North Atlantic right whales - the threat from vessel strikes
Vessel strikes have been considered the number one threat to the recovery of the North Atlantic right whale and the leading cause of death for the species. Unfortunately, because their habitat is almost entirely in busy coastal areas, their migration across bustling port entrances and their tendency to socialize in groups near the surface make them uniquely vulnerable to being fatally struck by passing vessels.
Right whales are often called “the urban whale” because they are most often found very close to the coastline – typically within 50 miles of the shore. Their migration path takes them along the very busy U.S. Eastern Seaboard twice a year as they travel to their feeding grounds off New England and Southern Canada in the spring and summer, and down to the coasts of the Carolinas, Georgia and Florida for their winter calving areas.
Right whales feed exclusively on zooplankton (tiny marine animals), that are often concentrated at, or near the surface, particularly at night, making it more difficult for vessel operators to see them. These whales are relatively slow swimmers, typically moving at about 2-5 knots with top speed at approximately 8 knots. Most vessels, including both small recreational boats and large commercial tankers will travel much faster, with speeds up to 25 knots or faster. As a result, many whales are unable to avoid approaching vessels. Research has shown that putting sound alarms on ships would actually increase their risk of strike. Trying to escape the sound, the whales immediately swam to the surface when the alarms were sounded, putting them in harm’s way.
As right whales struggle to recover, the loss of even one reproducing female can have devastating consequences for the continued survival of the species. According to the National Marine Fisheries Service (NMFS), the federal agency charged with protecting whales, the “effects of vessel-related deaths on right whale recovery is especially significant because a disproportionate number of ship strike victims are female right whales.” This may be because pregnant females and females with nursing calves spend more time at the surface of the water, where they are more vulnerable to being struck.
There are solutions to this threat: move ships away from areas where whales are known to congregate; or slow them down to 10 knots or less if they must transit through whale habitats. In 2007 the international shipping lanes into Boston were moved to avoid areas of Stellwagen Bank National Marine Sanctuary that were known to be heavily used by large whales in an effort to reduce the impact of vessel strikes. Additionally in 2008, the Cornell Bioacoustics Research Program, in partnership with Woods Hole Oceanographic Institute, the Stellwagen Bank National Marine Sanctuary, and the National Oceanic and Atmospheric Administration, deployed special acoustic buoys within the shipping lanes that detect vocalizations of right whales, called the Right Whale Listening Network. When a right whale is detected, the buoys send a signal that is analyzed by the research lab. Once it has been confirmed as an authentic right whale call, vessel operators are alerted in near real time that right whales are present so they can take appropriate measures to watch out for and avoid right whales.
It was a result of the efforts of WDC in collaboration with the Humane Society of the United States, Defenders of Wildlife and Ocean Conservancy that the 2008 Final Rule to Implement Speed Restrictions to Reduce the Threat of Ship Collisions with North Atlantic Right Whaleswas released and implemented. This rule requires vessels of 20m (65ft) in length or greater to travel no faster than 10 knots in seasonally designated right whale habitats.
However, this rule was released with an unprecedented “sunset clause” and was set to expire on December 9, 2013. In June of 2012, WDC, along with the Humane Society of the United States, Defenders of Wildlife, and Center for Biological Diversity legally petitioned the US government to extend and expand this rule. We are thankful to the more than 70,000 supporters that signed our petition to NOAA, asking them to keep the rule in place. These signatures made up over half of all the comments received by the government, and were instrumental in our success to have the Ship Strike Rule extended permanently.
Since the rule has gone into effect, there have been no documented ship strikes of right whales in the areas when the speed restrictions are in place and the National Marine Fisheries Service's own data estimates that the risk of ship strikes to right whales have declined by 80-90% as a result of the 10 knot speed rule.