Unique ecological features of the Louisiana coast

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

Coastal Zone
Information
Center
UNIQUE
ECOLOGY
FEATURES
OF THE LOUISIANA C0AST

PREPARED FOR

THE LOUISIANA STATE PLANNING OFFICE

QH
541.5
C65
U55
1976 engineers planners environmental scientists

C) 17 4(0

NO E

OF THE LOUISIANA C MIT

PREPAREO FOR
THE LOUISIANA STATE PLANNING OFFICE

COASTAL RESOURCES PROGRAM

BATON ROUGE LOUISIANA

JUNE 1976

engineers planners environrnental scientists
4176 CANAL ST. NEW ORLEANS,LA. 70119 504-486-5901

The preparation of this report was financed in part through a. grant from the
U.S. Department of Commerce under the provisions of the Coastal Zone
Management Act of 1972.

U S. Department of Commerce under the provisions of the Coastal Zone
Management Act of 1972.

NOTICE

This document is disseminated under the sponsorship of the Louisiana
State Planning Office in the interest of information exchange. The State
of Louisiana assumes no liability for its contents or the use thereof.

TABLE OF CONTENTS

,Page

INTRODUCTION . . . . . . . 1
ENVIRONMENTAL MANAGEMENT UNITS . . . . . . . . . . . . 2

ZOOLOGICAL FEATURES
1. Endangered Species Habitats . . . . . . . . . . .. . . . 3
a. Southern Bald Eagle Nests . . . . . . . . . . . . . 3
b. Brown Pelican Nesting Area . . . . . . . . . . . . 4
c. Red Wolf . . . . . . . . . . . . . . . . . . . . 4
d. American Alligator . . . . . . . . . . . . . . . . 4
2. Seabird Colonies and Wading Bird Rookeries . . . . . . . 5
3. Primary Fish and Shellfish Nursery Grounds . . . . . . . 9
4. Public Oyster Seed Grounds . . . . . . . . . . . . . . 10
5. Privately Leased Oyster Beds . . ... . . . . . . . . . . 11
6. Live Rangia Clam Beds . . .. . . . . . . . . . 12
7 Exposed Shell Reefs . . . . . . . . . . . . . . . . . 12
8. Other Unique Wildlife Habitat 13
a . Sea Turtle Nesting Area in Chandeleur island; 13
b. White-tailed Deer' Concentrations
(Mississippi Delta) . . . . . . . . . . . . . . . . 14
c. Black Bear -Atchafalaya Basin . . . . . . . . . . . 14
d. Red Swamp Crayfish - Atchafalaya Basin . . . . . . . 15
e. Roseate Spoonbill - Sabine Refuge . . . . . . . . . 16
f. Big Burn - Deep Peat Burn Near Creole
. . . . . . 16
g. American Oil Company Waterfowl Impound-
ment South of Gueydan . . . . . . . . . . .. . . . 17
h. Peak Duck Concentrations . . . . . . . . . . . . . 17
i. Geese Concentrations . . . . . . . . . . . . . . . 19
j. Osprey Nest . . . .. . . . . . . . . . . . . . . . 20
9. Unique Fishery Habitat - the Barataria Basin . . . . . . . 20

BOTANICAL FEATURES
1. Unique Botanical Specimens or Communities . ... . . . . 22
2. Submergent Grass Beds ... . . . . . . . . . . . 24
3. Black Mangrove Areas (Avicennia nitida . . . . . . . . . 26
4. Bottomland Hardwoods . . . . . . . . . ... . . . . . . 27

GEOLOGICAL FEATURES
1. Barrier Islands and Beaches . . . . . . . . . . ... . . 29
2. Deep Migratory Tidal Passes . . . . . . . . . . . . . . 31
3. Cheniers and Beach Ridges . . . . . . . . . .. . . . . . 33
4. Salt Domes . . . . . . . . . ... . . . . . . . . . . 34

Paqe

5. Mud Lumps . . . . . . . . . . . . . . . . . . . . . . 35
6. Freshwater Impoundments in the Marshes . . . . . . . 35
7, New Atchafalaya Delta . . . . . . . . . . o . . o 37
8. Big Woods Island, Deweyville Terrace . . . . 0 38

MISCELLANEOUS FEATURES
1. Potential Registered Natural Landmarks . . .. . . . . 39

UNIQUE ECOLOGICAL FEATURES
OF THE
LOUISIANA COAST

INTRODUCTION

The Louisiana coast possesses a richness and diversity of natural
resources that is unparalleled in the United States. From the ecological
standpoint, the coastal deltaic and chenier plains have many unique
features. The diverse habitats provided by isolated Pleistocene deposits,
alluvial ridges, swamps, marshes, cheniers, salt domes, beaches, bays
and nearshore Gulf waters support extremely dynamic and productive biotic
communities.

In addition to supporting dense populations of many commercially
important species, critical habitat for several rare or endangered species
is provided. The marshes and bays of the coastal area are responsible for
Louisiana being the premier state in annual production of fisheries and fur.
This phenomenal productivity is in itself unique, for the Louisiana marshes
are among the largest and most productive in the world. The brackish and
saline marshes serve as prime nursery grounds for over 100 species of
estuarine dependent fish and shellfish. The majority of species that are the
basis of Louisiana's renowned commercial and sport fishery utilize these
marshes during certain phases of their life cycle. Louisiana's wetlands
normally winter five to six million waterfowl and provide nesting habitat for
many species of wading and sea birds.

This report describes twenty three categories of unique ecological
features of the Louisiana coast. These features have been divided into
zoological, botanical and geological components. A unique ecological
feature is defined as an area or a resource that is either (1) critical habitat
for rare or endangered species, (2) of extremely high biological product-
ivity, (3) of vital importance as a nesting, feeding, wintering or spawning
area for fish and wildlife, (4) a rare or unusual occurrence for a species
that may be near the limits of its range, (5) vital to the maintenance of a
coastal ecological process , (6) a unique physiographic feature or (7) of
exceptional recreational value. For each feature, the location, number,
approximate size or acreage, unique importance and source of information is
presented. Reference should be made to the unique ecological features
overlay on which these features are mapped.

ENVIRONMENTAL MANAGEMENT UNITS

The Louisiana coast has been divided into nine environmental manage-
ment units represented by Roman numerals on the overlay. These units
correspond to hydrologic units which are natural catchment and drainage
basins opened to the Gulf of Mexico. For purposes of coastal management,
the landward boundary of these units is the coastal zone boundary. The
natural levees of bayous and rivers and certain man-made features divide
the environmental management units into natural drainage basins. These
units are hydrologically distinct and can be managed as separate sub-
systems. The geographical boundaries of each environmental management
unit is as follows:

Environmental
Management Unit Boundaries

I Coastal zone boundary to Pearl River to Bayou
Terre aux Boeuf, including Lakes Maurepas and
Pontchartrain

II Bayou Terre aux Boeuf to the Mississippi River

III Active Mississippi Delta south of Baptiste Collette
Pass and Red Pass

IV Mississippi River to Bayou Lafourche including the
Barataria Basin

V Bayou Lafourche to the Atchafalaya River

VI Atchafalaya River to the Wax Lake Outlet, including
the Atchafalaya Basin

VII Wax Lake Outlet to Freshwater Bayou, including
Vermilion Bay

VIII Freshwater Bayou to Highway 27 and the Creole
Canal including the Mermentau Basin

Ix Highway 27 and the Creole Canal to Sabine Pass
including the Calcasieu and Sabine Basins

ZOOLOGICAL
FEATURES

Av.

Southern Bald Eagle nest on oak ridge below Lafitte
v
@5

A. ZOOLOGICAL FEATURES

I Endangered Species Habitats

a. Southern Bald Eagle Nests
Seven,active confirmed nests of Southern Bald Eagles arc
known in coastal Louisiana. Eagles migrate into the area in September and
nest in the winter months. Nests are usually built in large cypress
or oak trees located on natural levee ridges such as are found along some
abandoned river distributaries. Young eagles are ready to leave the nest by
March. Other nesting sites have been reported but are unconfirmed by the
Fish and Wildlife Service. Three possible nesting locations are north of Lake
Boeuf, near Grassy Lake in the Atchafalaya Basin and on the Lacassine Refuge.

The seven confirmed nesting sites are in the following locations:

1) Bayou Mauvais Bois natural levee ridge approximately one-half
mile northeast of Peoples Canal; Terrebonne Parish, Environmental Manage-
ment Unit V.
2) Bayou Black natural levee ridge approximately one mile south of
Greenwood, Louisiana; Terrebonne Parish, Environmental Management Unit V.
3) Turtle Bayou, approximately one mile south of the Intracoastal
Waterway and 6 miles southeast of Amelia, Louisiana; Terrebonne Parish,
Environmental Management Unit V.
4) Avoca Island, near Bayou Chene about three miles northeast of
the junction of Bayou Chene and Bayou Penchant; St. Mary Parish, Environ-
mental Management Unit V.
5) Natural levee ridge along abandoned portion of Bayou Barataria
approximately one mile east of Bayou Rigolettes; fefferson Parish, Environ-
mental Management Unit IV.
6) Natural levee ridge along abandoned portion of Bayou Barataria,
approximately one mile south of site 5; fefferson Parish, Environmental
Management Unit IV.
7) Bayou Bois Piquant natural levee ridge approximately one-half
mile north of the junction of Bayou Bois Piquant and Louisiana Cypress Lumber
Canal; St. Charles Parish, Environmental Management Unit IV.

Source of Information: Ray Acock, Fish. and Wildlife Service, Baton
Rouge. Personal communication.

b. Brown Pelican Nesting Are
There is a small colony of brown pelicans that live and nest
in the Queen Bess Island and Grand Terre Islands area of southern Barataria
Bay. The population has fluctuated between one hundred and four hundred
birds due to recent die-offs. 'Currently there are 170 adults by head count.
Successful nesting was observed in March, 1976 when 35 young pelicans
and 30 eggs were counted in nests on Queen Bess Island.

The pelicans can usually be found feeding from sand spits or shell
reefs and nest in black mangrove of these islands. They range out of this
area westward to Bay Champagne and eastward towards Four Bayous Pass.
The range covers portions of southern Lafourche, Jefferson and Plaqueminos
Parishes and is in Environmental Mana' gement Unit IV.

Source of Information: Louisiana Wildlife and Fisheries Commission.

c. Red Wolf
There are a few remaining red wolves in Southwestern Louis-
iana in Cameron and Vermilion Parishes. This wolf has hybridized with the
dog and coyote and pure strains are not common. The Red Wolf usually is
found on the higher ridges and cheniers that are found throughout the prairie
marshes of the Chenier Plain.

Environmental Management Units VIII and IX.

