Dolphins, Whales and Porpoises: 2002-2010 Conservation - IUCN
Dolphins, Whales and Porpoises: 2002-2010 Conservation - IUCN
Dolphins, Whales and Porpoises: 2002-2010 Conservation - IUCN
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Chapter 4<br />
Status of Cetacean Species <strong>and</strong> Selected<br />
Populations<br />
This section has been updated <strong>and</strong> revised to reflect new<br />
information that has become available since publication of<br />
the previous Cetacean Action Plan in 1994. Further details<br />
on some of the species <strong>and</strong> populations are available<br />
through the <strong>IUCN</strong> Red List (Hilton-Taylor 2000 or website<br />
at www.redlist.org). A note about referencing in this chapter:<br />
We have sought to achieve a balance between the extremes<br />
of (a) providing a thorough review of the relevant<br />
literature (which is beyond the scope of this publication)<br />
versus (b) providing no citations to justify statements <strong>and</strong><br />
direct readers to sources. We have placed a premium on<br />
authoritative sources published since 1994 <strong>and</strong> on review<br />
documents that themselves cite the important primary literature<br />
on a species or topic. Readers with access to the 1994<br />
Cetacean Action Plan (Reeves <strong>and</strong> Leatherwood 1994a)<br />
may find it useful to check it for pre-1995 references that<br />
have been left out here to save space.<br />
4.1 Right whales<br />
Bowhead whale, Balaena mysticetus<br />
The IWC recognizes five stocks of this Arctic species.<br />
Range-wide abundance is thought to be in the order of<br />
10,000 individuals, with 8200 (7200–9400) in the Bering-<br />
Chukchi-Beaufort Seas (IWC 1996, based on Zeh et al.<br />
1995), at least 350 in Davis Strait-Baffin Bay (Zeh et al.<br />
1993), 284 ± 49 in Hudson Bay-Foxe Basin (Cosens et al.<br />
1997), 100 or less in Svalbard-Barents Sea (Zeh et al. 1993),<br />
<strong>and</strong> 150–200 in the Okhotsk Sea (Zeh et al. 1993). All<br />
bowhead populations were severely depleted by commercial<br />
whaling, which began in the north-eastern Atlantic in<br />
the 1600s. While the species is not listed as Endangered<br />
globally, the Svalbard-Barents Sea (Spitsbergen) stock is<br />
classified as Critically Endangered, <strong>and</strong> the Okhotsk Sea<br />
<strong>and</strong> Davis Strait-Baffin Bay stocks as Endangered. The<br />
Hudson Bay-Foxe Basin stock is listed as Vulnerable.<br />
The Bering-Chukchi-Beaufort stock continues to be hunted<br />
by indigenous people in Alaska, western Canada, <strong>and</strong> the<br />
Russian Far East (Chukotka). The Davis Strait-Baffin Bay<br />
<strong>and</strong> Hudson Bay-Foxe Basin stocks are hunted by Inuit of<br />
eastern Canada. The hunting in Alaska <strong>and</strong> Russia is regulated<br />
by the IWC in close collaboration with national<br />
agencies <strong>and</strong> regional co-management bodies, while that in<br />
Canada is co-managed by the national government <strong>and</strong><br />
regional bodies created under l<strong>and</strong>-claim agreements<br />
33<br />
(Canada withdrew from the IWC in 1982). The<br />
Bering-Chukchi-Beaufort population has been monitored<br />
intensively for more than 20 years <strong>and</strong> was increasing in the<br />
1980s <strong>and</strong> early 1990s at a rate of about 2–3% per year in<br />
spite of the removals by hunting (Zeh et al. 1995). No data<br />
are available on trends in the other bowhead populations,<br />
but if they are growing, they are doing so only very slowly.<br />
Right whales, Eubalaena spp.<br />
Taxonomy <strong>and</strong> nomenclature of the right whales are in flux,<br />
but there is no doubt that the populations in the North<br />
Atlantic <strong>and</strong> North Pacific oceans are completely isolated<br />
from each other <strong>and</strong> from the population(s) in the Southern<br />
Ocean. Recent genetic evidence supports the recognition of<br />
three species (Rosenbaum et al. 2000).<br />
The North Atlantic population (Eubalaena glacialis) consists<br />
of a remnant of about 300–350 individuals off the east<br />
coast of North America. Some members of this population<br />
migrate annually to a near-shore winter calving ground off<br />
northern Florida <strong>and</strong> Georgia <strong>and</strong> then back northward<br />
through New Engl<strong>and</strong> waters <strong>and</strong> on to summer feeding<br />
areas off south-eastern Canada. Right whales are occasionally<br />
seen in European waters, but the species is close to<br />
extinction in the eastern North Atlantic (Notarbartolo di<br />
Sciara et al. 1998). An intensive long-term effort, based<br />
primarily at the New Engl<strong>and</strong> Aquarium in Boston <strong>and</strong> the<br />
U.S. National Marine Fisheries Service laboratory in Woods<br />
Hole, is underway to monitor the North Atlantic right whale<br />
population, identify risk factors, <strong>and</strong> develop <strong>and</strong> implement<br />
measures to reduce human-induced mortality <strong>and</strong> injury<br />
(Katona <strong>and</strong> Kraus 1999; Right Whale Recovery Team<br />
2000). Recent evidence of decreased survival <strong>and</strong> reproductive<br />
rates indicates that the population may be declining<br />
(Caswell et al. 1999).<br />
The right whale population in the North Pacific (E.<br />
japonica) is also only a tiny fraction of what it was in the<br />
mid-19th century (Scarff 2001; Brownell et al. 2001). On<br />
the east side, the few animals observed are usually alone <strong>and</strong><br />
in scattered locations. The only exception is an area of the<br />
south-eastern Bering Sea where small groups of right<br />
whales (but no calves) have been seen in several successive<br />
years. In the western Pacific, a few hundred right whales<br />
spend the summer in the Sea of Okhotsk between Sakhalin<br />
Isl<strong>and</strong> <strong>and</strong> Kamchatka (Miyashita <strong>and</strong> Kato 1998). Large<br />
unreported kills by Soviet whalers in the 1950s <strong>and</strong> 1960s<br />
may have destroyed any chance of the right whale’s