300 



Moriches Bay and Great South Bay., L.I. 



Information for this case study was supplied by contract investiga- 

 tions conducted as part of the National Estuarine Pollution Study, 

 two Federal enforcement conference proceedings and a report of the 

 Nassau-Suffolk Kegional Planning Board (IV-6-5) . 



Up to 7 million ducks annually live in farms located on Moriches 

 Bay and parts of Great South Bay. These ducks are a source of pollu- 

 tion to the bays. In one form, they cause the closing of valuable shell- 

 fish beds due to high coliform counts. Another form of pollution they 

 create is BOD and eutrophication due to the duck sludge which covers 

 the bottom of the bay in some sections. 



Studies conducted by the Division of Laboratories and Research of 

 the New York State Department of Health on duck wastes have shown 

 them to be high in solids, BOD, nutrients, bacterial content, and con- 

 stitute a public health hazard. It was found that the strength and 

 volume of the wastes reaching the waste stream depended on the num- 

 ber, age, activity, position of ducks in the pens, amount of rainfall, 

 runoff area, normal water use at the farms, and availability of water 

 to the ducks. 



Coliform densities were found to vary from a median MPN of 

 5.8X10'' per 100 ml. to 60X10« per 100 ml. Typical water usages 

 ranged from 0.290 mgd to 3.0 mgd per farm and from 14 gallon to 120 

 gallons per day per duck. 



Since 1940, there has been a decline in the oyster and fish production 

 of Great South Bay. These conditions have coincided with the buildup 

 of the duck industry in the areas surrounding Moriches Bay. The 

 wastes from the duck farms effectively fertilized these waters but with 

 a low ratio of nitrogen to phosphorus. 



As a result of the increased nutrients, especially phosphorus, the 

 waters of Great South Bay have exhibited increased algal populations. 

 Heavy growths of algae developed in the early spring and persisted 

 through summer and fall. At its peak, the conce^ntration of algal cells 

 exceeded 10 million/ml. The dominant bloom algae was a small, uni- 

 cellular species often termed "small form." This algae differed greatly 

 from the flora typical of bays and estuaries in the same region and its 

 persistance over long periods of time eliminated the typical seasonal 

 succession of forms in the bay. 



The decline of the oyster industry was directly correlated with the 

 increase in the "small form." This was due to the fact that the optimum 

 conditions for oytser growth included a mixed algal population. Al- 

 though oysters do feed on the "small forms," these algae are an in- 

 adequate nutrient source. Serpulid worms which are capable of 

 effectively utilizing the "small forms" for food have overrun the oyster 

 beds periodically and thereby adversely affected oyster production by 

 competitive exclusion. 



The report of the Nassau-Suffolk Regional Planning Board, "The 

 Status and Potential of the Marine Environment," states that "the 

 oyster industry has declined 99 percent in the past 50 years from $50 

 million to $1/2 million" ( p. 2-7) . 



In addition to the habitat damage caused by the duck farm wastes, 

 there are productive areas of shellfish beds closed because of bacterial 

 contamination. 



