ELLSWORTH — Responding to the deaths of more than a dozen animals in the past three months, NOAA Fisheries last week declared an “Unusual Mortality Event” for endangered North Atlantic right whales throughout their range along the Atlantic coast, primarily in the Gulf of St. Lawrence region of Canada.
As part of the investigation, NOAA Fisheries is assembling a team of independent scientists to coordinate with the agency’s Working Group for Marine Mammal Unusual Mortality Events and the Department of Fisheries Oceans Canada (DFO) to review the data collected and to determine potential next steps.
Since June 7, 10 right whale deaths have been recorded in Canada – primarily in the Gulf of St. Lawrence – and two in U.S. waters. A third North Atlantic right whale mortality occurred in U.S. waters in April, before the designated Unusual Mortality Event is deemed to have begun.
The 13 recorded whale deaths far exceed the number anticipated by scientists. According to NOAA Fisheries, the combined annual average number of dead whale strandings in the United States and Canada is 3.8.
So far, full necropsy examinations have been conducted on seven of the 12 dead whales, but results are not yet available. Two whale carcasses could not be retrieved.
Several, if not all, of the dead whales showed evidence of injury from ship strikes, entanglement with fishing gear or both. The DFO has imposed speed restrictions on vessels traveling in the western Gulf of St. Lawrence and closed or modified several fisheries in the area to reduce the risk of entanglements.
In the United States, ship speed reduction rules are in effect when large numbers of right whales are present. Vessels at least 65 feet long are required to travel at 10 knots or less while entering or departing ports. This rule was put into place primarily for right whale presence in New England and Mid-Atlantic waters from November through July.
Recreational boaters must stay at least 100 feet away from whales at all times.
Scientists are seriously concerned about the high level of right whale mortalities this year.
According to NOAA Fisheries, in 2011, the western North Atlantic right whale population numbered at least 465 individual animals. Over the past six years, analysis of sightings data suggests a slight growth in population size, to perhaps 500 right whales.
Despite that, North Atlantic right whales remain critically endangered, and with such a small population, the population trend could change quickly.