New data show New York's coastal waters are facing a worsening mix of toxic blooms, dead zones and conditions that could favor Vibrio vulnificus, a bacterium that can cause severe infections. Professor Christopher Gobler delivered that warning this week at Peconic Riverfront Park in Riverhead, saying there is no time to waste.
Gobler said dozens and dozens of locations in estuaries, harbors, bays and ponds across Long Island are failing state and federal water-quality standards, and that harmful algal blooms are producing toxins that can sicken or even kill animals and people. He pointed to dogs on Long Island that have gotten sick and died after drinking lake water, and said last year more than two dozen lakes and ponds had blue-green algal blooms while five different locations were closed to shellfishing because of toxins.
In Southold Town, he said levels of alexandrium rose so high they could have caused extreme sickness and possibly death, prompting the New York State Department of Environmental Conservation to close the site to shellfishing before anyone got sick. Gobler said 2026 is not off to a great start, with three different systems already closed to shellfishing in Southold and the entire half of Shinnecock Bay also shut to shellfishing.
The broader problem, he said, is nitrogen pouring from land to sea, largely from onsite septic systems, with climate change adding pressure. He described the current outbreak as the most intense paralytic shellfish poisoning harmful algal bloom in the history of New York and said low-oxygen dead zones are also expanding, harming marine life. That same pollution mix, he said, now has new evidence of creating environmental conditions that promote Vibrio vulnificus in Long Island waters.
The Centers for Disease Control and Prevention says Vibrio bacteria naturally live in some coastal waters and are more common from May through October, when water temperatures are warmer. It says some species, including Vibrio vulnificus, can cause severe, life-threatening infections, and in some cases necrotizing fasciitis, in which flesh around an open wound dies. Gobler said the crisis is serious now, but that the science also points to a clear fix: cut nitrogen, curb septic pollution and act before the summer water temperatures make the risk worse.