Boat strikes killing more whales as more come to Long Island and region for food, experts say

Long Island and the region has seen a record number of dead whales wash ashore this year as part of a six-year long Unusual Mortality Event that experts say is largely due to boat strikes as more of the marine mammals come to local waters to feed.

Two humpback whales washed ashore on Long Island beaches in the past week, one Aug. 11 at Smith Point County Park and another that washed ashore Monday night at Long Beach. Both whales showed signs of blunt force trauma, consistent with boat strikes, following necropsies to examine a possible cause of death.

“Ship strikes are a major culprit. They’re playing in traffic unfortunately,” said Paul Sieswerda, director of Gotham Whale, a nonprofit whale tracking organization. “One may think they might be aware of the ship, but for some reason they’re not able to evade these vessels. Sometimes the size of these ship are immense, and ships may not be aware.”

There have been at least 16 whales found dead this year, marking a record year for deaths in the New York-New Jersey region, exceeding the 14 whales that died in 2017, mostly off Long Island. The deaths are part of a larger Unusual Mortality Event since 2016 tracked by biologists and conservationists along the East Coast.

Experts say there has also been a large increase in whales spotted off Long Island, feeding off the same schools of tiny menhaden fish that also lure sharks closer to shore. The humpback whales, dolphins and other marine life are coming closer to shore due to cleaner and warmer waters, experts said.

In many cases, officials say, whales are crossing shipping channels to get to the food, but are then placed at risk from other human activity such as recreational boating and becoming entangled in fishing nets.

There have been eight humpback whales that washed ashore on Long Island this year and three Minke whales, which died as part of a separate mortality event suspected to be from disease or biological causes, said Robert DiGiovanni, director of the Atlantic Marine Conservation Society, known as AMSEAS.

He said the number of deaths this year correlates with an increased number of offshore sightings of whales. He noted humpback whales are not endangered and said the trend in deaths may be linked to more whales coming to the region earlier in winter and spring, when they generally don’t arrive until the summer.

“They’re coming in an area closer to shore with more activity. We know they’re coming across the shipping lanes, and if there’s food in the shipping lanes," DiGiovanni said.

About half of the whales examined on regional beaches this year show signs of human interactions, either through boat strikes or fishing nets, DiGiovanni said, but some were too badly decomposed to determine an exact cause of death.

Some critics have said that the soundwaves produced by sonar used to map the ocean floor for constructing offshore wind turbines may also be harming the whales. But, to date, no deaths since the beginning of the current Northwest Atlantic humpback whale mortality event have been attributed to offshore wind activities, according to The National Oceanic and Atmospheric Administration Fisheries.

DiGiovanni, who urged the public to notify AMSEAS about whale sightings, said it’s unknown how the mortality event has affected the overall population of whales.

More whales are also being drawn to Long Island due to warmer waters as a result of climate change, said Regina Asmutis-Silvia, director of the Massachusetts Whale & Dolphin Conservation.

There have been more than 200 humpback whales found dead off the East coast since the mortality event began in 2016, she said. She said climate change has pushed humpback whales to Montauk waters that would usually be seen in the Gulf of Maine, north of Cape Cod at this time of year.

“From the conservation perspective, it’s a huge concern. This mortality event is along the entire East Coast, and it’s not just animals washing up in New York,” Asmutis-Silvia said. “We know the threats are up and down the Eastern Seaboard and it makes it more publicly aware of it. These are risks they are facing throughout the region.”

By John Asbury

john.asbury@newsday.comJohnAsbury

John Asbury is a breaking news and general assignment reporter. He has been with Newsday since 2014 and previously worked at The Press-Enterprise in Riverside, California.