North Atlantic right whale
The North Atlantic right whale was listed under the Species at Risk Act in 2005. An expert team headed by Fisheries and Oceans Canada developed this recovery strategy, in light of current knowledge and inspired from the right whale recovery plan (WWF/DFO, 2000). The recovery of the North Atlantic right whale will require international collaboration and cooperation.
What follows is a summary prepared by Whales On Line.
North Atlantic right whales are typical of long-lived species, maturing late and producing fewer but larger young. Long intergenerational time intervals and low annual reproductive rates make the species vulnerable to increased mortality. Furthermore, the low genetic diversity observed in this species undermines its reproductive success.
The North Atlantic right whale was decimated and pushed to the brink of extinction by commercial whaling, which began in North America with the arrival of the Basques in the 16th century and ended in the 1930s. Although this species no longer suffers from hunting pressure, it faces other threats such as:
- Ship strikes
- Bycatch in fishing gear
- Disturbance related to the presence of boats
- Changes in food resources
Due to the lack of precise data on historic abundance, it is not possible to set a long-term target. However, in light of current knowledge of the status and trends of the population, it is possible to establish interim targets. The interim recovery objective is thus to achieve “an upward trend in abundance over three generations”, or a minimum period of approximately 60 years.
The seven recovery objectives to achieve this target are:
- Reduce mortality and injuries caused by ship strikes
- Reduce the frequency and seriousness of bycatch in fishing gear
- Reduce human-induced disturbance
- Conduct population monitoring
- Promote research to better understand the species and the threats it faces
- Support and promote collaboration amongst different stakeholders
- Develop and implement awareness and stewardship activities
Mortality caused by ship strikes is considered the number one threat to the survival of North Atlantic right whales. Between 1991 and 2007, collisions were responsible for half of all mortalities in this species. Why do these collisions threaten right whales in particular? Firstly, they are very slow swimmers, so the speed at which they can change their course is limited. Further, the species frequents heavy maritime traffic regions such as the East Coasts of Canada and the United States. Measures have nonetheless been adopted in Canadian and US waters, for example the rerouting of shipping lanes in the Bay of Fundy, which has reduced the risk of collision by 90% in this area.
It is still unknown how right whales detect ships and other obstacles. There is strong evidence that their hearing range encompasses the frequencies produced by ships, unless high-frequency sounds such as those produced by powerful propellers lie outside of the whales’ audible frequency range. And the fact that the sounds emitted by most ships travel toward the stern and the sides – the area ahead of the bow certainly being the quietest – might explain why North Atlantic right whales do not always manage to avoid approaching vessels. It is also argued that, owing to its longevity, the right whale has not had the chance to adopt a new behaviour in the presence of ships, given that maritime traffic is a relatively new element of its habitat and that vessels have increased in speed over the past few decades. Lastly, other factors that interfere, mask or modify sounds travelling in the oceans might also play a role: sound refraction at the water’s surface, echoes off rocky seabeds and other sounds emitted in the water./p>
Bycatch in fishing gear
Between early June and late November, North Atlantic right whales frequent a number of sectors where fixed fishing gear is installed. Over 75% of North Atlantic right whales, young individuals especially, show injuries or scars caused by fishing gear. Buoy ropes, gillnet panels, floating longlines and ghost nets are most often involved, but right whales have also been reported to run afoul of longlines, cod traps and herring weirs. They usually get caught by the mouth, fins or tail. Some of these entanglements can result in the animal’s death. Whales can survive however with lines wrapped around their bodies, occasionally dragging nets, lines, buoys or traps for months or even years on end. The weakening caused by infected injuries as well as the loss of efficiency for swimming, diving, hunting and other behaviours are difficult to measure. Efforts to disentangle whales in Canada and the United States have allowed several trapped individuals to be freed, but such interventions are arduous, often unsuccessful and do not guarantee that the animal will survive.