Source of Information: Fish and Wildlife Service.

d. American Alligat
Although an endangered species in the United States, the
American Alligator is not considered either rare or endangered in coastal
Louisiana. An estimated 250,000 alligators reside in the state's wetlands.
The abundance of alligators in the freshwater swamps and marshes of the
coastal zone is unique in itself, for nowhere else in the United States is
there habitat to support similar numbers.

. Although alligators are widespread throughout the coastal area, and
are found in all nine'environmental management units, peak concentrations
occur in the freshwater marshes of Southwestern Louisiana, particularly on
the state and federal wildlife refuges., 'Large alligator populations are seldom
found in marshes where salinities greatly exceed 10 ppt. The ecological
features overlay shows areas of peak alligator concentrations in coastal
Louisiana. It should be noted that each alligator symbol on the overlay re-
presents general areas where alligator populations are higher. Alligators are
also found in adjacent areas where their range and population is increasing.
Peak concentrations occur in the following general areas:

I Art

CIL

21W,
-007
Ah

5@
I
A Vf
IAK

-3s.,

47,
IF

24 NI
lop; -'off tot

American alligator atop alligator weed

1) Sabine Refuge, west of Highway 27, Cameron Parish
2) Lacassine Refuge pool, Cameron Parish
3) Freshwater marshes south of Grand Lake, Cameron Parish
4) Rockefeller Refuge impoundments, Cameron Parish
5) Marsh Island, Iberia Parish
6) Marshes north of West Cote Blanche Bay, St. Mary Parish
7) Atchafalaya Basin, St. Mary Parish
8) Turtle Bayou - Bayou Penchant area, Terrebonne Parish
9) Carencro Lake area,; Terrebonne Parish
10) Rathborne Swamp area west of Lake Boeuf, Lafourche Parish
11) Lake Maurepas Swamp, St. John the Baptist Parish
12) Freshwater marsh west of Lake Salvador, St. Charles and
Lafourche Parishes
13) Mississippi River Delta, Plaquemines Parish
14) Delacroix Island area westward towards the Mississippi
River, Plaquemines and St. Bernard' Parishes
15) Honey Island Swamp and freshwater marsh near mouth of
Pearl River, St. Tammany Parish

Source of Information:
Burk and Associates, Inc. Field surveys by staff personnel.
Chabreck, Robert H. U.S. Fish and Wildlife Servico.
,Personal communication.
Ensminger, Allen. Louisiana. Wildlife and Fisheries
Commission. Personal communication.
O'Neil, Ted. Louisiana Wildlife and Fisheries Commission.
Personal communication.

2. Seabird Colonies and Wading Bird Rookeries
Seabirds and wading birds utilize the Louisiana coastal wetlands
heavily for nesting. Several surveys of nesting colonies and rookeries have
been made in recent years by the Fish and Wildlife Service and the National
Audubon Society. The most recent, upon which the following list is largely
based, is currently being done by John Portnoy of the Louisiana Cooperative
Wildlife Research Unit in Baton Rouge.

The sites in the following list are locations that have been used for
nesting at least once since 1973 with the great majority having active nest-ing
every season. The seabird colonies are most heavily used by laughing gulls,
least, royal and. sandwich terns, black skimmers and willets. Wading birds
occurring most commonly in rookeries are great blue, Louisiana and little
blue herons; yellow and black-crowned night herons; American, common,
snowy and cattle egrets; white-faced, white and glossy ibises and anhingas.
The brown pelican rookery on Queen Bess Island was considered separately
because of the bird's endangered status.

No. lype Location Parish Latitude Longitude
Rookery Johnson's Bayou Cameron 93049-
1 29549
2 Rookery Shell Hill, Sabine Cameron 290SS' 93034'
Refuge
3 Rookery Pool I-B, Sabine Cameron 29052' 93027'
Refuge
4 Rookery Pool 1-A, Sabine Cameron 29055' 93026'
Refuge
5 Rookery North of Black Lake Cameron 30003' 93024'
6 Rookery Rabbit Island ' Cameron 93022'
7 Rookery West of Creole Cameron 29053' 93007'
Canal
8 Rookery Little Chenier Cameron 29051' 92058'
9 Rookery Lacassine Refuge Cameron 30000' 92056'
10 Rookery Blue Grove, Cameron 29057' 92056'
Lacassine Refuge
11 Rookery Black Grove, Cameron 29057' 92055'
Lacassine Refuge
12 Rookery North shore Lake Cameron 29055.' 92054'
Misere
13 Rooke*r-y Lacassine Refuge Cameron 29059' 92051'
14 Rookery Lacassine Refuge Cameron 29058' 92051'
15 Rookery La *cassine Refuge Cameron 30000' 92050'
16 Rookery North end Grand Cameron 29058' 92047'
Lake
17 Rookery Northeast of Verm ilion 29052' 92037'
Blackfish Lake
18 Rookery Grand Volle Lake Vermilion 29043' 92035'
19 Rookery North of Chenier Vermilion 29036' 92014'
au Tigre
20 Rookery Belle Isle (Raihey Vermilion 29037' 92011'
Refuge)
21 Colony Belle Isle Lake Vermilion 29041' 92012'
22 Rookery West of Southwest Vermilion 29035' 92005'
Pass
23 Rookery Deadman Island, Vermilion 29035' 92001'
Vermilion Bay
24 Rookery Avery Island Iberia 29055' 91055'
25 Rookery Avery Island Iberia 29053' 91052'
26 Rookery Weeks Island Iberia 29048' 91048'
27 Rookery Weeks Island Iberia 29049' 9105S'
28 Colony Shell Keys Refuge Iberia 29036' 91050'
29 Rookery East of Weeks Iberia 29049' 91044'
Island
30 Rookery West of Franklin St. Mary 29048' 91034'
31 Rookery ICV\rW and Bayou St. Mary 29026' 91050'
Sale
32 Rookery Eugene Island St. Mary 29022' 91024'

11"

.-M.AAM "57-

Wading bird rookery on mangrove island

in Southern Barataria Bay

No. lype Location Parish Latitude Longitude
33 Colony Point au Fer St. Mary 29020' 9102 V
34 Rookery North of Sweet- St. Mary 29037' 91014'
bay Lake
35 Rookery East of Sweetbay Terrebonne 29034' 91013'
Lake
36 Rookery Palmetto Bayou Terrebonne, 29028' 91022'
37 Rookery South of Kent Bayou Terrebonne 29036' 911,08,
38 Rookery Near Bayou L'Ourse Assumption 29042' 91QO3'
east of Amelia
39 Colony Raccoon Point on Terrebonne 29004' 90058'
Isle Dernieres
40 Rookery just east of Terrebonne, 29003' 90057'
Raccoon Point
41 Rookery Isle Derniere Terrebonne 29003' 90044'
42 Rookery South of Lake Terrebonne 29026' 90056'
Penchant
43 Rookery North of Lake Terrebonne 29025' 90054'
De Cade
44 Rookery Lake Hatch TerTebonne 29031' 90048'
45 Rookery Island east of Terrebonne 29003' 90044'
Whiskey Pass
46 Rookery Island 1 mi. NE Terrebonne 29004' 90043'
of # 45
47 Rookery Point Mast Terrebonne 29006' 90038'
48 Rookery Lake Boeuf Lafourche 29048' 90040'
49 Rookery NW shore of Livingston 30018' 90034'
Lake Maurepas
50 Rookery Ponchatoula Marsh Tangipahoa 30024' 9 0112 4'
51 Rookery Swamp south of St. John the 30006' 90030'
Lake Maurepas Baptist
52 Rookery East of Lac Des St. Charles 29056' 90030'
Allemands,
53 Rookery West of Lake Lafourche 29039' 90024'
Salvador
54 Rookery South of Long Lake Lafourche 29034' 90033'
55 Rookery Timbalier Island Terrebonne 29006' 90032'
56 Rookery SW of jacko Bay Terrebonne 29011' 90029'
57 Rookery East of Old Lady Lafourche 29014' 90024'
Lake
58 Rookery Felicity Island Lafourche 29018' 90023'
59 Rookery' 4 mi. W. of Lafourche 29041' 90025'
Temple Bay
60 Rookery 1 mi. NW of #59 Lafourche 29)42' 90026'
61 Rookery NW of Pierle Bay Lafourche, 29011' 90019,
62 Rookery West of Pierle Bay Lafourche 29010' 90017'
63 Rookery Devils Island Lafourche' 29009' 90016,

E -0. YyRe Location Parish Latitude Longitud
64 Rookery Bay Marchand Lafourche 29005' 90013'
65. Rookery Bayou L'Ours Lafourche 29026' 90013'
66 Rookery Caminada Bay Lafourche 29017' 90003'
67 Rookery New Orleans East Orleans 30002' 89059,
68 Rookery West Champagne Jefferson 29016' 90005'
Bay
69 Rookery Queen Bess Jefferson 29018' 890S7'
70 Colony Pass Abel Jefferson 29018' 89055'
71 Rookery Crane Island Plaquemines 29023' 890S3'
72 Rookery North of Big Plaquemine s 29025' 89"51'
Island
73 Rookery Gulf shore 3 mi. W Plaquemines 29019' 89049'
of Robinson Canal
74 Colony Bay joeWise Plaquemines 29018' 89043'
75 Rookery Bayou Grand St. Bernard 29056' 89)44'
76 Rookery SE. of Long Bay Plaquemines 29029' 89039'
77 Rookery Lanaux Island Plaquemines 29016' 89)38'
78 Rookery Pelican Island Plaquemines 29015' 89036'
79 Rookery Sandy Point Plaquemines 29013' 89028'
80 Colony SW. Pass Spoil Plaquemines 28057' 89024'
Bank
81 Rookery Between Zinzin Plaquemines 29008' 89" 18'
Bay & Riverside Bay
82 Rookery 1/2 mi. North of Plaquemines 29014' 89016'
Quarantine Station
83 Rookery 3/4 mi. North of Plaquemines 29015' 89o 15'
Main Pass
84 Colony Pass a Loutre Mud Plaquemines 29011' 89000,
Lump
85 Rookery Carencro Bay Island Plaquemines 29023' 89020'
S. of Bird Island
86 Rookery Bird Island Plaquemines 29024' 89" 19'
87 Colony Telegraph Point Plaquemines 29033' 89)3 1'
88 Colony Mozambique Point Plaquemines 29040' 89031'
89 Rookery S.W. Lake St. Bernard 29041' 89031'
Machias
90 Rookery Raccoon Island Area 29039' 89028'
91 Rookery Island W. of Dead- St. Bernard 29044' 89022'
man Point
92 Colony Point Chicot St. Bernard 29044' 89o 16'
93 Rookery Anderson Point St. Bernard 29054' 89c)20'
94 Rookery Conkey Cove St. Bernard 29056' 89015'
95 Colony Isle au Pitre St. Bernard 30009' 89o 10'
96 Rookery Martin Island St. Bernard 29058' 89o 1 V
97 Rookery Mitchell Island St. Bernard 29054' 89012'
98 Colony North Island St. Bernard 29053' 88)53'

"Owl 4
AL.

