The primary mission of the Great South Bay Audubon Society is to advocate for the conservation of habitats for native birds and other native wildlife on Long Island.

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GSBAS Chapter Articles

Are We Approaching the Tipping Point for Nitrogen Loading in the Great South Bay Estuary?

Maria Brown, MS, PWS - Great South Bay Audubon Conservation Chair

This past May, as I looked out to the Great South Bay Estuary from the salt marsh at the Long Island Maritime Museum, I was saddened by the reappearance of the brown color caused by the harmful and nuisance algal bloom known as “Brown Tide” (Aureococcus anophagefferens). This bloom peaked in the cool temperatures of our coastal waters on the south shore of Long Island until mid-July. Although it may appear as an unsightly landscape to humans, the impacts of Brown Tide go far deeper with the potential for permanently degrading our marine environment and reducing the landings for both shellfish and finfish. With its first appearance in 1985 in the Peconics, Brown Tide devastated the Peconic bay scallop (Agropecten irradians) industry and crippled its nursery habitat comprised of eelgrass (Zostera marina) resulting in significantly reduced scallop landings and adversely impacted Long Island’s maritime economy. This is the third consecutive year that Brown Tide has bloomed in the Great South Bay Estuary to levels that present a risk for both adult and juvenile shellfish (Dooley, 2015).

In 1982, the harvest of 500,000 pounds of bay scallops from the Peconic Estuary accounted for 28% of all U.S. commercial landings and had a dockside value of 1.8 million dollars (Seagrass.LI, 2012). Landings hovered between 2,000 and 4,000 pounds for two decades, reaching a maximum of 18,000 pounds harvested in 2009 in the Peconics , and there has been a continued decline in landings for Great South Bay since 2006 as well (Peconic Baykeeper, 2011). In response to the scallop decline, an already stressed hard clam population in Great South Bay became the focus for harvesting. In 2008, Senator Chuck Schumer declared the hard clam industry a “fishery disaster” where in that year only $600 thousand was landed compared to $12 million at the fishery’s peak.

How then, does nitrogen play a role in this cacophony which degrades the ecosystem services of our once bountiful estuary, and what should be done to protect our ability to harvest food from our surrounding coastal waters now and in the future?

A natural nutrient in aquatic ecosystems, nitrogen and phosphorous in excess levels can promote harmful algal blooms which ultimately consume oxygen , normally available to other aquatic organisms; block sunlight, compromising the ability of marine plants to photosynthesize; and in some cases produce toxins such as red tide (Cochlodinium polykrikoides) which is the primary agent that causes paralytic shellfish poisoning. In 2010, the New York State Department of Environmental Conservation (DEC) declared the South Shore Estuary as “Impaired Waters” and cited the causes to be Brown Tide and nitrogen loading released into surface and ground waters. Nitrogen is deposited into the Great South Bay ecosystems via direct atmospheric deposition (30%), fertilizer application (15%), and wastewater (55%) (Kinney & Valiela, 2011). Between 1987 and 2005, nitrogen levels in the upper layer of our sole source aquifer (Glacial aquifer) rose 40%, while levels in the middle aquifer (Magothy) rose 200% (Peconic Baykeeper, 2012). These rates of nitrogen inflow could potentially exceed the drinking water standards of 10 mg/L by 2050. In coastal waters, the acceptable level of total nitrogen is less than 0.45 mg/L and when exceeded, leads to harmful algal blooms, increased plant growth, decreased dissolved oxygen, lower water clarity, loss of eelgrass, fish kills, and dramatic changes to the phytoplankton and zooplankton communities (Baykeeper, 2012).

So what is the pathway of the source of nitrogen to our surface and groundwater?

Sewage for Long Island is either piped to a sewage treatment plant, or piped to an underground septic system or a cesspool, otherwise known as onsite wastewater disposal systems (OWDS). In Suffolk County, wastewater for 80% of residences is handled via an OWDS. During pump-outs, these systems only remove a small fraction of nitrogen leaving a large portion of the nitrogen to pass to the cesspool and ultimately into the soil and groundwater which feeds our surface waters (ponds, creeks, lakes, streams, and bays).

