A Map of Algae Levels in The Great South Bay

The Breach Report July 8th, 2013 – Damaging Brown Tide Spreads Across Great South Bay, Cell Count Much Lower Near New Inlet – A Report From SCERP

With all the heavy rains in June, a lot of our ground water, heavily polluted by septic tanks and sewage, has washed into The Great South Bay, sparking the brown tide. The New Inlet is thus far keeping the brown tide out of the Eastern Great South Bay and Moriches Inlet. As The Long Island Clean Water Coalition contends, restoring our waters and safeguarding our drinking water depends on our ability to tackle the enormous problem of seepage from septic tanks / sewage. If we do not, our bays, rivers and ponds will be unswimmable and unfishable, and our water unfit to drink, cook, or bathe in.

The Stony Brook Southampton Coastal and Estuarine Research Program (SCERP) has just released its latest report on brown tide, this time in The Great South Bay.

Here is SCERP’s Press Release in full:

A Map of Algae Levels in The Great South Bay
Courtesy SCERP and Prof. Chris Gobler

June rains kick starts event; Presence of The New Inlet keeps levels lower in Eastern Bay

Stony Brook, NY, July 8th 2013 – An intense and damaging brown tide has emerged across much of Great South Bay. Monitoring by The Gobler Laboratory of Stony Brook University has revealed that a brown tide developed in late June in western Great South Bay and has intensified and spread east since. Abundances of the brown tide organism were recorded at more than 1,000,000 cells per milliliter in western Great South Bay as of July 2nd in the region between the Robert Moses Bridge and Islip. Densities declined to less than 100,000 cells per milliliter within eastern Great South Bay. Densities above 100,000 cells per milliliter can be harmful to marine life. This marks the first summer brown tide in Great South Bay since 2008.

The brown tide alga, Aureococcus anophagefferens, has been notorious on Long Island since it first appeared in 1985 having been responsible for the demise of the largest bay scallop fishery on the US east coast in the Peconic Estuary, the loss of eelgrass across Long Island, and the inhibition of hard clam recovery efforts in Great South Bay. While Great South Bay had been cleaner and clear of brown tide through early June, eight inches of rain (the equivalent of two months worth) fell during the second week of June, stimulating algal blooms and, ultimately, the brown tide. The only region of Great South Bay that has been spared high levels of brown tide is the eastern region of the Bay where a new ocean inlet formed following Hurricane Sandy.

“There are two important lessons this brown tide teaches us about Great South Bay,”, said Christopher Gobler, Professor of Marine and Atmospheric Sciences at Stony Brook University, “Firstly, extraordinarily heavy summer rains that deliver of excessive nitrogen derived from sewage and septic tanks can have a series of serious negative impacts on the Bay, including harmful brown tides. Second, the extra flushing provided by the new ocean inlet formed by Hurricane Sandy is sparing the eastern regions of Great South Bay and western Moriches Bay from the worst of this event. But clearly, this flushing is not enough to counteract the heavy loading of nitrogen from land.”

Gobler noted that since the new inlet was created, there has been higher salinity, lower nitrogen, stronger flushing, and less algae in eastern Great South Bay. He further noted that the inability of the brown tide organism to form an extremely dense bloom in this region is consistent with these conditions and that the inlet has been promoting the more rapid growth of hard clams in this region. Finally, he pointed out that the inlet is constantly evolving and flushing the Bay less now than it had in the spring.

Here are two sets of charts that show how cell count fluctuated with rain amounts throughout June, and how, with the ground saturated, the salinity levels have yet to return to previous levels.

Salinity Levels, GSB June 6- July, Courtesy SCERP
Temperature and Salinity Levels, GSB June 6- July, Courtesy SCERP
Rain Fall June 5th through July 8th GSB, Courtesy SCERP
Cell Count and Turbidity From Rain, June 5th through July 8th GSB, Courtesy SCERP

Finally, to Prof. Gobler’s point that the cleaner water around The New Inlet was having an effect on the growth ring size of clams near The New Inlet,  STGSB was sent the image below and the accompanying text:

Bellport Bay Clams -- Check Out The Growth Rings!
Bellport Bay Clams — Check Out The Growth Rings!

With this, we have an image of what The Great South Bay could be again.   The New Inlet is not only staving off the brown tide that is otherwise widespread across the bay, it is also revitalizing the waters around it.

These clams were harvested July 2nd 1.5 miles from The New Inlet by Greg Greene,  whose graduate thesis on  clams has been an important resource for those seeking to return them to The  Great South Bay.   Greg, who lives on the water near Bluepoint says

“Bellport  clams were always slow growing and larger ones stunted. I never saw clams with such distinguishable growth in that portion of the bay even when clams were more abundant. Their meats were very plump and fine tasting.”

Were it not for The New Inlet, the brown tide would most certainly have spread further east.   Were it not for The New Inlet, we wouldn’t really understand what a healthy bay would mean.

Brown tide press release July 2013





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