4',

& 0-1: 't@w

White Pelicans on East Timbalier Island

No. lype Location Parish Latitude Lon2itude
T9
99 Colony New Harbor Island St. Bernard 5P 88 U511
100 Colony Redfish Point St. Bernard 290 53' 88 048'
101 Colony Monkey Island St. Bernard 290 48' 88 0511
102 Colony Curlew Island Plaquemines 290 38' 88 058'
103 Colony Grand Gosier Plaquemines 290 34' 89 004'
Island
104 Colony S. Breton Island Plaquemines 290 291 89 011,
105 Colony S. Breton Island Plaquemines 290 281 89 013'
106 Rookery Lower Cow Island St. Martin 300 09, 91 03 V

Source of Information:
Brown, Bobby W. Refuge Manager, Lacassine National Wildlife
Refuge. Written communication.
Portnoy, fohn W. Louisiana Cooperative Wildlife Research Unit,
LSU, Baton Rouge, La. Written communication.
U.S. Fish and Wildlife Service. 1975 Wading Bird Rookery
Survey.

3. Primary Fish and Shellfish Nursery Grounds
Nursery grounds are shallow estuarine marbhes vital to the
juvenile stages of estuarine dependent fish and shellfish. The great majority
of commercial and sport fish and shellfish harvested along the Louisiana coast
are dependent on nursery grounds for completion of the early life history
stages of their life cycle. Called nursery grounds because they are used
during post larval and juvenile stages, these areas are unique because they
support one of the world's largest estuarine fisheries. Estuarine dependent
organisms rely on these waters to provide food, habitat, favorable growth
conditions and protection from predators during vulnerable periods of their
lives. The nursery grounds also provide important habitat for migratory water-
fowl, fur-bearing animals and many other forms of wildlife and support an
increasingly important sport fishing and recreational industry.

Although utilized by well over 100 species of fishes and invertebrates,
the dominant species are bay anchovy (Anchoa mitchilli), Atlantic croaker
(Micropogon undulatus), Gulf menhaden (Brevoortia Patronus) . Atlantic
threadfin (Polydactylus octonemus , spot (Leiostomus xanthurus) white shrimp
(Penaeus setiferus), brown shrimp (Penaeus aztecus) and blue crab (Calli-
necte sa2idu ). All but the bay anchovy are commercially important.

The primary nursery grounds shown on the unique ecological features
overlay were delineated on the basis of salinity zones, marsh vegetation
and marsh-water interface. The inland limit of the nursery grounds was mapped
as the 5 ppt. isohaline. This is generally regarded as the cutoff point between
the freshwater and brackish communities. Although many estuarine organisms

are euryhaline and can tolerate both freshwater and seawater, the majority
are most abundant in the salinity range from 5 to 25 ppt. Tidal movement
and flushing, a key to estuarine productivity and faunal migration, is also
more significant in waters with salinities greater than 5 ppt. This zone
includes intermediate, brackish and saline marsh types. The seaward
boundary of the nursery areas was more difficult to delineate because of the
highly indented configuration of the coastal bays. The boundary between
the inner nursery areas and the larger embayments was chosen as the sea-
ward margin of the nursery areas.'These large embayments serve as staging
areas where maturing fish or shellfish concentrate prior to their offshore
emigration. Although open water areas are utilized by estuarine dependent
forms, particularly for movements, the prime nursery is the marsh itself.
The nursery areas were also mapped on the basis of the amount of marsh-
water interface in each environmental management unit. Prime nursery areas
have a high surface acreage of marsh and a high pond density.

The Barataria Basin from the fringes of Barataria Bay northward to
near Lake Salvador represents a typical nursery area. This area is shallow
brackish marsh with numerous small ponds, lakes and bayous. This region
has a very high marsh-water interface. Movement of food, nutrients and
organisms is provided for by the ebb and flow of the tide.

The largest acreages of nursery grounds are found in environmeiiLal
management units I, IV and V in Southeastern Louisiana. In the South-
western part of the state, nursery grounds are confined to a relatively narrow
band between Chenier au Tigre and Calcasieu Pass and around Calcasieu and
Sabine Lakes.

Source of Infonnation:
Chabreck, Robert H. 1972. Vegetation, Water and Soil
Characteristics of the Louisiana Coastal Region.
Agricultural Experiment Station, Bulletin No. 664,
Louisiana State University, Baton Rouge, La.
Gaidry, Wilson J.III and Charles J. White. 1973.
Investigations of Commercially Important Penaeid Shrimp
in Louisiana Estuaries. Louisiana Wildlife and Fisheries
Commission. Technical bulletin no. 8.
St. Amant, Lyle. Louisiana Wildlife and Fisheries Com-
mission. Personal communication.

4. Public Qyster Seed Grounds
Public oyster-seed grounds are located in the parishes of Plaque-
mines, St. Bernard, Jefferson, Lafourche and Terrebonne. These are areas of
natural seed grounds in which the state has planted cultch material (generally
.clam shells) as a supplement for the production of seed oysters. All oysters
produced on these seed grounds are for the use and benefit of the oyster in-
dustry and are available to the public.

V @u$" A

5Z,

F@np

Typical shallow brackish marsh nursery grounds

Oyster seed ground reservations are located in Caillou Lake (9, 772
a cre s) in Terrebonne Parish, Hackberry Bay (4,015 acres) in Jefferson and
Lafourche Parishes, and in Bay Gardene (2,666 acres) in Plaquemines Parish.
These are areas managed by the state, with open and closed seasons for the
taking of seed oysters.

Red line" areas in Plaquemines and.St. Bernard Parishes encompass
4SO,000 acres. These are areas of natural oyster seed grounds which have
some remaining slow productive live reefs and in which clutch material is
periodically planted. Approximately 80 percent of the oysters planted on
private leases are transplanted by oyster fishermen from the sccd grounds
east of the Mississippi River. These public scod grounds (ire, Llicrofure c.,:-
tremely important to the Louisiana oyster industry which currently ranks
second nationally in volume landed.

All public oyster leases, seed ground reservations and "red line"
areas are shown on the unique ecological f eatures overlay as "oyster-1
areas.

Source of Information:
Louisiana Wildlife and Fisheries Commission. 19 7 1. Gulf of
Mexico Estuarine Inventory and Study, Louisiana.
Phase 1, Area Description and Phase IV, Biology.

S. Privately Leased Oyster Beds
There are approximately 180,000 acres of state owned water-
bottoms leased to private individuals for cultivation of oysters on private
beds. The acreage has increased in recent years as new areas have become
available for leasing. Flooding on the Mississippi River in 1973 and 1974
has driven conches and other oyster predators away from reefs that were
formerly too saline for good production. In addition, the introduction of
freshwater and nutrients from this flooding should increase production on
many of the private oyster beds.

The greatest acreage of private beds is in St. Bernard, Plaquemines ,
Terrebonne and Jefferson Parishes. All private oyster beds are shown as
oyster-2 areas on the overlay. The overlay shows boundaries around the
major oyster - producing areas. Not all areas within these boundaries are
leased. Due to the extensive number of leases and their various sizes,
each reef was not individually mapped.

Source of Information:
Tarver, Johnny. Louisiana Wildlife and Fisheries Commission.
Personal communication.

6. Live Rangia Clam Beds
Rangia cuneata is a small brackish-water clam found in low
salinity waters that possesses a unique ecological and commercial
importance. Rang is generally found in waters with salinities less than
5 ppt. These clams dominate the benthic community of Lake Pontchartrain,
Louisiana's largest estuarine lake. They serve a very important role in the
estuarine food web and are a major component in the diet of many fishes,
crustaceans and waterfowl. From the economic standpoint, eight major
industrial users utilize clam shell in the manufacture of cement, glass,
chemicals, chicken and cattle feed, wallboard, lime and as fill material
for road construction and general construction. Dredging of clam shell for
commercial purposes occurs primarily in Lake Pontchartrain.

Viable populations of Rangia occur in Lake Pontchartrain, Lake
Maurepas, Lake Salvador, Lake Verret, Atchafalaya Bay, East and West
Cote Blanche Bays, White Lake, Grand Lake, Calcasieu Lake, Sabine
Refuge Pool and Sabine Lake.

Source of Information:
Center for Wetland Resources. Louisiana State University.
Baton Rouge, Louisiana
Tarver, I.W. and R.J. Dugas. 1973. A Study of the Clam;
Rangia cuneata in Lake Pontchartrain and Lake
Maurepas, Louisiana. Louisiana Wildlife and Fisheries
Commission. Technical bulletin No. 5.

7. Exposed Shell Reefs
Exposed shell reefs consist of layers of oyster or clam
shell that have accumulated to the point that they are at or above the normal
water level. These reefs are normally dead or consist of a thin crust of live
oysters on top of layers of oyster shell.

The most extensive reef deposits are between Southwest Pass (near
Marsh Island) to Point au Fer. This reef development is most pronounced
south of Marsh Island where numerous reefs extend in a general north to
south direction for several miles out into the gulf. Shell Keys Refuge con-
sists of about eight acres of reefs that are an important sea bird nesting area.
An extensive area of reefs exists between Marsh Island and Point au Fer
reef although these natural reefs are being dredged for commercial use and
covered with sediment deposited from the Atchafalaya River.

Many small oyster reefs. are' found in Southeastern Louisiana in the
marsh-lake-bay complexes of Plaquemines, St. Bernard, Terrebonne and
Jefferson Parishes. There is an extensive oyster reef development in Southern
Barataria Bay, although most of these reefs are at or below the water surface.

Numerous reefs are found between Baptiste Collette Pass and Grand Pass
east of the Mississippi River and in the shallow bays and lakes of the
"Louisiana" marsh north of Hopedale. These reefs are irregular in shape
although most are linear. They range in size from a few feet in diameter
up to a mile in length. Oyster reefs seldom exist as clean surfaces
because of sedimentation. Often the oyster shell of these reefs is mixed
with sand and mud or may be part of a marshy shoreline. Many of the
shoreline shell deposits in the marshes of Soutneastern Louisiana are clam
shell marking the location of Indian middens. The larger reefs that are
above the water's surface include Mitchell Key and Battledoor Reef.

Exposed shell reefs have several ecological functions. They provide
habitat and shelter for many species of small benthic fishes and invertebrates.
Larger fish, such as black drum, feed directly on the live oysters of the reefs.
The biological productivity and species diversity on these reefs is usually
much higher than bare mud or sand waterbottoms. Reefs also help to regulate
saltwater intrusion, reduce wave action on marshy shorelines and increase
sediment deposition. Many shorebirds utilize these reefs for nesting.
Fishermen find sport fishing near these reefs highly productive.

