mud which is discharged along with drill cuttings. The mud is mostly composed 

 of fine clays which readily form long-lasting turbid suspensions. If the pro- 

 jected maximum of offshore production platforms (50 for the Mid Atlantic) is 

 realized, then the combined operations could possibly cause a diminution in 

 regional planktonic populations. The locations of the production platforms 

 cannot yet be determined, but it is estimated that one platform will be re- 

 quired for e^ery four lease blocks (over 20,000 acres)(13,p.23). 



Phytoplankton communities form the base of the marine food chain in 

 that they are able to photosynthesize, fix carbon, and produce complex mole- 

 cules. Such organisms--algae and diatoms--are eaten either by the zooplankton 

 or by planktonivorous fish such as shad. Indications are that, for the Atlan- 

 tic 0CS region, planktonic species are generally evenly distributed although 

 the population biomasses may exhibit extreme "patchiness" (l,p.H6). 



Phytoplankton are found in the euphotic zone, which may extend to the 

 200 foot depth off the Atlantic Coast. Thus a spill or extensive amount 

 of turbidity may have no effect one month but cause massive problems 

 at a different time, depending on the concentration of plankton. 



Of major consideration in the plankton are pelagic larvae of fish and 



shellfish. The distribution and concentration of the ichthyoplankton varies 



with the seasons. Such planktonic larvae may suffer mortalities on a seasonal 



basis by events such as an oil spill. 



Other commercially important species that may be impacted include 

 the planktonic larvae of the surf clam, soft-shelled crab, sea 

 scallop, American lobster, lue crab, rock crab, Jonah crab, 

 ocean quahog, southern quahog, northern quahog, and American 

 oyster (1 ,p.H6). 



Marine mammals may be affected by 0CS development in the Atlantic, 



but probably only to a very slight degree. There are no known concentrations 



54 



