                                                  L           3             6           7            9           11.          13           Is           17           19           21           23




                                                                                                                                            COLLECTION NUMBER
















                     Fig. S. Copepod nauplii densities.

                                                      Lower Stations


                         IES




                     m
                     W                                       W4
                                                                       of,






                        loses





                         lose                                                         STATION 4
                                                                                      STATION 6
                                                                                      STATION 6



                         Lee

                               9         4                   12        Is        20         a4



                                                      Upper  Stations



                         ins

                     OU99966                                                     +i%
                     W




                        logos




                        lose -



                                                                                      STATION  I
                         lee -                                                        STATION  2
                                                                                      STATION  3



                           to

                                0         4         a        12        Is        20         24
                                                     COLLZCTION NUMEER

                                             A         j    i    A    S    0    N     0
                                                                     , If-
















                        Fig. 6. 0ithona colcarva densities.

                                                         Lower Stations


                           LES -



                        losses -



                          loose-
                          lose -                                     41

                       L
                       m   Lee -

                                                                                      STATION 4
                                                                                      STATION 5
                                                                                      STATION 6





                                 a         4                   12         Is         20




                                                        upper stations
                        losses                                                        STATION I
                                                                                      STATION 2
                                                                                      STATION 3
                       m loose
                       W
                       W
                       E


                          lose




                       0.   Lee











                                 9         4                   12        le          20       24
                                                       COLLECTION  NUMBER
                               i    F         A               i    A    S    0    0    D     j















                    Fig. 7. Acartia tonsa densities.

                                                       Lower Stations


                       Laos@@
                                                            A



                        lease




                         loss




                   W
                   IL     Lee
                   m
                   W
                                                                                       STATION 4
                                                                                       STATION a
                                                                                       STATION 6





                                          4                   12        IS        as         24




                                                       Upper Stations

                       losses
                                                                                       STATION L
                                                                                       STATION 2
                   m    loses                                                          STATION 3
                                                            41



                         lose




                   L      Lee                                                           A


                   W
                   m

                   x       is



                                                                        T

                                          4                   12        Is        29        24
                                                      COLLECTION NUMBER
                                   F    N         14   1     1    A    S    0    N     0   j














                      Fig. 8. Benthic harpacticoid copepod densities.

                                                        Lower Stations
                       losses -                                                      STATION 4
                                                                                     STATION 6
                                                                                     STATION 6
                      m  Lose@
                      W




                          lose


                                                                                 Ad
                      m
                      W
                      IL   Lee


                      W


                      z






                                 0         4         a          12       3.6        as       a4




                                                        upper Stations


                       losses                                     V


                                                                                     STATION I
                                                                                     STATION 2
                      m  loses                                                       STATION 3
                                                                 f

                          loss               iL


                      m
                      IL   Lee



                      X






                                        . . . . . . . . . . .

                                           4         a          12                  20       24
                                                       COLLECTION NUMBER
                                    F         A                   A    S    0    v    0    1














                     Fig. 9. Rotifer densities.

                                                         Lower Stations


                        LOGO@$ -
                                                             STATION 4
                                                             STATION  5
                                                             STATION  8
                         less@ -
                        W




                           lose




                            Is$









                                  9         4          a        12        Is        20         84



                                                         Upper Stations

                        Leese$                                            STATION I
                                                                          STATION 2
                                                                          STATION 3
                        cc  less*
                                                           +


                                                                               /*
                           lose




                             Lee

                                                                 f


                              Is




                                  0         4          a        12         Is        20
                                                        COLLECTION  NUMBER
                                j     F    N    A              i    A    S    0    W    0    1















                       Fiq. 10. Polychaete larvae densities.


                                                         Lower.Statiame


                           LES



                                                                                      STATION  4
                                                                                      STATION  5
                       w
                                                                                      STATION  6


                                   +     41"
                         loses

                                                                  .A


                           lose




                           Los






                                 9         4          8         12        Is         29        24.




                                                         Upper stations


                           LES -



                                                                                      STATION I
                       mlosses -                                                      STATION 2
                                                                                      STATION 3

                        loose -



                          lose -


                                           ML

                           Lee



                             "s



                              I

                                  9         4         a         12        Is         @20       24
                                                        COLLECTION NUMBER
                                    F                                   S    0     V    0    1














                       Fig..11. Pseudodiaptomus            coronatus densities.

                                                        Lower Stations
                       lose@@ -                                                        STATION 4
                                                                                       STATION 6
                                                                                       STATION 6
                        lose@ -








                                                                      +
                      IL   Lee











                                0          4         a        12        is        20        a4




                                                        Upper Stations
                       Laos@@                                                          STATION I
                                                                                       STATION 2
                                                                                       STATION 3
                      m  Lee@*
                      W




                      04  jSQ4



                                                          +
                           loo                            A...-
                                                          v


                                                           t





                                                             ti


                                                              12        is        29        24
                                                      COLLECTION  NUMBER
                               i    F         A         i    i    A    S    0        D    i















                   Fig. 12. Par      vocalanus crassirostris densities.