Source of Information:
Burk and Associates. Field checking by staff personnel.

U.S. Army Engineer District, New Orleans. 1974. Louisiana
Coastal Area Study (Draft). Fish and Wildlife Study of
the Louisiana Coastal Area and the Atchafalaya Basin
Floodway.

U.S. Geological Survey. 1974. Infrared photography of
coastal Louisiana. Scale 1:130,000.

8. Other Unique Wildlife Habitat

a . Sea Turtle Nesting Area in Chandeleur Islands
The Chandeleur Islands are uniquely important as a nesting
area for loggerhead sea turtles. These turtles annually return to the un-
developed beaches of these islands to lay their eggs in the sand. Although
seldom observed, the tracks of these turtles are occasionally noted where
they have crawled up the beach from the Gulf and deposited eggs in holes
dug in the sand. The Chandeleurs are one of the few remaining barrier
islands with beaches sufficiently remote for these large sea turtles to nest
undisturbed. Developments along other beaches have reduced the nesting
territory of the loggerhead making retention of these beaches in a natural
state even more important to this species. The Breton Bird Refuge, including
the main Chandeleur Island, has recently been designated as a National
Wilderness Area.

Environmental Management Unit I.

Source of Information:
U.S. Fish and Wildlife Service. 1969. Breton
Wilderness Proposal, Breton National Wildlife
Refuge, Louisiana.
U.S. Bureau of Land Management. 1975. Color Map
number 14; Undersea Features, Endangered Wild-
life and Natural Vegetation of the Central Gulf of
Mexico. Outer Continental Shelf Office, New
Orleans, Louisiana

b. White-tailed Deer Concentrations (Mississippi Delta)
Numerous deer herds are scattere,d on scrub cypress-tupelo
forest, natural levee ridges, cheniers , and in the marsh itself throughout
the coastal wetlands. Peak populations occur in the Maurepas swamp
area and in the scrub cypress-tupelo forest in western Terrebonne and
southern St. Mary Parishes. A unique population of marsh deer, Odocoileus
virginianus mcilhennyi, exists in the delta marshes at the mouth of the
Mississippi River. Approximately 150 to 200 marsh deer live on the alluvial
--ridges of the river passes. This race of deer differs from the north Louisiana
race of whitetail in being smaller, darker, with smaller inturned antlers and
larger hooves. These are adaptations to survival in the marsh environment.

Populations fluctuate with the changing conditions of the delta
habitat. Severe storms and hurricanes often temporarily decimate the
populations. In past years, numerous marsh deer from the delta were live-
trapped and transplanted to other areas of the state.

Environmental Management Unit III.

Source of Information:
Lowery, George, Jr. 1974. The Mammals of Louisiana
and its Adjacent Waters. Louisiana Wildlife and
Fisheries Commission. -
McMullan, Cecil. Refuge Manager, Delta-Breton
National Wildlife Refuges. Personal communications.

c. Black Bear - Atchafalaya Basin
The few native black bears that remain in Louisiana today
are largely confined to the heavily wooded bottomiand hardwood 'terrain of
the south central part of the state. Black bears in the coastal zone are
most numerous in the lower Atchafalaya Basin in St. Mary Parish in the
swamp north and south of Morgan City. just north of the coastal zone, in
Pointe Coupee Parish, 161 black- bears were released from 1964 through 1967.

This was part of a restocking program in which bears were transported
from Cook County, Minnesota and released near Lottie and Krotz Springs.
Other sightings of black bear in the coastal area have been near Gueydan,
Cote Blanche Island, Houma, Mandeville and Slidell.

The bottomland hardwoods and swamps of the Atchafalaya Basin,
which is the bear's prime habitat, represents probably the largest re-
maining overflow swamp in the United States. For this alone, the basin
is ecologically unique. It also has outstanding value from the wildlife
and recreational standpoint. Frequent annual flooding is the koy to the
high biological productivity and the diverse array of aquatic and tcrrestridl
life forms. The basin harbors many resident and migratory wildlife species.
Because of its near wilderness state, it supplies habitat for several animal
species which are becoming less common throughout the southeastern
United States. A diverse array of wildlife occurs including black bear,
white-tailed deer, turkey, grey and red fox, grey and fox squirrel, swamp
and cottontail rabbit, numerous other fur animals such as the beaver,
raccoon, mink, otter, nutria, muskrat and bobcat, many nongame animals
such as armadillo, weasel and smaller rodents, migratory waterfowl, and
other birds including wading and shore birds, songbirds and raptors, and
reptiles including alligators and amphibians. Sport and commercial fishing
is a big activity in the basin. Dominant fishes present in the basin include
black bass, warmouth, bluegill, redear sunfish, black crappie, several
species of catfishes and bullheads, gar, buffalo, carp and bowfin.

Environmental Management Unit VI.

Sburce of Information:
Herring, -Joe, 1962. Black Bear in Louisiana.
Louisiana Conservationist, January, 1962.
Lowery, George, Jr. 1974. The Mammals of Louisiana
and its Adjacent Waters. Louisiana Wildlife and
Fisheries Commission.
U.S. Army Engineer District, New Orleans. 1974. Fish
and Wildlife Study of the Louisiana Coastal Area and
the Atchafalaya Basin Floodway. Draft Louisiana
Coastal Area Study.

d. Red Swamp Crayfish - Atchafalaya Basin
The red swamp crawfish, Procambanis clarkii is the basis
for a unique south Louisiana fishery with an annual harvest of over 10
million pounds. This fishery is valued at approximately $5 million and is
centered in the Atchafalaya Basin where over half of the crayfish are
harvested. The red swamp crayfish inhabits the shallow waters of lake
edges, bayous, ponds, ditches, marshes, swamps and other overflow lands

in fresh to slightly brackish water. In the basin, the crawfish harvest
is centered north of Morgan City around Belle River and Pierre Part.
Crawfish play a vital ecological role as a major food source for not only
humans but also for many fish and other animals such as grackles, wading
birds, ducks, frogs, turtles, snakes, raccoon, mink and otter. In turn,
crayfish feed on a wide variety of organic materials and are useful in wood
control, particularly alligator weed.
Environmental Management Unit VI.

Source of Information:
U.S. Army Engineer District, New Orleans. 1974.
Fish and Wildlife Study of the Louisiana Coastal
Area and the Atchafalaya Basin Floodway. Draft
Louisiana Coastal Area Study.

e. Roseate Spoonbill - Sabine Refuge
The roseate spoonbill, L@ ajaia is a unique bird resident
to the southwestern Louisiana prairie marshes of Cameron and Vermilion
Parishes. The spoonbill is unique because of its pink and white color,
spoon-shaped bill and long legs. The only confirmed nesting sites in
Louisiana are Rabbit Island in Calcasieu Lake (where 10 breeding pairs
were noted in 1975) and Lacassine Refuge. These Louisiana colonies are
the northernmost for the species. Spoonbills in Louisiana do not migrate
and remain in the southwestern marshes all year. Although classified as un-
common on the Sabine Refuge, populations have made a strong comeback
in Cameron and Vermilion parishes. On the 1972 Christmas Bird Count,
the Sabine Refuge had 252 birds.

Environmental Management Unit VIII and IX.

Source of Information:
Lowery, George H. Jr. 1974. Louisiana Birds.
Louisiana Wildlife and Fisheries Commission.
Louisiana State University Press.
U.S. Fish and Wildlife Service. 1975. Wading Bird
Rookery Survey in Louisiana.

f. Big Burn - Deep Peat Burn Near Creole
Between the Intracoastal Waterway and Little Chenier east
of Louisiana Highway 27 is an area of deep freshwater marsh that is called
the Big Burn. This area, consisting of intermittent ponds and broken
marsh, was created by a marsh fire that burned much of the peat deposits
down to the clay pan. This burn created ponds and lagoons which are
gradually being revegetated by cattail, bullwhip, bulltongue, alligator weed,

coffee bean and white water lily. Owne d by the Miami Corporation, this
area is unique because of the excellent fresh water fishing that has been
created by the burn. Many of the other lakes in the freshwater marshes
of the area were created as the result of deep peat burns.

Environmental Management Unit VIII.

Source of Information:
Burk and Associates. 1976. Field investigation by
staff personnel.
Chabreck, Robert H. Wildlife Biologist, U.S. Fish
and Wildlife Service. Personal communication.
O'Neil, Ted. 1949. The Muskrat in the Louisiana
Coastal Marshes. Louisiana Wildlife and Fisheries
Commission.

g. American Oil Company Waterfowl Impoundment
South of Gueydan
This area consists of approximately 10 square miles of
freshwater marsh on the northwestern shore of White Lake in Vermilion
Parish. Impounded by the American Oil Company, the area is managed
for waterfowl hunting. Water levels are regulated by a series of dikes
and control structures. Water levels are lowered so that annual plants
such as wild millet and wild rice may germinate. When water levels are
raised, these highly desirable waterfowl food plants then become acces-
sible to waterfowl. This area annually holds a very large body of ducks.
Due to this water level manipulation, plant species composition of the
area differs from the surrounding marshes which are all within the
Mermentau Basin system.

Environmental Management Unit VIII.

Source of Information:
Chabreck, Robert H. Wildlife Biologist, U.S. Fish
and Wildlife Service. Personal communication.

h. Peak Duck Concentrations
Coastal Louisiana's marshes, swamps and rice fields con-
stitute the largest and one of the most important waterfowl wintering areas
in the United States. Coastal Louisiana is at the southern terminus of the
Mississippi Flyway and normally winters between 5 and 6 million ducks.
Additional millions of ducks use the Louisiana marshes for staging, resting
and feeding before continuing across the Gulf of Mexico to. wintering
grounds in Central and South America. Thirty species of ducks have been

recorded in Louisiana and five of these nest here. The mottled duck,
fulvous tree duck, and the wood duck breed in significant numbers with
the blue-winged teal and hooded merganser in lesser numbers.

Ducks do not blanket the entire coastal area but tend to concen-
trate in areas with preferred foods and proper water levels. Fresh and
intermediate marshes I to 6 inches deep produce the prime habitat
conditions. The production of preferred waterfowl foods, such as wild
millet, smartweed, cyperus, three-cornered grass, wild rice, delta
duck potato, bulrush, spikerush, pondweeds and wild celery, is higher
in fresh and low salinity marshes. Saline marshes are generally of little
value to ducks because they don't produce preferred foods. Ducks will
shift between feeding and resting areas depending on highly variable
local food and water conditions. Although conditions may change from
year to year, there are certain areas that attract. peak duck concentrations.
Under normal conditions, duck populations are greater in Southwest
Louisiana because of more preferred habitat. Twenty eight of ffiese areas
have been shown on the overlay. It should be noted that the symbols
used to represent duck concentrations on the overlay indicate general.
areas of concentration and do not imply ducks are not to be found in other
areas. The following locations are areas, year in and year out, that
normally concentrate ducks.