Fertilizer also contributes to the nitrogen loading in our waterways. Each spring, many Long Islander’s apply nitrogen-rich fertilizer which when not taken up by plants, flows directly into surface waters as non-point source runoff or leaches through the soil into the ground water. Suffolk County enacted Local Law No. 41 in 2007 with the goal to reduce nitrogen pollution by reducing use of fertilizer in Suffolk County. This Law prohibits lawn fertilizer applications from November 1- April 1 (non-growing season). Additionally, it is prohibited to apply fertilizer within 20 feet of a water body or a wetland. For those who do not comply, they run the risk of receiving a $1000.00 fine for both residential homeowners and landscapers. To learn more about the law visit

Unfortunately this year, Law 41-2007 may not have reached its goal, failing to protect our local waterways including the Great South Bay. The harsh winter lead to a delayed growing season on Long Island with some species delayed in the range of 2-4 weeks as reported by Long Island’s local farmers. As most people are on an “annual cycle” for maintaining their lawns and applying fertilizer, the April fertilizer application applied by Long Islander’s may not have been taken up by plants if they had not begun to grow yet. To complicate matters, we also experienced a mini-drought period followed by heavy rains which may have provided a dangerous pathway for excess nitrogen to reach our surface and ground waters. According to Samantha Borisoff, climatologist with the Northeast Regional Climate Center based at Cornell University, April 1-May 20th were the driest years on record for MacArthur Airport since it began keeping records in 1984.
Long Island oyster farmer Chris Quartuccio and owner of Blue Island Oyster Farms, in West Sayville indicated that last year he had 50% die off of his oysters which are held at his Captree Farm before distribution around the country which he attributes to Brown Tide. Oyster Hatchery owner, Billy Hart, also located in West Sayville, observed a total spawning “shut down” of adult oysters and “no growth” periods this summer during the Brown Tide events. “As soon as the waters warmed above 76 degrees Fahrenheit, the Brown Tide dissipated and the oysters resumed spawning and growth spurts” declared Billy, “but the impacts economically will not be known until the end of the spawning and growing season.” Oysters and clams are filter feeders and are extremely important in the overall health of the bay systems around Long Island (Gobler, 2015), and keeping the water clarity high improves the overall quality of the bay for all of the organisms to thrive. Direct Impacts to avian populations from excess nitrogen loading and algae blooms is still poorly understood, but if organisms are experiencing stress at lower feeding levels in the food chain (trophic levels), it may well have adverse impacts to bird populations that commonly interface with the near-shore environment.

In hopes of securing an estuary that will continue to produce food, Chris Quartuccio initiated a Project called “Operation Blue Earth”. By distributing car magnets and lawn ornaments with a green circle (land) surrounded by a blue circle (ocean), the project is designed to spark a conversation between residents of Long Island to discuss the impacts of nitrogen loading on oyster and clam production in our local waters with the ultimate goal of better educating the Long Island community about nitrogen impacts to our aquatic ecosystems, maritime economics, and the potential losses of food resources. Blue Island Oyster Company is funding this campaign and is working closely with Sayville High School’s Environmental Club (SWEEP) President, Jack Novak to spread the word and sponsor community outreach events to better educate residents on chemical free lawn care options. To learn more about Operation Blue Earth Friend them on FaceBook!

As there is a tremendous amount of research still necessary to better understand the mechanism that take place between human-induced nitrogen loading on ecosystem health, there are still many actions that individuals can do to reduce their nitrogen footprint. Here are some tips for helping to reduce nitrogen to our wonderful Long Island resources:

As Marine Scientist, Kevin McAllister told 1010 WINS’ reporter Mona Rivera (June, 2010) “We’ve reached our tipping point in our bays relative to nitrogen pollution.” Kevin works for the group Defend H2O.

We all need to do our part and each person can make a difference in protecting our water resources for future generations.