A Summer of Discontent in Long Island’s Coastal Waters

As the leaves fall off the trees across Long Island, summer may seem like a distant memory. But local scientists have completed their assessment of water quality in Long Island’s estuaries during the summer of 2013 and the news is not good. During the months of May through September, every major bay and estuary across Long Island was afflicted by a toxic algae bloom or oxygen starved waters or both. Heavy loads of nitrogen from sewage and fertilizers have been cited as the ultimate culprits beyond these disturbing events.

“It began with toxic red tides in May and ended with a harmful brown tide that continues today across the entire south shore of Long Island,” said Dr. Christopher Gobler, Professor of Stony Brook University. “In between, we witnessed toxic blue green algae in five lakes across the Island, the largest ever Rust Tide on the east end, seaweeds on ocean beaches, a rash of oxygen depleted waters from Manhattan to Mattituck, and more. While we have seen these events individually in the past, the confluence of all of these events in a single season is a troubling development.”

And all of these events can be traced back to the rising levels of nitrogen coming from land and entering Long Island’s surface waters. The largest sources of nitrogen are household sewage and fertilizers which in many parts of Long Island, are washed into groundwater that seeps in bays, harbors, and estuaries. This nitrogen stimulates toxic algal blooms that can, in turn, remove oxygen from bottom waters as they decay.

“Long Islander’s should take this as a call to arms,” said Adrienne Esposito, Executive Director of Citizen’s Campaign for the Environment. “Our bays are dying and the science clearly shows us why. Now is the time for lawmakers to pass legislation that creates a governing body to protect our bays and creates standards to lower nitrogen entering our coastal waters.”

Beyond their unsightliness, the occurrence of these events such as brown tide, have led to the collapse of critical marine habitats such as seagrass and major fisheries on Long Island such as scallops and clams. Groups such as The Nature Conservancy have been making efforts for more than a decade to revive and restore these habitats and shellfish, but have been challenged by the events such as those witnessed during the summer of 2013.

“While we had hoped we could simply plant seagrass and clams to bring back our bays,” said Carl LoBue, Senior Scientist for the Nature Conservancy, “2013 has taught us that these efforts will only be successful if we can get nitrogen loads under control.”

The report on the summer of 2013 was compiled by The Nature Conservancy in collaboration with Dr. Christopher Gobler, Professor of Stony Brook University, whose lab groups has been monitoring and sampling Long Island’s waters on a weekly basis all year. Data was also collected from the NYSDEC and the Long Island Sound Study which is funded by USEPA.

The map generated by the report shows precisely where on Long Island various algal blooms and low oxygen zones developed during the summer of 2013. Events depicted include algal blooms caused by Alexandrium and Dinophysis causing paralytic and diarrhetic shellfish poisoning, respectively, rust tides caused by the algae Cochlodinium, brown tides caused by Aureococcus, toxic blue green algae blooms commonly caused by Microcystis, and seaweed blooms caused by Ulva. The map also depicts hypoxic or low oxygen zones which are dangerous to marine life in Long Island Sound, Smithown Bay, Hewlitt Bay, the Forge River, and Mattituck Creek.