Louisiana Coastal Areas Attracting
Peak Duck Concentrations

Location Parish
1. Black Bayou Area Cameron
2. johnsons Bayou Area Cameron
3. Sabine Refuge Cameron
4. Lacassine Refuge Cameron
5. Grand Chenier to Grand Lake Area Cameron
6. Rockefeller Refuge Cameron, Vermilion
7. Nearshore Gulf waters
8. Nearshor6 Gulf waters
9. American Oil Co. Impoundment Vermilion
10. North of White Lake Ven-nilion
11. South of Pecan Island Vermilion
12. Rainey and State Refuge Vermilion
13. Marsh Island Refuge Iberia
14. West of Wax Lake Outlet St. Mary,
15. West of Lower Atchafalaya River St. Mary
16. Duck Lake Area of Atchafalaya Basin St. Martin
17. Lost Lake Area 'Terrebonne
18. Carencro, Bayou Area Terrebonne
19. Bayou Penchant Area Terrebonne
20. South of Lake Maurepas St. John the Baptist

Location Parish
21. Bayou Blue Area Lafourche
22. West of Lake Salvador St. Charles
23. Lake Pontchartrain (particularly near St. Tammany, Orleans
grass beds)
24. Scarsdale - Delacroix Island Area Plaquemines
25. North of Little Lake near Pearl River St. Tammany
26. Biloxi Wildlife Management Area St. Bernard
27. Delta Refuge Plaquemines
28. Pass a Loutre Public Hunting Grounds Plaquemincs

Environmental Management Units I-IX.

Source of Information:
Burk & Associates, Inc. 1976. Field investigations
by staff personnel.
Chabreck, Robert H. Wildlife Biologist, U.S. Fish
and Wildlife Service. Personal communication.
Ensminger, Allen. Head, Refuge Division. Louisiana
Wildlife and Fisheries Commiss'ion.
Personal communication.
U.S. Army Engineer District, New Orleans. 1974. Fish
and Wildlife Study of the Louisiana Coastal Area
and the Atchafalaya Basin Floodway. Draft
Louisiana Coastal Area Study.

i. Geese Concentrations
. Four species of geese winter in coastal Louisiana - Canada,
blue, lesser snow and white-frorited geese. Geese tend to concentrate
into large bodies even more so than ducks. They can be locally scarce or
abundant, often giving fake impressions of actual number of birds. Louis-
iana winters a yearly average of 390,000 geese that concentrate in
Cameron and Vermilion Parishes, the Mississippi River Delta and the outer
fringes of the marshes in St. Bernard Parish near Mississippi and Chandeleur
Sound.

Individual species concentrate in different types of habitat, based
primarily on food preferences. Canada goose populations have greatly
declined in recent years due to changes in migratory patterns. A resident
population of about 2, 000 birds still exists around and on the Rockefeller
Refuge. White-fronted geese winter in rice field areas along the Intra-
coastal Waterway from Vermilion Bay west to Texas.' Blue and lesser snow
geese are more widespread in coastal Louisiana. Concentrations occur in
the rice fields and pastures near Kaplan, Gueydan and Lake Arthur, near
johnsons Bayou, Sabine Refuge, in the brackish marshes of State and Marsh

Isla nd Refuges and along the north shore of Vermilion Bay, in the lower
Terrebonne Parish marshes , north of Little Lake near the mouth of the
Pearl River, in the brackish and saline marshes bordering the outer fringes
of the St. Bernard sub-delta and orl the mud -flats along the passes at the
mouth of the Mississippi River. These areas of geese concentration are
shown on the overlay. Louisiana's coastal marshes are critical wintering
habitat, particularly for blue and lesser snow geese. The majority of the
continental population of these geese winter in the marshes and rice
fields of coastal Louisiana and southeastern Texas.

Environmental Management Units I,III, V, VII, VIII and IX.

Source of Information:
Burk & Associates, Inc. 1976. Field investigations by
staff personnel.
Chabreck, Robert H. Wildlife Biologist, U.S. Fish
and Wildlife Service. Personal communication.
U.S. Army.Engineer District, New Orleans. 1974. Fish
and Wildlife Study of the Louisiana Coastal Area
and the Atchafalaya Basin Floodway. Draft
Louisiana Coastal'Area Study.

Os2rey Nest
The osprey (Pandion haliaetus is a threatened species that
is an uncommon resident of the Louisiana coast. Only one nest of the
osprey has ever been observed in the state. It was discovered by
Mac Myers about one mile northwest of Venice on March 30, 1974. Ospreys
have been recorded in the state in every month of the year, although the
greatest number of records fall in April, September and December.

Environmental Management Unit IV.

Source of Information:
Lowery, George H. fr. 1974. Louisiana Birds. Louisiana
Wildlife and Fisheries Commission.

9. Unique Fishery Habitat - the Barataria Basin
The Barataria Basin (Environmental Management Unit IV) is
the most productive Louisiana estuary. It is located in the center of the
"Fertile Fisheries Crescent" considered to be one of the most productive
fisheries regions on earth. Barataria Bay and surrounding marshes are
responsible for nearly half of the fisheries harvest on the Louisiana coast,
which annually leads the nation in fishery harvest. With the exception of
Gulf menhaden which are harvested in offshore and nearshore waters, it is

the most productive bay system in total finfish and shellfis h harvest.
More croakers, black drum, red drum, gar, spotted and sand seatrout,
crabs, shrimp and oysters are taken from this basin than any other on the
Louisiana coast. Many of the fish that are dependent on its marshes as
a nursery ground are harvested in nearshore Gulf waters. From 1968 to
1970, the average annual fisheries harvest from the Barataria Basin was
20.2 million pounds. This phenomenal productivity is due to the input of
nutrients and freshwater from the Mississippi River, a subtropical climatic
regime, abundant rainfall, cycling of nutrients, minerals, and organic
detritus by tidal flushing, high rates of plant production, and a high ratio
of marsh to water. The bay has a highly irregular and indented shoreline con-
sisting of many marshy islands, small lakes, ponds and bayous. This is
the ideal configuration for estuarine productivity because there is a large
zone of marsh-water contact. This interface zone between marsh and
water supports higher fish biomass due to the higher availability of detritus
and small invertebrate food organisms.

Source of Information:
National Marine Fisheries Service. Fisheries
Statistics .
Lindall, W.N. et.al. 1971. Louisiana coastal zone:
analysis of resources and resource development
needs in connection with estuarine ecology.
Section 10 - Fishery Resources. Report of the
Comm. Fishery Work Unit, Nat. Mar. Fish. Serv.
Biol. Lab. , St. Petersburg, Fla.
Wagner, Paul R. 1973. Seasonal Biomass, Abundance,
and Distribution of Estuarine Dependent Fishes
in the Caminada Bay System of Louisiana. Ph.D
dissertation. Louisiana State University, Baton
Rouge, Louisiana.

TANI AL

.B. BOTANICAL FEATURES

if Unigue Botanical S2ecimens or Communities

There are 21 areas of unique botanical importance on the
Louisiana coast that represent rare occurrences of certain plants, specimens
of unusual size (State'Champion Trees),'or outstanding natural plant com-
munities of special aesthetic, scientific or ecological significance. These
specimens or communities are listed in the following table.

Environmental
Earis Manaciement Unit Name /Description

1. Vermilion VIII Canna glauca, a rare plant just
east of Highway 82.south of Forked
Island

2. St. Martin VI Atchafalaya floodway natural area
St. Mary and overflow swamp. A second
Assumption growth cypress swamp with some
original cypress and tupelo gum trees.
Extremely productive habitat support-
ing dense populations of terrestrial,
avian and aquatic fauna.

3. Terrebonne V Swamp loosestrife, Decodon
verticellatus, a rare shrub found in
the marsh north of Houma

4. St. James IV Oak Alley, a famous. row of oaks

S. Livingston Blind River swamp and natural area,
Ascension an abandoned Mississippi River dis-
St. James tributary about 20 miles in length
containing about 25,000 acres of
cypress-tupelo gum forest. Affected
by ebb and flow of tides through Lake
Maurepas., this swamp supports a very
rich and diverse faunal community.

6. Livingston Amite River Natural Area. Example of
a river bank swamp.

7. Livingston Clio cypress swamp community,
possibly virgin trees.

Environmental
Parish Management Unit Name/Description

8. Livingston I Largest living specimen of the Laurel
oak, Quercus laurifolia, located on
the northwestern shore of Lake
Maure pas, c ircumfercnce 20' 4".

9. Livingston I Tickfaw River Natural Area. River
bank swamp similar to Amite River.

10. Livingston I Dense stands of Spruce pine, Pinus
Tangipahoa. qlabr , occur along streams in this
area which is the western limit of its
range.

11. Tangipahoa I Ponchatoula Marsh, a freshwater
marsh with a cypress swamp border.
Panicum hemitomum with Typh , I
Sagittaria and Pontederia forms a
thick mat over what was probably a
former lake bed. Proposed for natural
landmark status, 1971. Estimated
4000 acres.

12. Jefferson IV State Champion hackberry, Celtis
laevigata, circumference 19' 2 ".

13. Jefferson IV Avondale virgin swamp community.

14. Jefferson IV Oak tree, largest living specimen in
the state, circumference 22' 2". Near
Mississippi River in Kenner.

15. St. Tammany I State Champion Live Oak, Quercus
virginiana, called the Seven Sisters
oak. Located near Mandeville north
of Lake Pontchartrain. Circumference
3711".

16. St. Tammany I Saw Palmetto, Serenoa re2en a ra re
plant in Louisiana found along Bayou
Lacombe.

17. Orleans I Duelling oaks in New Orleans, scene
of many duels.

Environmental
Parish Management Unit NameZDescription

18. Orleans I Pakenham Oaks near Chalmette
Battle ground.

19. Orleans I Saw Palmetto, Serenoa re2en a
rare plant found.along Chef Menteur
Pass.

20. St. Tammany I Pearl River bottomlands, dense
stands of Spruce Pine and paiiiietto.

21. St. Tammany I Honey Island Swamp, excellent
example of a cypress-tupelo gum
river overflow swamp of about 5,760
acres. Area remains in its natural
state and is bisected by several tri-
butaries of the Pearl River. Supports
high populations of deer, turkey,
squirrel, feral pigs, smaller furbearers,
wood ducks and many species of fresh-
water fish , molluscs, and crustaceans.

