Stage 1 



Stage 2 



ECOLOGY OF BUZZARDS BAY: An Estuarine Profile 



Stage 3 



45 



- o 



k3 



Fiber blanket 



Water 



^finfPniraqiM 



Fig. 4.2. Alterations in benthic communities and relation to sediment oxidation/reduction state under varying 

 levels of (a) physical disturbance, or (b) nutrient and organic matter pollution. From Rhoads and Germano 

 (1982). 



sediments, whereas areas of finer grained, silty sedi- 

 ments are dominated by the nematode 

 Terschellingia spp. and kinorhynchs such as 

 Trachydemus spp. Observations of the distribu- 

 tion of these dominant metazoans are comparable 

 to Sanders' ( 1 958, 1 960) sand and silt distinctions 

 for macro fauna, with combinations of spe- 

 cies determined by the relative amounts of sand 

 versus fine deposits present. 



Shellfish. Shellfish are benthic animals and in 

 most cases infauna; however, because they sup- 

 port commercial and recreational fisheries, they have 

 special conditions regulating their population densi- 

 ties. Shellfish are relatively fast growing and easy to 

 harvest. Buzzards Bay, with its many protected 

 harbors and embayments, provides numerous 



suitable habitats for hard-and soft-shelled clams, 

 oysters, and scallops. Shellfish are also important 

 in coastal food chains with large numbers of eggs 

 and larvae entering the plankton during spring and 

 summer months providing a food source for juve- 

 nile fish and crustaceans. Suitable habitat is impor- 

 tant to the production of shellfish in that the young 

 of various species require specific types of substrates 

 or sediment grain sizes upon which to settle or bur- 

 row. Various shellfish species have specific salinity 

 and temperature ranges for reproduction and 

 growth. Water circulation also plays a role in main- 

 taining temperature and oxygen conditions as well 

 as in transporting planktonic food, since all of the 

 harvested bivalve species are filter feeders. Hard- 

 shell clams or quahogs, soft-shell clams, scallops, 



