Comparison of genetic variability of North and South Atlantic right whales (Eubalaena), using DNA fingerprinting

1997 ◽  
Vol 75 (7) ◽  
pp. 1073-1080 ◽  
Author(s):  
Catherine M. Schaeff ◽  
Scott D. Kraus ◽  
Moira W. Brown ◽  
Judy S. Perkins ◽  
Roger Payne ◽  
...  

The North Atlantic right whale (Eubalaena glacialis) is the most endangered large whale in the world and shows few signs of recovery despite over 60 years of protection. In contrast, the South Atlantic right whale (E. australis), a closely related species, appears to be recovering successfully. Using DNA extracted from skin biopsy samples and two hypervariable minisatellite probes, we compared the levels of genetic diversity within the two populations. Our results revealed that unrelated North Atlantic (NA) right whales exhibit significantly less genetic variation than unrelated South Atlantic (SA) right whales (Jeffreys 33.15 (J33.15) probe: SNA-U-observed = 0.56 versus SSA-U-observed = 0.37, p < 0.01; M13 probe: SNA-U-observed = 0.74 versus SSA-U-observed = 0.46, p < 0.01). The level of band sharing among unrelated North Atlantic right whales was greater than that predicted for second-degree-related South Atlantic right whales (J33.15: SNA-U-observed = 56 versus SSA-2°-expected = 0.53, p < 0.05; M13: SNA-U-observed = 0.74 versus SSA-2°-expected = 0.60, p < 0.01), indicating that the northern animals have lost a substantial amount of genetic variability. Observed band sharing among North Atlantic first-degree relatives was lower than expected, based on band sharing among unrelated animals (J33.15: SNA-1°-observed = 0.67 versus SNA-1°-expected = 0.78, p < 0.01; M13: SNA-1°-observed = 0.83 versus SNA-1°-expected = 0.87, p = 0.15). This suggests that the matings between closely related individuals that would have resulted in the higher band-sharing values were unsuccessful. These results, in conjunction with behavioral and population data which indicate that North Atlantic right whales may be suffering from reduced fertility, fecundity, and juvenile survivorship, support the hypothesis that inbreeding depression is influencing the recovery of this species.

Oryx ◽  
1982 ◽  
Vol 16 (3) ◽  
pp. 255-262
Author(s):  
Randall Reeves

In the early 1800s the once abundant North Atlantic right whale was believed to be extinct. But by mid-century the species had been ‘rediscovered’, and hunting was resumed until 1918, when the whales were again in trouble. In 1935 all right whales became fully protected by an international convention, and in the 1950s the North Atlantic population was once again ‘rediscovered’. Today, after nearly 50 years of protection and slow recovery, the author assesses the present status of the North Atlantic population. Surveys showed disappointing results until in 1980 a survey of the lower Bay of Fundy (prompted by the threat of an oil refinery being built there) revealed surprisingly high numbers. Another survey in 1981, in which the author also took part, has shown the Grand Manan Island region to be a summer and autumn assembly site for at least several dozen of these endangered whales, including a number of cows and calves. This may be a key area for the North Atlantic right whale's survival.


2004 ◽  
Vol 82 (10) ◽  
pp. 1647-1654 ◽  
Author(s):  
Toolika Rastogi ◽  
Moira W Brown ◽  
Brenna A McLeod ◽  
Timothy R Frasier ◽  
Robert Grenier ◽  
...  

The North Atlantic right whale, Eubalaena glacialis (Müller, 1776), is one of the world's most endangered large cetaceans. It is widely believed that Basque whalers caused the most dramatic decline of this species in the western North Atlantic during the early-16th and 17th centuries. Previous osteological analysis of 17 historic bones suggested that 50% of the Basque harvest consisted of right whales and 50% of bowhead whales, Balaena mysticetus L., 1758. This 50:50 ratio has been used to estimate pre-exploitation population size, which has subsequently formed the basis of recovery goals and plans for the North Atlantic right whale. Genetic analysis of 21 bones, 13 identified as right whales and 8 as bowhead whales through osteological examination, indicates that in fact only 1 bone was a right whale and 20 were bowhead whales. Additionally, preliminary microsatellite analyses of this specimen are not consistent with the hypothesis that whaling resulted in the low genetic variation found in this species today. These results differ from what would be expected based on any previous view of Basque whaling, and raise questions regarding the impact of Basque whaling on this species.


Oceanography ◽  
2021 ◽  
Vol 34 (3) ◽  
pp. 22-31
Author(s):  
Erin Meyer-Gutbrod ◽  
◽  
Charles Greene ◽  
Kimberley Davies ◽  
David Johns

Ocean warming linked to anthropogenic climate change is impacting the ecology of marine species around the world. In 2010, the Gulf of Maine and Scotian Shelf regions of the Northwest Atlantic underwent an unprecedented regime shift. Forced by climate-driven changes in the Gulf Stream, warm slope waters entered the region and created a less favorable foraging environment for the endangered North Atlantic right whale population. By mid-decade, right whales had shifted their late spring/summer foraging grounds from the Gulf of Maine and the western Scotian Shelf to the Gulf of St. Lawrence. The population also began exhibiting unusually high mortality in 2017. Here, we report that climate-driven changes in ocean circulation have altered the foraging environment and habitat use of right whales, reducing the population’s calving rate and exposing it to greater mortality risks from ship strikes and fishing gear entanglement. The case of the North Atlantic right whale provides a cautionary tale for the management of protected species in a changing ocean.