                                                       Lower  Stations


                       losses




                                                       lk
                      W  Less*



                          lose




                           Lee





                                                                                    STATION 4
                                                                                    STATION 5
                                                                                    STATION 6


                                          4                   12        is          20       24




                                                        Upper Stations
                       Looses -                                                     STATION I
                       WLOGO@ -                                                     STATION 2
                                                                                    STATION 3



                         lose -




                           Lee









                                                                  .... .... ....
                                                                    ! ! L
                                 0         4         8        L2        Is          20       24
                                                      COLLECTION NUMBER

                                    F         A                   A    &    0















                      Piq. 13. Euterping acutifrons densities.


                                                        Lower Stations
                       Lease@                                                        STATION 4
                                                                                     STATION 6
                                                                                     STATION 6
                         loses




                                                                                           W*
                          lose




                           lee




                            Is






                                          4                   12         is         29       24




                                                        upper stations

                       looses -



                                                                                     STATION I
                      m Lease -                                                      STATION 2
                      ,W-                                                            STATION 3


                         Lose.-




                           lee




                      z     Is






                                 0         4                  12        is         20       24
                                                      COLLECTION NUMBER
                                    F                             A    S    a














                              Fig. 14. oikipleura dioica densities.

                                 losses -                                                      STATION 4

                                                                                               STATION  6

                                                                 Or
                                                                                               STATION  6

                                   lease






                                                               f I


                                    LOGO


                                14






                                     Lee
                                                         rI




                                      Is












                                          9          4         a         L2        Is         20       24


                                                                 COLLECTION NUMBER
                                             F           A   x          j    A     S    0      v   0    1











                    Fig. 15. Saphirella spp- densities.

                                                         Lower Stations


                         less@@




                          loose                                                    .... ...


                                                                        or

                           lose




                     W
                     IL     Lee



                                                                                      STATION 4
                     z       Is                                                       STATION 6
                                                                                      STATION 8
                                                           Lf




                                 0         4          a        12         is         20       24



                                                         Upper Stations


                         199990



                                                                                      STATION L
                          loses                                                       STATION 2
                     W
                                                                                      STATION 3



                     04    1.900
                                                               N.



                     0.     lee
                     m



                             is






                                            4         a        12         IS         20       24
                                                       COLLECTION  NUMBER
                               j    F    N    A                    A    S    0    m    D    i
















                         Fig. 16. Eurytemora hirundoides densities.


                                                         Lowar Stations
                         lose* -                                                      STATION 4
                                                                                      STATION 6
                                                                                      STATION 6

                          logo -






                           lee -




                       w







                                             .... . .... ....            .... .... ....
                                                      L  . . .  L -
                                            4         8        12         is         as       24




                                                                                      STATION I
                                                        Upper Stations                TATXON  2
                         loose                                                        :TATZON 3

                       m
                       @W_  Lose
                       w
                                             A




                            lee





                             is






                                                                          L         -j
                                 a         4         a         1.2       is          as       24
                                                       COLLECTION  NUMBER

                              i    F    0    A    0          1    A    S
                                      t















                         Fig. 17. Bivalve larvae densities.


                                                         Lower Stations


                        looses
                                                                                STATION 4
                                                                                STATION 6
                                                                                STATION 6   /+I
                      m   lose$
                                                     At                                   4


                      04   lose




                            Is$                                              f1k










                                 0         4                   12         Is        20        24




                                                         Upper Stations



                                                                                STATION I
                                                                                STATION 2
                                                                                STATION 3
                         Loose




                           lose














                                                                                4. 4. 4. 4. -
                               t7,                                              , , -I- '
                                 s          4         a        12        is         29        24
                                                       COLLECTION NUMOER
                                i    F         A                   A    S    0















                       Fig* 18. Gastropod larvae densities.


                                                         Lower Stations








                           lose
                                                                                :10,




                            Lee
                        m
                        W



                                                                                      STATION 4
                        z                                                             STATION 6
                                                                                      STATION 6





                                           4          13       12         Is         29       24



                                                        upper stations

                         Lee@*



                                                                                      STATION I
                                                                                      STATION 2
                        W
                           Lose                                                       STATION 3
                                                       'P.


                            lee












                              L

                                            4         a        12         Le         29       24
                                                       COLLECTION NUMBER

                               i     F   N     A              i    A         0    m    0    1















                        Fig. 19. Barnacle nauplii densities.

