There are nearly 1,000 bottlenose dolphins that have died and have been washed ashore from the seaboards of New York to Florida due to morbillivirus, according to The New York Times.

Marine scientists are alarmed by the number of deaths, which according to them, is eight times the historical average of deaths among the sea mammals, the report said.

The morbillivirus killed 700 dolphins 25 years ago left marine scientists baffled. Scientists say it remains unclear why dolphins have succumbed to the disease.

"Marine mammals are very good sentinels for ocean and human health, and they really act like the proverbial canaries in a coal mine," Dr. Greg Bossart, a veterinary pathologist and senior vice president in charge of animal health at the Georgia Aquarium, told the Times. "They give us an idea of what's occurring in the environment."

According to Bossart, they find the deaths worrying because bottlenose dolphins are top predators with longer life spans.

"Whatever happens coastally impacts them and potentially us," Bossart added.

Scientists have classified the deaths as an unusual mortality event because they can't find any discernible demographic pattern. The deaths have affected young and old dolphins, both male and female. According to the scientists, one possible explanation is that the dead dolphins may not have been around during the first outbreak 25 years ago and were not immune to the virus.

Scientists are now questioning the health of the ocean and what role environmental factors have played in the dolphin deaths along Florida's east and west coasts.

The worse-off area was in Florida where nearly 80 dolphins that live in the Indian River Lagoon perished, while another 233 dolphins died this year in the Gulf of Mexico, the Times said.

The current dolphin mortality has alarmed scientists because causes of death remain unrelated.

"It is alarming when you see so many different die-offs of marine mammals going on at once," Erin Fougeres, a marine mammal biologist with the National Oceanic and Atmospheric Administration's fisheries service, whose been investigating the dolphins' unusual deaths, told the Times. "We can't say they are linked. But it says there are a lot of challenges that marine mammals are facing."