This past summer, excessive nitrogen affected water quality across Long Island — and Shelter Island was no exception.
Last month, the Long Island Clean Water Partnership reported that from May through August, every major bay and estuary across the Long Island fell victim to toxic algae bloom or reduced oxygen or both.
A map released by the partnership shows four creeks in Mattituck, all within about two miles of each other, that have been affected by alexandrium, which led to the detection of paralytic shellfish poisoning, or PSP, this summer. The impacted waters were James Creek, Mattituck Creek, Deep Hole Creek and Halls Creek.
What wasn’t shown was Shelter Island’s Fresh Pond, which suffered an algae bloom this summer.
In addition, Peconic Bay experienced rust tide, while areas close to the mouth of the Peconic River were found to suffer from oxygen depletion, or hypoxia. In Mattituck, Marratooka Lake continued to experience blue-green algae, which has been confirmed there in years past.
“Something’s going on here,” said Dr. Chris Gobler of Stony Brook University’s School of Atmospheric and Marine Science, whose labs monitored Long Island waters over the summer. “We could all point fingers and speculate, but it’s certainly an area of concern.”
According to a 2014 study by The Nature Conservancy, agriculture, as well as septic and cesspool systems, are the largest sources of the nitrogen that infiltrates the region’s water systems.
“To improve the condition in some of these tributaries action will need to be taken,” Dr. Gobler said. “The biggest thing is addressing the nutrients that are coming in from land to these coastal waters. Part of it’s going to be reducing the use of fertilizer and upgrading septic systems.”
In September, Suffolk County released a “Harmful Algae Bloom” action plan, which acknowledges how such blooms have disrupted coastal food webs, such as that of shellfish that act as natural water filters. The HAB study warns of ecological, public health and economic impacts if steps are not taken to address water quality issues.
In 2016, East End voters approved a referendum to extend the Peconic Bay Community Preservation Fund to allow up to 20 percent of new proceeds to be used toward improving water quality.
Last week, the U.S. Senate passed the Harmful Algal Bloom and Hypoxia Research Control Amendment Act of 2017, which was co-sponsored by Senator Chuck Schumer (D-NY).
The legislation seeks to earmark $22 million for each fiscal year 2019 through 2023 toward reducing the impact of algae blooms and hypoxia in affected waters nationwide. It must next be considered by the House of Representatives.
In a letter urging Congress to secure the funding, County Executive Steve Bellone said Long Island is facing a “water quality crisis.”
The county has been pushing residents to replace their old septic systems and cesspools with advanced treatment systems that reduce nitrogen output. Since it was launched in July, more than 600 Suffolk residents have registered for a septic improvement program that provides financial incentives through grants and low-interest financing for replacement of outdated systems, the county reported last month.