Source of Information:
Engineer Agency for Resources Inventories. 1973.
Inventory of Basic Environmental Data, South
Louisiana. Prepared for U.S. Army Corps of
Engineers, New Orleans District.

2. Submergent Grass Beds
Submergent beds of marine grasses are an extremely important,
although relatively small, component of the Louisiana coastal ecosystem.
These benthic grasses grow in shallow, relatively clear and protected waters
with predominantly sand bottoms. There are seven areas in Louisiana
coastal waters where habitat conditions are favorable for the establishment
of submergent marine grasses. These areas are centered around Terrebonne
Bay, Lake Pontchartrain and the Chandeleur Islands. Barataria Bay lacks
many of these grasses but has a seasonal community of benthic marine algae.
The generally turbid waters and soft bottom of most of Louisiana's estuaries
are the primary limiting factors to more widespread distribution. The seven
areas where submergent marine grasses occur are in the following locations.

1) Bay side of Isle Dernieres, Timbalier and East Timbalier Islands
2) Along the north shore of Lake Pelto, Old Lady Lake and the
southeastern shore of Timbalier Bay

3) Western side of the main Chandeleur Islands from North
Point westward to Freemason and North Islands and south toward Curlew
Island
4) Southwestern corner of Lake Salvador in Temple and
Catahoula Bay
5) Northeastern corner of Lake Catherine
6) Northeastern shore of Lake Pontchartrain between Green
Point near Mandeville and Big Point near Slidell (approximately 2000 acres)
7) North Pass between Lakes Maurepas and Pontchartrain.

Two basic communities of submergent grasses occur in these areas.
A marine community of grasses including turtlegrass, Thalassia testudinum
shoalgrass, Halodule wrightii manateegrass, Cymodocea manatorum; Gulf
Halophila, Halophil en@jelmannj; and Syringodium, Syringodium filiforme
occurs on the back side of the islands in Terrebonne and Timbalier Bay
and on the western side of the Chandeleurs. Shoalgrass and manateegrass
are the predominant species in the Terrebonne Bay area. A brackish water
.community of grasses including wild celery, Vallisneria americana,
widgeongrass, Ruppi maritima and Southern naiad, Naias quadalupensis;
occurs in Lake Salvador, Lake Catherine and Lake Pontchartrain. Horned
pondweed, Zanichellia palustri , is found in North Pass. These species,
especially widgeongrass, also occur in abundance in small brackish water
ponds and lagoons but no attempt was made to map this distribution.

These submergent grass beds have many important ecological
functions and roles in the coastal ecosystem and are a component of
special value. The true value of submerged grass communities is not
fully understood and is generally underestimated. They supply food to
grazing animals , detrital material and nutrients to the water,' add oxygen
to the water through photosynthesis and stabilize bottom sediments by
increasing sedimentation of suspended sediments. This latter function is
often responsible for waters being clearer over the top of grass beds. They
provide nursery areas and refuge for the young of many fishes and small
invertebrates and attract a diverse and prolific epiphytic biota, often creat-
ing unique habitat for the existence of certain species. Marine grass beds
are also extremely productive, -in some cases about as productive of de-
trital nutrients as salt marshes.

Environmental Management Units I, IV and V.

Source of Information:
Burk and Associates, Inc. 1976. Field checking by
staff personnel.
Clark, John. 1974. Coastal Ecosystems. The Conserva-,
tion Foundation, Washington, D.C.

Hass, Sue. 1975. Biologist, U.S. Army Corps of
Engineers, New Orleans District. Environmental
Quality Section. Personal communication.
Montz, Glen N. 1975. The Submerged Vegetation of
Lake Pontchartrain, Louisiana. U.S. Army Corps
of Engineers, New Orleans District. Environmental
Quality Section.
Thayer, Gordon W., Douglas A. Wolfe and Richard B.
Williams. 1975. The Impact of Man on Seagrass
Systems. American Scientist, 63 (3): 288-296.
University of Southwcstern Louisiana. 1972. U.S. L.
Studies on the Chandeleur Islands, Research Series
No. 10. Edited by H.D. Hoese and J.M. Valentine,
Jr.
U.S. Geological Survey. 1974. Infrared photography of
coastal Louisiana, Scale 1:130,000.

3. Black Mangrove Areas (Avicennia nitida)
The occurrence of black mangrove in coastal Louisiana is
ecologically unique because it represents the northernmost point in the
range of this species. This small evergreen shrub occurs near the southern
margins of Lake Pelto, Terrebonne Bay, Timbalier and Barataria Bay on the
west side of the Mississippi River and from Carencro Bay northward to the
Mississippi River Gulf Outlet and the main Chandeleur Island east of the
river. It is most commonly found on the edges of small islands in southern
Barataria, Terrebonne and Timbalier Bays. In some areas, such as Calumet
Island in Timbalier Bay, it covers the entire island. It is limited to these
southern margins of the bays by its requirement for high salinity and its
inability to survive frost. During cold winters, many of the plants die.
After two or three years of relatively mild winters, it grows luxuriously and
may reach five to six feet high.

Black mangrove has several ecological functions similar to marine
grass beds. It aids in shoreline and marsh stabilization by trapping sedi-
ment and reducing wave action, provides d6trital food material and supplies
shelter and substrate for many small fishes and invertebrates. Many small
animals such as periwinkles, mussels, fiddler crabs, mud crabs, small.
blue crabs and hermit crabs find shelter and food in and on the pneumato-
phores (subaerial roots) of the mangroves. Mangrove fruits are transported
long distances by tidal currents and often colonize bare mudflat areas or
exposed marsh shorelines thus helping to reduce marsh erosion and land
loss. It is also used extensively by many wading and sea birds, including
the brown pelican, for nesting and roosting habitat.

Environmental Management Units 1, 11, IV, and V.

Source of Information:
Burk and Associates, Inc. 1976. Field checking by
staff personnel.
Gagliano, S.M. et.al. 1973. Environmental Atlas and
Multiuse Management'Plan for South-Central
Louisiana. Hydrologic and Geologic Studies of
Coastal Louisiana. Report 18, Volume 2. Center
for Wetland Resources, LSU. Baton Rouge, La.
U.S. Geological Survey. Infrared photography of
coastal Louisiana. Scale 1:130,000.

4. Bottomland Hardwoods
Bottomland hardwoods are considered to be the prime forest
game habitat for the most popular sport species of wildlife as well as for
certain rare or endangered species. In coastal Louisiana, bottomland hard-
wood habitat is most prevalent in the upper Atchafalaya Basin and Pearl
River Basin (see overlay).

The alluvial ridges of the Mississippi River's deltaic plain were
once dominated by bottomland hardwoods. Today, most of these ridges and
natural levees have been cleared for agriculture and urbanization. Remaining
hardwood forests are located on the flanks and distal ends of the alluvial
ridges.

The dominant trees of bottomland hardwoods are live oak, water oak,
willow oak, nutall oak, overcup oak, Shummard oak, white oak, cherrybark
oak, bitter pecan, green ash, redgum, willow, sycamore, hickory, cotton-
wood, hackberry, American elm,black and water locust. These species com-
prise various successional and climax communities, depending on elevation
and degree of annual flooding that may occur. These forested areas of mixed
hardwoods provide the best habitat and game range for white-tailed deer,
turkey, black bear, squirrel and many other small mammals, fur animals and
many songbirds. The ideal hardwood game range is one that is comprised of
the maximum variety of tree species of all age classes. Oaks and hickory
produce high quality acorns and mast for forest game on a year-round basis.
Bottomland oaks sustain higher mast yields than upland oaks. In both the
Atchafalaya and Pearl River Basin, cypress-tupelo brakes and sloughs inter-
mingle with the hardwood forest. This creates an alternating hardwood ridge
and cypress swale pattern that provides a good and varied food supply and
escape cover.

Environmental Management Units I and VI.

ALI

elk-

1p,

:11, A",
IN 5
JW

Black Mangrove on small island in Timbalier Bay

Source of Information:
Brown, Clair A. 1965@ Louisiana Trees and Shrubs.
Louisiana Forestry Commission, Bull. No. 1.
U.S. Army Engineer District, New Orleans. 1974. Fish
and Wildlife Study of the Louisiana Coastal Area and
the Atchafalaya Basin Floodway. Draft Louisiana
Coastal Area Study.
U.S. Geological Survey. 1974. Infrared Photography of
coastal Louisiana. Scale 1:130,000.

E L AL
FEAT E

'Ok

C. GEOLOGICAL FEATURES

1 Barrier Islands and Beaches
Barrier islands on the Louisiana coast represent relicts of
abandoned deltas of the Mississippi River. These elongate islands charac-
teristically have a smooth sandy beach on the Gulf side and a highly in-
dented shoreline with black mangrove and salt marsh on the protected bay
side. Several complexes of barrier islands are found along the coast. The
major island groups are: Isle Dernieres; Timbalier - East Timbalier; Grand
Isle - Grand Terro; and tho Chandelcur Island chain.

Barrier islands are constantly changing shape and form in response
to wave action, tidal and longshore currents, sediment supply and storms.
A pattern of continual erosion and deposition constantly shapes and re-
shapes the islands. Of foremost importance in the maintenance of a stable
ecology is the frontal sand dunes and the mangrove and salt marsh on the
back side of the islands. These features stop storm waves from breaching
the islands and catch sediment thus holding the shore intact. Vegetation,
such as baccharis , wax myrtle and rattle box, helps to stabilize the dunes.
Dunes on most of the Louisiana barrier islands are 3 to 6 feet high. On some
of the islands, such as Grand Isle, oak trees help to stabilize the island.

Barrier islands are extremely important in regulating and maintaining
water exchange and salt water balance between the Gulf and the bays.
Between the islands are tidal passes through which water exchange between
the Gulf and bays occurs. The islands help reduce storm surge and wave
action on the marshes in the bays behind the islands. They are also prime
nesting and roosting areas for many shorebirds and sea birds. Other rare or
endangered wildlife, such as brown pelicans and loggerhead sea turtles
utilize the islands. The salt marsh and mangrove on the back side of the
islands serve as nursery and feeding grounds for many fish and shellfish.
The barrier islands also have a high recreational potential and value. Many
people utilize them for fishing, camping, swimming, nature photography or
beachcombing. The lack of accessibility helps maintain some of the
islands in a semi-wilderness state. The Breton Bird Refuge, including the
main Chandeleur Island and South Breton Island, has recently been included
in the National Wilderness Preservation System and is Louisiana's only de-
signated wilderness area.

A brief listing of the major barrier islands and beaches on the
Louisiana coast follows. Those areas have been divided into seven groups.

