COLONIAL NESTING BIRDS 
80 
22 SPECIES 
NESTING 
PR IRS 
C1000s) 
YERR 
Figure 2.2. Abundance of colonial nesting birds during 1973-1987 (33,35). 
nCTIVE 
COLONIES 
alligator (Alligator mississippiensis) has recently become a harvestable animal under state statutes 
(39). During 1984-1986, a total of 655 alligators were harvested from the counties surrounding the 
estuary, with 384 (59 percent) taken in freshwater marshes of Chambers County. 
Reptiles that frequent the system and have been identified as threatened or endangered by the 
U.S. Fish and Wildlife Service (33) include: Dermochelys coriacea (leatherback sea turtle), Lepido- 
chelys kempi (Kemp's ridley sea turtle), Caretta caretta (loggerhead sea turtle) and Chelonia mydas 
(green sea turtle). Sea turtles were once an important component of the bay system, so much so that 
there was a commercial sea turtle fishery in Galveston Bay during the 1890's (40). 
Mammals—Schmidly (41, 42) documents 54 species of mammals for the counties surrounding 
Galveston Bay. Of these, 15 are furbearers and one is a game species (Table 2.10). The mammals most 
dependent upon wetlands environments include Sylvilagus aquaticus (swamp rabbit), Sciurus 
carolinensis (gray squirrel). Castor canadensis (beaver). Ondatra zibethicus (muskrat), Rattus 
rattus (roof rat), Oryzomys palustris (northern rice rat), Myocastor coypus (nutria), Procyon lotor 
(raccoon), Mustela vison (mink), Lutra canadensis (river otter), and Tursiops truncatus (bot¬ 
tlenosed dolphin). 
Dynamics and Interactions 
Some of the relationships of organisms to their physical environments were considered previ¬ 
ously, but the interactions of groups of organisms with extrinsic factors such as temperature, salinity, 
substrate and habitat availability need to be emphasized. This section will generally follow the 
trophic structure of the estuary. 
Primary Productivity 
The relative contribution of each floral component to total system primary production has been 
37 
