Why are Dead Bottlenose Dolphins Washing Up on the US East Coast?

Written by Derek Markham

Since the beginning of July, at least 124 bottlenose dolphins have washed ashore on the east coast of the US, all of them either dead or dying, and wildlife officials say that a fast-spreading infection could be behind the deaths.

While there is no definitive answer to the spike in mortality (up to seven times what is considered average), at least one of the dolphins did test positive for morbillivirus, which is often fatal to dolphins.

The National Marine Fisheries Service is declaring the fatalities to be an “unusual mortality event,” and are investigating the potential cause of death, which could also include biotoxins from harmful algae blooms, pollution, ship collisions or possible acoustic trauma from ships or other ocean infrastructure.

In 1987-88, bottlenose dolphins on the east coast were hit by a morbillivirus epidemic, with a death toll of at least 900 individuals, and there is some concern that this year’s event is yet another instance of that disease:

“Because of the sheer number of animals [dying] over multiple states, people are very concerned that this might be a repeat.” – Trevor Spradlin, marine mammal biologist for the U.S. NOAA National Marine Fisheries Service

Additional concern was expressed that because these bottlenose dolphins are akin to the the “canary in the coal mine” on the coasts that many humans inhabit and eat from, this event may also be an indicator that something very serious may be happening in the oceans, although at this point, no hard data is available on the cause.

Joan Barns, of the Virginia Aquarium, told MSN that because dolphins are social creatures, if these deaths are due to a communicable disease, it could spread quite quickly.

“If it is a virus, then deaths could be tied to weakened immune systems that allowed something else to kill off the animals. Unraveling what is happening can be quite complex.” – Barns

This post was originally published in TreeHugger.

Photo Credit: Thinkstock

73 comments

Jim Ven
Jim Ven10 months ago

thanks for the article.

Carrie-Anne Brown

so sad but thanks for sharing

Silvia Steinhilber

Mass deaths don't happen for no reason. It's just a matter of which one of the devastating things mankind has done is causing this.

Jacqueline Fonseca

We NEED to stop slaughtering the ones in Japan! We NEED to stop polluting their homes, and STOP making them perform for "entertainment"! Wee NEED to stop over fishing their food supply and start respecting their space, home and environment! Thank you TreeHugger for sharing this!

Pat B.
Patty B.3 years ago

Could be a virus or pollution. Or oil spills in the ocean .or the fact that humans are destroying environments .live lightly and take what you need and no more. Stop buying china crap at china mart.

Ruhee B.
Ruhee B.3 years ago

Agree with you Fi T

Fi T.
Fi T.3 years ago

Stop disturbing their life and home

Shirley S.
Shirley S.3 years ago

What with the combination of oil pollution & underwater sonar our sea creatures are DOOMED!

Glenda L.
Glenda L.3 years ago

Creepy. It's probably our fault somehow.

Dee H.
Daphne H.3 years ago

See them safe