1) Sabine Pass to Southwest Pass. This area includes a continuous
thin band of sand and or mud beach that is part of the mainland and not
separated as the true barrier islands. Included are Ocean View Beach, Con-
stance Beach, Peveto Beach, Holly Beach, Rutherford Beach and Cheniere

au Tigre. From Cheniere au Tigre to Point au Per, mud beaches predominate
due to sediment deposition from the Atchafalaya River.

2) Point au Per to Bay junop. Small narrow sand and shell beach.

3) Isle Dernieres from Raccoon Point to Wine Island Pass. Beachos
of fine sand approximately 100 feet wide backed by dunes rising 3 to 5 feet.
These islands separate Lake Pelto from the Gulf, run east to west and are
approximately one half mile wide and 24 miles long. They are broken by
several channels.

4) Timbalier - East Timbalier Islands. Separate Terrebonne and
Timbalier Bays from Gulf. Same approximate dimensions as Isle Dernieres,
Timbalier Island is 9 miles long and East Timbalier is about 9.5 miles long.
The two islands are separated by Little Pass Timbalier.

5) Grand Isle Grand Terre Islands. Separate Barataria Bay from
Gulf. These islands are separated by Caminada Pass, Barataria Pass, Pass
Abel and Four Bayous Pass. Grand Isle extends ab 'out 7. 5 miles in a north-
east to southwest direction and is about three quarters of a mile wide at the
center. The beach is up to 300 feet wide but averages 50 feet wide and is
composed of fine sand and shell fragments. Grand Terre is split into two
islands., the larger being approximately 3 miles long and three quarters of
a mile wide. The smaller island is about 2.5 miles long and much narrower.
Similar topography to Grand Isle except without trees.

6) Lanaux - Pelican Island. These are not true barrier islands but
narrow sand beaches between Bastian and Shell Island Bay and the Gulf.
Narrow sand and-mud beach.

7) Chandeleur Islands including North and South Breton Island,
Grand Gosier Island, Errol Island, North Islands, New Harbor Islands, and
the main Chandeleur Island complex. The Chandeleurs are truly a unique
area in Louisiana and closely resemble coastal Florida with its clear high
salinity waters, sand beaches, black mangrove and turtle grass shoals.
They are unlike most of Louisiana's coast,which is characterized by turbid
low-salinity waters and highly organic substrate. These islands form a
North-Southarc approximately 20 miles off the coast and mark the eastern
end of the old St'*Bernard delta system. They are approximately 50 miles
long from the North Point of the Chandeleurs to the West Point of Breton
Island. Within the arc, a few miles to the west, lie North Islands, New
Harbor Islands and Freemason Island. The Smack Channel area between
New Harbor Islands and the main Chandeleur Islands is an extremely unique
area. It possesses a rich and diverse fauna of certain small crustaceans
molluscs, invertebrates and fishes that represent a combination of temperate
Northern Gulf species and tropical West Indian species. Many species are

-77

k" IV

zz
wo If'

74"
wow"

Sand beach near Bay Marchand

endemic to the grass beds around North Islands. The islands are composed
of fine quartz sand and shell beaches on the Gulf side and mangrove and
salt marsh on the sound side. The beaches are backed by low sand dunes.
The oldest and largest dunes are colonized by dense thickets of baccharis
and wax myrtle.

Environmental Management Units I, IV, V, VII, VIII and IX.

Source of Information:
Burk and Associates, Inc. 1976. rield investigation by
staff personnel.
U.S. Army Engineer District, New Orleans. 1974. Fish
and Wildlife Study of the Louisiana Coastal Area and
the Atchafalaya Basin Floodway, Draft Louisiana
Coastal Area Study.

2. Deep Migratga Tidal Passes -
Deep tidal passes connecting the estuaries and the Gulf of
Mexico are ecologically important as migratory pathways for many estuarine
dependent fish and shellfish. Post larval and adult forms of many marine
and estuarine species immigrate in and emigrate out of these passes at
certain seasons of the year. In the spring and summer, there is a large
inshore migration of larval and post larval shrimp, crabs, and fishes that
ride tidal currents through the passes towards the upper ends of the estuarine
basins. In the fall, these same species migrate back out through these
passes into the Gulf for spawning and overwintering after utilizing estuarine
waters as nursery grounds. Because of tidal scouring and high volumes of
water movement, the passes are often 50 to 100 feet deep.

Through these deep passes, nutrients, detritus and sediments
derived in the inshore bays are exported into the Gulf where they provide
food for the marine food web. Phytoplankton, the basis of the marine food
web, flourish on the nutrients supplied by decomposition of marsh grasses
and land drainage. Many large marine fishes enter the passes and lower
portions of the bays on feeding forays. Tidal currents, on which all life
in the estuaries depend, ebb and flow through the passes. Deep tidal passes
are therefore vital to the maintenance of both inshore and nearshore fisheries
productivity.

Although the Louisiana coast has a highly irregular shoreline and
many connections between the bays and Gulf, the deeper passes are the
most important migratory pathways. The following 25 passes are the most
significant in terms of fishery migration and tidal movements. Most of these
passes are located between the Gulf and the lower ends of the bays or large
inshore lakes.

1) Sabine Pass
2) Calcasieu Pass
3) Rollover Bayou
4) Southwest Pass (near Marsh Island)
5) Oyster Bayou
6) Bayou Grand Caillou
7) Grand Pass des Ilettes
8) Whiskey Pass
9) 'Wine Island Pass
10) Cat Island Pass
11) Little Pass Timbalier
12) Belle Pass
13) Caminada Pass
14) Barataria Pas.s
15) Pass Abel
16) Quatre Bayou' Pass
17) Mississippi River Gulf Outlet
18) Deep Pass
19) Grand Pass
20) Three Mile Pass
21) Nine Mile Pass
22) Le Petit Pass
23) Rigolets
24) Chef Menteur Pass
25) Industrial Canal at the Seabrook Bridge

Environmental Management Units: I, IV, V, VI, VIII and IX.

Source of Information:
Burk and Associates, Inc. 1976. Field investigation by
staff personnel.
U.S. Geological Survey. Topographic maps of various
dates and scales.

- ------ --- ----

Barataria Passm deep tidal pass connecting

Barataria Bay and Gulf of Mexico

4AP,

Am' 1w

!71
@'7

Live Oaks on Little Chenler ridge

3. Cheniers and Beach Rid2es
Cheniers and beach ridges are linear geological features unique
to a deltaic coast such as Louisiana. They represent ancient Gulf beaches
that were stranded by deposition of alluvial sediments Gulfward from the
former shoreline by deltaic sedimentation. The cheniers lay in parallel
belts to the Gulf and are composed of sand and shell ridges and dunes de-,
posited by wave action. Cheniers furthest inland represent the oldest
cheniers while those closest to the Gulf are youngest. Cheniers were formed
by the constant shifting of the Mississippi River across its flood plain. This
resulted in alternating erosion and deposition and construction of cxtcnsivo
mud flats and marshes which,presently separate the- cheniers. When the
Mississippi shifted eastward, the process.was reversed from build-out to
retreat and beaches were formed by wave action on marshy shorelines. These
beaches became stranded when the river shifted its discharge to the west side
of its flood plain again. Mos t are 4 to 5 feet above sea level.and are
lined with large old live oaks (Que rcus virginiana). The cheniers reach maximum
elevations of about 10 feet above the marsh and a maximuffi width of about a
quarter mile. Chenier is a French word meaning "place of oaks " and the oak
trees are visually the most outstanding feature of the cheniers.

The cheniers are the most distinct topographic feature of the Chenier
Plain in Southwestern Louisiana. They are located from near Sabine Pass
eastward to Cheniere au Tigre. The largest include Blue Buck Ridge., Smith
Ridge, Front Ridge, Back Ridge, Hackberry Beach, Oak Grove Ridge, Little
Chenier, Pumpkin Ridge, Eugene Island, Grand Cheniere Ridge, Cheniere
Perdue, Pecan Island, Mulberry Island, Bill Ridge and Cheniere au Tigre.
These cheniers and smaller cheniers are shown on the overlay. In many
cases where subsidence has occurred and marsh deposits have built up, the
marsh'ridges may be only a foot or two above the marsh and are discernable
by the presence of rattle box or roseau ca ne.

The name cheniers have also been given to abandoned natural levees
(e.g. Bayou Grande Cheiniere) and beach ridges (e.g. Cheniere Caminada)
in Southeastern Louisiana. Although these "chenieres" have a similar
appearance and vegetation, they. were formed differently from. the cheniers
of Southwestern Louisiana.

Ecologically, the cheniers and beach ridges serve an important
function as wildlife habitats, storm barTiers, and in limiting salt water in-
trusion into the marshes. This is particularly evident along the Grand
Cheniere-Pecan Island ridge- complex. Marshes south of these chenieres
are brackish while marshes to the north are primarily fresh. The cheniers
are very important as resting areas for birds completing trans-Gulf migra-
tions. They also have high recreational value for camping, hiking, bird-
watching and picnicking.

Environmental Management Units: IV, VIII and IX

Source of Information:
Howe, Henry V. , et.al. 1935. Geology of Cameron and
Vermilion Parishes. Geological Bulletin No. 6.
Department of Conservation. La. Geological Survey.
U.S.G.S. 1974-. Infrared photography of.coastal Louisiana.
Scale 1:130,000.

4.. Salt Domes
Salt domes are prominant geological features around which most
of the oil and.gas drilling in South Louisiana occurs. Most are subsurface
in both the 'coastal marshes and offshore areas. Of the many domes on land
in South Louisiana, only the "Five Islands" in Iberia and St. Mary Parishes
are truly conspicuous. Four of these islands occur within. the coastal zone
-Avery Island, Weeks Island, Cote Blanche Island and Belle Isle. These.
domes are spaced at 7 to 9 mile intervals along a line of geologic activity.
They are round with diameters of approximately two miles.

Called "islands" because they represent areas of significant' topo-
graphic relief surrounded by near sea level marshes, the salt.domes are
unique from a geological, botanical, zoological, historical and archeological
-standpoint. They reach elevations of up to 152 feet above sea level creating
quite a striking vista as they seem to "rise" up suddenly out of the marshes.
The abrupt change in elevation from sea level to over 150 feet is unique in
coastal Louisiana where changes in elevation of only a few inches often
cause botanical differences. The islands are heavily wooded and have
numerous small ponds and lakes.. The dom(@s have a distinct flora and fauna
quite different from the surrounding marshes. Vegetative types range from
marsh to upland hardwoods. The dominant trees on the well drained areas
of the domes are bitternut hickory, pecan, pignut hickory, southern magnolia
and live oak. Many other species of lowland hardwoods, shrubs, vines,
herbs, grasses, fems, liverworts and mosses are found. Some of the
mosses have a very disjunct range being found only in tfopical America,
Florida and on the Five Islands. The islands are also important wading bird
rookeries and habitats for white-tailed deer, small mammals and occas-
sional black bears. From the archeological standpoint, eva-cuations on
Avery Island have revealed evidence of the earliest records of man in coastal
Louisiana.

