Heavy Rain Will Close Beaches This Week, Check Where On New App

After the remnants of Hurricane Ida dump what could be several inches of rain on Long Island Wednesday night, several popular swimming beaches are likely to be closed by state health officials because of high levels of bacteria that will be flushed into surface waters by runoff.

The same will go for popular clamming areas, because shellfish can filter bacteria from the water when they feed and become dangerous to eat for up to three or four days after a heavy rain.

Long Islanders who want to easily track where it is safe to swim or gather shellfish over the Labor Day weekend can tap into a new mobile phone app developed by marine scientists at Stony Brook University that carries up to the minute information about water quality across Long Island, closures of beaches or shellfishing areas and other water quality concerns.

When the sun breaks again and the breach towels and clam rakes come out for the final weekend of summer, the Stony Brook app can guide fun seekers to which ares are safe to swim or harvest from and show them exactly what the problems are at the locations that are closed.

“It’s an idea we had been thinking about for a while,” said Dr. Christopher Gobler, director of the Stony Brook Laboratory that conducts weekly water quality sampling for the state Department of Environmental Conservation. “We thought it would be good if we could get people information about water quality in their area in real time and make [geographic information systems] maps that make it easy to see what beaches are closed.”

Dr. Gobler’s scientists gather water quality data from 30 sites between Queens and Montauk every week and share their findings with the DEC and county health departments. After heavy rainfalls, several Long Island beaches routinely see spikes in levels of bacterias — including fecal coliform bacteria from human and animal waste — because of leaking residential septic systems or storm runoff streaming across areas where pets or wild animals frequently relieve themselves.

The health concerns from such spikes in bacteria typically only linger for a day or so and the DEC uses localized rainfall measurements to determine which beaches or shellfishing beds must be closed, so the threats are not universal and the Stony Brook app can help guide Long Islanders to places that it says are safe to go.

Each site will be displayed on a map and selecting a site will open a menu of data sets on exactly what was found in the water, from bacteria to nutrients to harmful algae blooms to oxygen levels — the last of which Dr. Gobler noted could even be used by fishermen to identify places were fish are unlikely to be lingering because of low oxygen.

The app will be in app stores next year, but for now can be downloaded at somas.stonybrook.edu/longislandbeaches for both Apple and Android phones.