                                                        Lower Stations


                         loses

                                                                                               +


                                    W%,
                                                                         d
                          3.990






                           Lee



                                                                                     STATION 4
                                                                                     STATION 5
                            is
                                                                                     STATION 6







                                0         4          a         L2        Is         20        24




                                                        upper Stations
                                                                                     STATION I
                         loose                                                       STATION 2
                                                                                     STATION 3




                          lose

                                                               +i



                           Lee




                                                                                      ti
                                        1k








                                          4                   12                    29        24
                                                      COLLZCTXQN  NUMBER

                              i     F   N     A         i    j    A         0    N    0










                        Fig. 20. Zooplankton abundance and Biomass by station.

                               ASUNCANCE (Number or Cubic motor)                   BIOMASS (mY,Drw weight)
                                               STATION I                                    STA
                                                                                                  ON I
                   A.        IES                                    HOLOPL.
                                                                    MEROPL.                              0 HOLOPL.
                          losses-                                   TYCH PL.                             0 MEROPL.
                                                                                                        0TYCHOPL.
                                                                               290-
                           Isess-



                            ISO@ -
                                                                               ISO





                                  a     4      a    12    16     29   24             0   4   8 12 IS 20 24


                   B.        IES -             STATION   2                    308-         STATION 2

                                                                                                       E HOLOPL.
                          looses-                                                                      0 MEROPL.
                                                                                                       0 TYCHOPL.
                                                                              age-




                           1.000 -
                                                                    4.-4r
                                                                              lee


                                                                    HOLOPL.
                                                                    MEROPL.
                                                                    TYCHOPL.
                                  a     4      B    11,   Is     29   24            0   4   8 12    IS 29 24


                                               STATION   3                                 STATION 3
                    C.       IES                                              309

                                                                                                       E HOLOPL
                          loo0 "a                                                                      0 MEROPL:
                                                                                                       C3 TYCHOPL.
                           lease-                                             200

                           lose -                                 3j,

                                                         or

                                                                    HOLOPL.
                                                                    MEROPL.
                               9                                    TYCHOPL.'     a
                                  a     4      a   12     16     20.  24            0   4   8 12 1.6 29 24
                                          COLLECTION NUMBER                           COLLECTION NUMBER
                                                                                                      AA








                      Fig. 20. Zooplankton abundance and Biomass by station.

                            ABUNDANCE-'(Number,for Cubic Motor)        BIOMASS 9 t(,nFcubic meter)
                                           STATI N 4                                  on  4
                 D.      LES -                                        see-

                                                                                            0 HOLOPL.
                       losses-                                        490-                  0 MEROPL.
                                                                                            0 TYCHOPL.
                        loses-         r4  A    /+                    ass'
                                +          K@ I",M
                         lose-                                        290


                         Lee -    4                        HOLOPL.    Lee
                                                           MEROPL.
                                                           TYCHOPL.
                            ler,
                               0   4       s  12    IS-   29  24           a  4 6 12 16 20      24


                 E.      IES               STATION 5                  see-      STATION 6
                                                                                            N HOLOPL.
                                                                                               MEROPL.
                                                                                            OTYCHOPL.
                                                                      489*
                       losses-

                                           +
                                      IIk  11                         300
                        loses-

                                                                      200



                                                                      lee
                                              HOLOPLI.
                                     if       MEROPL.x
                         lee                  TYCHOPL
                                              - Li- - L
                               0   4       8  12    16    29  24           0  4 8 12 16 29 24




                                           STATION 6                            STATION 6
                         LES                                          See-

                       losses-                                                                 HOLOPL.
                                                                      400-                  0 MEROPL.
                                            *4                                              13TYCHOPL.
                        loses-                                        ass
                                  +ak
                         lose-

                                                                      200
                         lee


                                                                      lee
                          Is -             HOLOPL.
                                       --MEROPL*:                                     /AAR
                                           TYCHOPL.:
                                                  A

                               a   4       a  12    Is  2 0   24           0 4   8 12 IS 29 24
                                     COLLECTION NUMBER                      COLLECTION NUMBER













               Fig. 21. Total zooplankton abundance and biomass averaged for the
                            river (stations 1-5).



                        IES -






                     lessee -






                      loose -



                                                                      Ar



                        lose
                                                                9 W\. 40
                                    -A            HOLOPL.
                                                  MEROPL.
                                                  TYCHOPL.

                                                           L. ' - - L
                              a        4         8        1.2       1.6      20        24
                                                   COLLECTION NUMBER



                         Lee


                         158                                        HOLOPL.
                                                                    MEROPL.
                                                                C:1 TYCHOPL..

                         126









                          Be




                          30






                             0       4      a      12     Is      26     24

                                           COLLECTION NUMBER



                                                                                                                       NOAA COASTAL SERVICES CTR LIBRARY          I
                                                                                                                       3 6668 14111393 8                           1
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