An unusually high number of dead minke whales reported along the East Coast in the past year has prompted federal officials to launch an investigation into what’s killing the protected animals.
The National Oceanic and Atmospheric Administration announced Wednesday that it declared the strandings of 29 minke whales between Maine and South Carolina since January 2017 an “unusual mortality event.” The designation enables the agency to open the investigation.
The average number of dead minke whales found in U.S. waters in a year is 12, NOAA officials said Wednesday in a conference call.
Of those 29 minke whales, 19 were found dead over the past year. Another 10 animals were found in poor health, of which only one survived.
Nine whales appeared to have died from entanglement with fishing gear; two from blunt-force trauma, presumed to be from ship strikes; and eight from infectious diseases, though investigators have not determined how the diseased animals may have gotten sick.
“We’re still going through the analysis of what might be the cause,” said Teri Rowles, marine mammal health and stranding program coordinator for NOAA Fisheries’ Office of Protected Resources.
The estimated number of minke whales along the East Coast and Atlantic Canada is between 1,400 and 2,500. They are generally smaller than other whales, growing up to 35 feet long and weighing 20,000 pounds.
Minke whales are not listed under the Endangered Species Act but, like all whales, are protected by the Marine Mammal Protection Act.
“The number of mortalities we’ve observed so far are not considered a threat to the population’s sustainability,” Rowles said.
The past two years have been considered deadly for whales in the northwest Atlantic Ocean. Since January 2016, 62 humpback whales have been found dead or in distress in U.S. waters on the East Coast. Since January 2017, 18 north Atlantic right whales have been found dead off the East Coast or Atlantic Canada.
Humpback whales in the north Atlantic, which have an estimated population between 10,000 and 13,500, were de-listed from the Endangered Species Act in September 2016. North Atlantic right whales remain critically endangered, however, with a population of around 430 animals.
NOAA opened investigations last year into the deaths of the humpback and right whales. The three ongoing investigations are separate but could be combined if NOAA finds evidence that deaths among the three species are closely related. Federal regulations on fishing or ship speeds could be modified as a result of the investigations’ findings, officials said.
NOAA officials said they have found no direct connection between the three series of deaths but the respective investigative teams are sharing information.
“Strandings across the three species are not clustering in space or time,” NOAA officials said in a statement. “Part of the goal of the investigations is to determine if there are commonalities in the findings from the three species that could point to a single cause, but as of yet no single cause has been identified.”
NOAA officials said the public can help by promptly reporting any sighting of a dead or stranded whale by calling 866-755-NOAA.
People also can make either financial or in-kind donations to help support the investigations. Additional information can be found online at fisheries.noaa.gov.
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