Environmental Management Units VI and VII.

Source of Information:
Kniffen, Fred B. 1968. Lotiisiana, Its Land and People.
Louisiana State University Press.

U.S., Army Corps of Engineers, Vicksburg District, 1973.
Report on Gulf Coast Deep Water Port Facilities,
Texas, Louisiana, Mississippi, Alabama, and
Florida. Appendix F. Environmental Assessment,
Central Gulf.

5. Mud LuWs
The mud lumps are small mud islands unique to the mouths of
the Mississippi River passes. Mud lumps are found near the ends of South-
west Pass, South Pass, Southeast Pass and Pass a Loutre. They range up
to twelve feet in height and vary in diameter from a few square feet to
twenty acres. They are produced by geological processes occurring at river
mouths and consist of mostly bowed-up sediments of sandy silts and clay.
The mud lumps are formed by the upward thrusting of fine clays between
heavier coarser sediments being deposited on bars at the mouths of the river
passes. The clay is forced upward through overlying materials and may
emerge rapidly like a small volcano, spewing marsh gas and mud. Small
mounds are formed that usually are eroded by wave action within 15 years.
The action of waves and uplift on the mounds may produce features such as
cliff faces and step-like terraces. In addition to being unique geological
features,the mud lumps are important bird nesting areas.

Environmental Management Unit III.

Source of Information,
Kniffen, Fred B. 1968. Louisiana, Its Land and People.
Louisiana State University Press.

6. freshwater Impoundments in the Marshes
There are four areas within the coastal marshes that have been
impounded for waterfowl management or water supply. Freshwater pools
have been created by leveeing off natural marsh in which water levels are
manipulated by pumping or control structures. Although natural marshland
processes have been somewhat altered, productive waterfowl and fishing
areas have been created. Two of these impoundments are on refuges in the
prairie marshes of Southwestern Louisiana, another is in the saline marshes
of lower Barataria Bay and the fourth is in the delta marshes near the mouth of
the Mississippi River. Other impoundments are found on Marsh Island and
Rockefeller Refuges, but these are brackish water types. A description of each
freshwater impoundment follows.

1) Sabine Refuge Pool. This area, along with two other smaller
pools, consists of 34,000 acres of freshwater marsh. The area is heavily
utilized as wintering and nesting habitat by many species of waterfowl,
shorebirds and wading birds,and also provides good to excellent freshwater
fishing. 35

2) Lacassine Refuge Pool. This pool consists of 16,000 acres
and serves as a roosting and feeding area for peak populations of 400,000
ducks, white-fronted geese and blue and snow geese. Many wading birds
nest in the pool including roseate spoon1bills, white-faced ibises, white
ibises, common and snowy egrets, Louisiana and little blue herons, black-
crowned and yellow-crowned night herons and anhingas. Here also is the
first American nestin g colony of cattle egrets outside of Florida. Vegeta-
tion consists primarily of bulltongue, maidencane, watershield, waterlily,
spikerush, and southern bulrush. The pool provides excellent largemouth
bass fishing.

3) Grand Ecaille Sulphur Pits. Freeport Sulphur Company has
created a unique situation in Southeastern Barataria Bay with the impound-
ment of two pits of 134 acres. These pits were created by leveeing off an
area of saline marsh and are utilized as a source of freshwater for the
nearby Sulphur mine. Freshwater is heated in boilers and then pumped
underground to melt sulphur deposits. The need for freshwater for the
mining process has lead to the impoundment of the reservoirs. Surrounded
by the saline waters of Lake Grand Ecaille, the pits support excellent
populations of largemouth bass.

4) Garden Island Bay Sulphur Pits. These pits were created for
the same purpose as those at Grand Ecaille by Freeport Sulphur Company.
They are located off Cadro Pass south of Pass a Loutre and consist of two
pits of approximately 650 acres with an average depth of 6 to 8 feet. The
periodic pumping of nutrient rich river water into the reservoir continually
rejuvenates and fertilizes its waters and produces a lush growth of sub-
mergent grasses. Small forage fish such as gizzard shad, skipjack herring,
and different species of shiners are also introduced into the pits when
pumping occurs. Due to the warm waters of the Gulf that surround the Delta
and the fact that the Delta extends for over 100 miles into the Gulf below
New Orleans, a nearly year round growing season occurs. Temperatures
are characteristic of a tropical to semi-tropical climatic regime and the
area annually has over @50 frost-free days. These conditions combine to
produce a phenomenal growth rate of the fishes present in the pits. Large
populations of large mouth bass, yellow bass, black crappie, bluegill, blue
catfish, striped mullet, and alligator gar occur which provide excellent
sport fishing. The pits are located within the Pass a loutre Public Shooting
Grounds and also provide good waterfowl hunting.

Environmental Management Units III, IV, VIII and IX.

Source of Information:
Burk and Associates, Inc. 1976. Field investigations
by staff personnel.

"loll-III

Deep freshwater marsh. Sabine Refuge pool

Bureau of Sport Fisheries and Wildlife. 1974. Proposed
Lacassine Wilderness Area, Louisiana. Draft
Environmental Statement.
Walther, John. Refuge Manager, Sabine Refuge.
Personal communication.

7. New Atchafalaya Delta
Deposition of alluvial sediments by the various sub deltas of
the Mississippi River is tho primary factor rosponsible for the crcatioii of
all of what is today's coastal Louisiana. * This basic geological process
has been greatly restricted due to man-made levees along the Mississippi's
channel. Today, the dominant geological process in the coastal area is
one of land loss due to subsidence, salt water intrusion and wave induced
erosion. The Mississippi's deltaic plain is in various stages of deteriora-
tion as the Gulf's tides and waves constantly eat away at the coastal
marshes. However, in Atchafalaya Bay, the Atchafalaya River is building
a new delta. The Atchafalaya is the Mississippi's major tributary and
carries a tremendous load of silt. Much of this silt is being deposited as
mud flats at the river's mouth and a new land mass is gradually taking form
in northern Atchafalaya Bay. Eventually, as natural levees and interior
marsh develop, the delta will take on the physical appearance of the active
delta at the mouth of the Mississippi. Fish and wildlife characteristic of
the Mississippi Delta will gradually become established. Ideal habitat for
waterfowl, fur-bearers, freshwater and estuarine fishes will develop. The
new delta will contain approximately 192,000 acres and will extend out
beyond Point au Fer Island by the year 2020.

Although this process of delta building was an inherent characteristic
of the past geological history of coastal Louisiana, it is unique today because
of man's activities. This new delta represents the major area on the coast
where accretion and land building is occurring.

Environmental Management Unit V.

Source of Information:
Gagliano, S.M. and J.L. van Beek. 1970. Geologic and
Geomorphic Aspects of Deltaic Processes, Mississippi
Delta System. Hydrologic and Geologic Studies of
Coastal Louisiana, Report No. 1, Coastal Resources
Unit, Center for Wetland Resources, LSU, Baton Rouge, La.
Duffy, McFadden. 1976. Of Time and the River. Louisiana
Conservationist, Vol. 28 (3 & 4).

8. Big Woods Island, Dewevville Terr'ace
Big Woods Island represents the westernmost meander scar of
the Mississippi River delta. Originally part of an active channel of the
Vermilion River, an old Mississippi distributary, this island is on the
dividing line between the deltaic and chenier plain marshes. Geologically,
it is known as a Deweyville Terrace and consists of a series of ridges and
swales that were produced by the gradual movement of the Vermilion River
channel. Thi-s shifting of the river deposited sediments along cut banks
which accumulated.into low arcuate ridges.

Big Woods Island and adjoining Palmetto Island have dense growths
of bottomland hardwoods and are surrounded by cypress swamp. The swamp
probably represents the old filled river channel. Both islands are about 4
square miles in size and elevated 5 to 6 feet above the surrounding swamp.
Palmetto Island has been proposed as a state preservation area in the state
.parks system. The islands are located near Esther, Louisiana.

Environmental Management Unit VIII.

Source of Information:
Burk and Associates, Inc., 1976. Field investigation
by staff personnel.
McIntire, William. Geologist, Coastal Studies Institute.
Personal communication,

MISCELLANEOUS
FEATURES

D. MISCELLANEOUS FEATURES

1. Potential Registered Natural Landmarks
Five of the areas listed as unique botanical communities have
been nominated as Potential Registered Natural Landmarks. The National
Registry of Natural Landmarks is a program administered by the National
Park Service with the objective of encouraging preservation of sites signi-
ficantly illustrating the geological and ecological character of the United
States. The landmarks are also chosen to enhance the educational, sci-
entific and cultural value of. the sites and to foster a greater concern for the
conservation of the nation's natural heritage.

The sites recommended as natural landmarks are the Pontchatoula
marsh in Tangipahoa Parish; Honey Island Swamp in St. Tammany Parish;
Blind River Swamp in Livingston, St. James and Ascension Parishes; Amite
and Tickfaw Rivers in Livingston Parish and the Atchafalaya Basin in St.
Martin, St. Mary and Assumption Parishes. The Atchafalaya Basin has also
been proposed as a preservation area.

Environmental Management Unit I, V and VI.

Source of Information:
Goodwin, Richard H. and William A. Niering. 197 1.
Inland Waterways of the United States Evaluated
as Potential Registered Natural Landmarks. Vol. I.
Alabama to Missouri. U.S.D.I. National Park
Service, Washington, D.C.

Numerous other sites that have been described in this report should
be evaluated as possible registered natural landmarks. Some of these areas
meet the criteria established for natural landmarks,yet have not been recom-
mended for this status. It is only through programs such as this that these
unique environments can be preserved and protected. All of the coastal fea-
tures discussed in this report should also be evaluated for possible designa-
tion as preservation areas as required by the Coastal Zone Management Act of
1972. Undoubtedly, certain ones will meet the criteria established for desig-
nation 'of such areas.

In the final analysis, it is the ecological, hydrological and geological
processes that produced these unique features that ultimately need preserving.
In a deltaic environment as dynamic as coastal Louisiana, many of the land-
forms are only temporary. They constantly change in response to dominant pro-
cesses such as erosion" accretion, tidal currents, storms and organic
production. If these processes are maintained, unique features that exist in
today's coastal Louisiana will always be a part of this valuable ecosystem.

I
I
I
I
I
I
I
I
C":
@,t
-It- I-, . . ,I , @"fii
@ @ @ ,,I @6
!:@ 1 , @j :@ '..
Ulf I- I
I
I
I
I
I
I
I
I
I
I

3 6668 14109 5283