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Claus, G. 1971. 



Life and pollution in Great South Bay. Underwater Nat. 7(1): 11-16. 



Per acre fertilizer usage on Long Island, N.Y. is about 50 times national 

 average. Most phosphates in these fertilizers are carried into bays and 

 coastal waters. Unnecessarily large amounts of highly toxic weed killers 

 and pesticides also are used, and these also are carried into the Bay. One 

 result of increased pollution has been decline of the shellfish industry in 

 New York. The famous Bluepoint oyster began to be affected in the early 

 1940s, and concerned communities enlisted help of scientists from the Woods 

 Hole Oceanographic Institution. Scientists discovered that in warm weather 

 the water turned a murky green from blooms of a unicellular green alga 

 termed "small form". Mass mortalities of shellfish coincided with blooms. 

 The organism was identified as Nannoohloris atomus, which frequently 

 exceeded a million cells per ml of water. It was concluded that shellfish 



mortality had three causes: 1) blooms suppressed growth of bivalves and 

 their normal food organisms, often leading to starvation; 2) being very 

 small, algae clogged ciliary tracts of bivalves, also interfering with 

 feeding; and 3) the alga had direct toxic effects on shellfishes. High 

 phosphate values were found in Bay waters. The source was identified as 

 the extensive duck farms on the eastern part of Long Island. Wastes from 

 duck farms were carried by streams into Moriches Bay and thence to Great 

 South Bay. A hurricane in 1934 closed Moriches Inlet, the only opening 

 from Moriches Bay to the sea. This .increased the flow of phosphate-loaded 

 wastes into Great South Bay. Flushing rate of the Great South Bay system 

 was estimated to be 48 days, allowing plenty of time for blooms to develop 

 in warm weather. Bacteriological studies showed that the common fecal 

 organism E. aoli was present in large numbers in Bay waters. Its presence 

 was attributed to duck farm effluents. Shellfishes from many beds in the 

 Bay also had high numbers of coliform bacteria, and this led to closure of 

 many shellfish beds. Duck farm operators now are required to treat their 

 effluents. Moriches Inlet was reopened, and the channel in the Bay was 

 dredged to decrease flushing time. Problems also exist with growing numbers 

 of pleasure boats using the Bay. More recent studies in the late 1960s 

 showed that flushing time was much less than calculated earlier, about 12 

 days. Duck farm wastes do not have high coliform counts when they enter 

 Moriches Bay. Smallest numbers of coliform organisms were often found in 

 streams and canals along the north shore of Great South Bay and highest 

 numbers near Fire Island Inlet. It was concluded that the counterclockwise 

 circulation carried water from the north shore toward the Inlet and that 

 coliform organisms multiplied during transit, originating from cesspools 

 and untreated sewage on the north shore. At the time of writing it was 

 concluded that harmful effects of domestic and industrial sewage were not 

 at levels dangerous to biota, and indeed could be improving the food supply 

 for bivalves. The bottom of Moriches Bay and streams carrying duck farm 

 wastes was covered with large numbers of hard clams. In 19 67 the Town of 

 Riverhead transplanted 1,800 bu of clams to clean waters, intending to 

 reharvest when clams had cleansed themselves. But clam diggers got to the 

 supply first, and in face of this economic loss the Town terminated the 

 program. Clams transplanted as an experiment into the polluted East River 

 did not die, as expected, but grew over a period of several months. 

 Sediments in Great South Bay contain high amounts of organic materials. 

 In summer this sometimes leads to oxygen depletion and production of H2S, 

 methane, and other toxins. Eelgrass and algae produce oxygen, which counters 

 these threats to bivalves, but the system is in delicate balance, and could 

 be jeopardized by disappearance of eelgrass or other environmental 

 variations, natural or man-made. Solutions proposed are a combined 

 sewer system that can handle land runoff as well as sewage, mandatory 

 waste holding and treatment facilities for all vessels, and elimination 

 of cesspools. The author was pessimistic that this will come about. 

 Great South Bay will turn into an anaerobic bog within 100 yrs if present 

 sedimentation rates continue. Even if recommended measures are carried 

 out, the Bay will come to the same end in about 300 yrs. This raises 

 questions about the economic benefits of spending the $1 billion estimated 

 as necessary to provide relief. - J.L.M. 



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