The North Atlantic right whale feeds almost exclusively on copepods, a planktonic animal the size of a grain of rice. Since these animals are found at the base of the food chain, the right whale has less of a tendency to accumulate large concentrations of contaminants compared to whales that prey on fish, which are higher on the food chain. Conversely, the areas frequented by this species (Gulf of St. Lawrence and East Coasts of Canada and the United States) happen to be areas heavily exposed to pollution. Concentrations of organochlorine hydrocarbons in the Bay of Fundy are relatively high and heavy metal levels (lead, mercury, cadmium) are significant. Organochlorine composites, in particular toxaphene, DDT and PCBs, have been found in the fat of North Atlantic right whales, though not in concentrations considered to be of concern. The effects of chemical contamination, nutrient enrichment of water, sedimentation, and other forms of habitat degradation are difficult to document and assess. Nevertheless, recent studies on the levels of contaminants in the Bay of Fundy clearly indicate that there is cause for concern.
North Atlantic right whales depend on sounds to communicate with one another and noise of human origin can hinder this communication. Chronic exposure to noise can also cause temporary or permanent auditory problems. In Canada, in the habitat parcels most frequented by right whales, the most worrying sources of noise currently include commercial vessels and whale-watching boats, oil and gas prospecting, military testing, use of acoustic harassment devices installed on fishing gear to keep other marine mammals away, offshore construction, and sonar devices used for commercial, scientific and military purposes.
Disturbance related to the presence of boats
The presence of watercraft in right whale habitat, regardless of their size or function, raises a number of concerns. In addition to noise pollution and the risk of collisions, these boats can modify right whale behaviour, for example by disturbing social interactions or nursing, or even driving them away from nutrient-rich waters.
Changes in food resources
Inadequate food resources can lead to (i) a reduction in animals’ growth rates, prolonging the time required to reach sexual maturity, and/or (ii) a deficiency in the fat reserves needed by females for gestation or nursing, potentially resulting in increased calf mortality. At the present time, it is not known whether these changes are taking place. Researchers monitor different indicators such as the thickness of the blubber layer, the shape of the back and fluctuations in the number of young observed from year to year.
1. Reduce mortality and injuries caused by ship strikes
There is no easy solution to the issue of ship strikes. Even if captains have no intention of injuring or killing right whales, accidents nevertheless can and do occur. Proposed solutions include conducting in-depth analysis of the relationship between North Atlantic right whales and maritime traffic, reducing potential overlap, and building on collaboration and voluntary measures with captains and seamen to minimize collisions.
2. Reduce the frequency and seriousness of bycatch in fishing gear
This objective implies both a reduction of the seriousness of incidental catches and measures to prevent them in the first place. It is obvious that fishermen have a front-line role to play in that they have a vested interesting in preventing whales from getting ensnared in their fishing nets, as such incidents damage their material and compromise the profitability of their operations.
3. Reduce human-induced disturbance
Given the small size of the North Atlantic right whale population, risks related to human activities should be assessed with caution. Each individual’s heath can be important for the survival of the population. This strategy comprises two major elements. First, it consists of using all available information as well as common sense to act in a preventive manner to reduce potential disturbance to right whales. Second, it entails studying and better understanding potential sources of disturbance and developing means of reducing them further.
4. Conduct population monitoring
Knowledge of the health of the population and its range in Canadian waters is insufficient. The North Atlantic right whale population requires monitoring, as do the nature and magnitude of the key threats to the species.
5. Promote research to better understand the species and the threats it faces
Research on North Atlantic right whales did not truly begin in earnest until the early and mid-1980s. Despite the knowledge gained over the years on the biology, behaviour and status of the species, many aspects are still poorly understood. To advance our knowledge on right whales, certain monitoring and research projects must be pursued and others must be initiated. Researchers must coordinate their efforts and cooperate as much as possible in light of the magnitude and scope of information needed. Canadian organizations and researchers should work in close collaboration with their counterparts in the United States and, if necessary, Greenland, Iceland and other North Atlantic countries whose waters are frequented by right whales.
6. Support and promote collaboration amongst different stakeholders
The protection and recovery of the North Atlantic right whale is a responsibility shared with regulatory organizations, user groups and communities within the species’ Canadian range. Foreign governments and international organizations are also interested in protecting the species or have responsibilities in this regard. Information exchange between the various stakeholders as well as their conservation efforts, which often take the form of recovery action plans, should be coordinated and formalized as needed.
7. Develop and implement awareness and stewardship activities
Education and awareness efforts are important tools for promoting recovery efforts amongst stakeholders and the general public.