2020 ◽  
pp. 187-192
Author(s):  
Randall R. Reeves

The catch history of the North Atlantic right whales (Eubalaena glacialis) in the western North Atlantic has been studied in a series ofprojects. Data from European archives on early Basque whaling, centred in the Strait of Belle Isle, showed that there were at least a fewthousand right whales in the northern part of the range in the sixteenth century. Data from shore whaling in the eastern United Statessupplemented by British customs data indicated that there were still more than a thousand right whales in the southern part of the range(i.e. south from Nova Scotia) in the late seventeenth century. Right whales were depleted throughout the western North Atlantic by themiddle of the eighteenth century, but small shore whaling enterprises persisted in some areas and pelagic whalers continued to kill rightwhales opportunistically. An increase in alongshore whaling occurred at Long Island (New York) beginning in the 1850s and in North andSouth Carolina, Georgia and northern Florida in the 1870s-1880s. By the start of the twentieth century only a few crews of shore whalersremained active in Long Island and North Carolina, and their whaling efforts were desultory. All evidence points to stock depletion as theprimary reason for the demise of organised whaling for right whales in eastern North America. Recent sightings indicate that some rightwhales travel from the Bay of Fundy and Scotian Shelf far to the north and east, at least occasionally reaching the historic Cape FarewellGround. Areas known to have been used regularly by right whales in the past (e.g. Gulf of St Lawrence, Delaware Bay) are now visitedseasonally by only a few individuals. Recent surveys of Cintra Bay, a historic right whale wintering ground in the eastern North Atlantic,provided no evidence of continued use by right whales.


2019 ◽  
Author(s):  
Oceana ◽  
Holly Lake ◽  
Kim Elmslie ◽  
Lesley Wilmot

Tragically, endangered North Atlantic right whales are killed each year in the watersalong the Atlantic Coast of Canada and the United States. Between 2012 and 2016,human activity killed an average of 5.6 of them every year. In recent years, more right whales are being spotted in the Gulf of St. Lawrence, likely due to the effects climate change is having on the distribution of their food source, and they have experiencedalarmingly high death rates in areas that are busy with commercial fishing activity and shipping traffic.The summer of 2017 was devastating for the population. A total of 17 North Atlantic right whale deaths were reported -12 of them in Canadian waters. The first dead whale was found on June 7 that year and by the end of the month, six had beenfound floating or washed ashore in the Gulf of St. Lawrence. History has repeated itself in 2019. From June to August, eight right whales were found dead in Canadian waters — including four within 48 hours— and four more were found entangled infishing gear.The winter started with much-needed hope and excitement with the birth of seven calves. But given that not every carcass is found, and that the death toll has already exceeded the number of known births, 2019 is yet another year of decline for right whales. What’s more, four of the eight deaths were reproductively active females, of which there are fewer than 100 left. On the surface, these numbers might not seem like much.However, North Atlantic right whales are among the most endangered species on the planet, and 2017 and 2019 have dealt catastrophic blows these animals could have done without. Given that only about 400 of them remain,10 the loss of 28 right whales over the last three years (17 in 2017, three in 2018 and eight in 2019) amounts to seven per cent of the species’ population.The North Atlantic right whale population is teetering on the brink of extinction. Many of the few remaining animals are dying horrible deaths as a result of ship strikes and entanglements in fishing gear. The whales that manage tosurvive injury are often left weak and vulnerable. Scientists have long known, and recent research confirms, that humans continue to cause a high rate of right whale deaths.Every single death deepens the urgency with which we must act to stop the tragedy unfolding in the Atlantic. Many people are working hard to save right whales, but more must be done.The Canadian government must do everything possible to halt this disastrous downturn. If nothing changes, we could witness the extinction of this species.


2006 ◽  
Vol 148 (2) ◽  
pp. 260-272 ◽  
Author(s):  
Kathleen E. Hunt ◽  
Rosalind M. Rolland ◽  
Scott D. Kraus ◽  
Samuel K. Wasser

2011 ◽  
Vol 68 (12) ◽  
pp. 2174-2193 ◽  
Author(s):  
Angelia S.M. Vanderlaan ◽  
R. Kent Smedbol ◽  
Christopher T. Taggart

Commercial fishing gear can potentially entangle any whale, and this is especially true for the endangered North Atlantic right whale ( Eubalaena glacialis ), for which entanglement is second only to vessel strike as being responsible for documented right whale deaths. We use right whale survey data and Canadian fishing-gear deployment data to estimate the relative threat of gear entanglement in a Scotia–Fundy study area and the relative risk of lethal entanglement in the Bay of Fundy and on Roseway Basin, Scotian Shelf, where Critical Habitat has been legislated. We focus on groundfish and pelagic hook-and-line; groundfish gillnet; and crab-, hagfish-, and inshore and offshore lobster-trap gear. Our analyses demonstrate that groundfish hook-and-line gear poses the greatest threat to right whales among the seven gear types analysed during the summer-resident period in Critical Habitat and that gear from the lobster fisheries poses the greatest threat during the spring and autumn periods when whales are migrating to and from Critical Habitat. We suggest that area-specific seasonal closures of some fisheries would reduce threat and risk to whales without unduly compromising fishing interests.


Sign in / Sign up

Export Citation Format

Share Document