Dolphins, Porpoises, and Whales - IUCN

of its recovery and the absence of any immediate threat to
its survival, this stock of gray whales was removed from
the U.S. Endangered Species List in June 1994. Most of
the I WC annual catch limit of 178 gray whales is allocated
to Russia for the benefit of aboriginal communities in
Chukotka (Krupnik 1987, Sander 1992).
The gray whale's coastal migration and inshore distribution
in winter create the conditions for conflict with
many human activities. In compaTrison with some of the
more oceanic cetaceans, individual gray whales may be
more vulnerable to disturbance, collisions with fishing
gear (Fig. 8) and vessels, oil spills and other forms of pollution,
and habitat modification or destruction. However,
such problems seem not to have significantly impeded the
eastern stock's recovery from depletion.
Pygmy Right Whale
{Caperea marginata)
This species has a circumpolar distribution in temperate
and subantarctic waters of the Southern Ocean (Baker
1985, Pavey 1992). It is one of the least known of all
cetaceans. Very few pygmy right whales are known to
have been taken (Ross et al. 1975), and no conservation
problems have been identified.
Commerson's Dolphin
(Cephalorhynchus commersonii)
Commerson's dolphin occurs in two disjunct populations:
one in the western South Atlantic including the Falkland
Islands (Islas Malvinas) area and the Strait of Magellan,
and one near the Kerguelen Islands in the southern Indian
Ocean (Goodall 1994a). The South American population
has been subjected to harpooning (mainly for crab bait),
accidental capture in fishing gear, and some live-capture
for oceanaria (Goodall et al. 1988a, Leatherwood et al.
1988b, Ifiiguez 1991b). No good estimates are available
on the magnitude of the catches or on the size of the population.
The fragmentary information available on
exploitation suggests that at least hundreds of Commerson's
dolphins were killed per year during the 1970s
and 1980s in southern Argentina and Chile (IWC 1985,
Goodall et al. 1988a). Leatherwood et al. (1988a) estimated
that there were 3,211 (SE=1,168) Commerson's
dolphins present in the northeastern Strait of Magellan in
early 1984, but subsequent estimates have been much
smaller (cf. Venegas and Atalah 1988). The discrepancies
may be the result of seasonal migrations into and out
of the strait or of differences in estimation methods or
observer experience. More and better data are needed to
assess the conservation status of the South American pop-
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ulation(s) of Commerson's dolphin.
There is no evidence that these dolphins are hunted or
taken on a significant scale in fishing gear around the
Falkland Islands. The Kerguelen papulation is probably
small and would be threatened by the large-scale use of
gillnets in coastal waters, which however does not occur at
present. French observers on board Russian trawlers
working on the Kerguelen plateau have not reported any
incidental kills of dolphins (D. Robineau, pers. comm.).
Chilean Dolphin
{Cephalorhynchus eutropia)
Like other members of this genus, the Chilean dolphin has
a restricted, coastal distribution. Its range is limited to
Chilean coastal waters from approximately 30° S southward
to southern Tierra del Fuego (Goodall et al. 1988b,
Goodall 1994b). The crab bait fishery in southern Chile, in
combination with a variety of other fisheries along the
Chilean coast throughout the species' range, have been
viewed as potentially serious threats to the Chilean dolphin.
However, documentation of the numbers and
species of dolphins actually taken in the various areas and
fisheries is fragmentary (Goodall and Cameron 1980,
Leatherwood e/a/. 1988b). No population estimates are
available for any part of this dolphin's very limited range.
Heaviside's Dolphin
{Cephalorhynchus heavlsldil)
Heaviside's dolphin (Fig. 9) inhabits coastal waters off the
west coast of southern Africa (Best and Abernethy 1994).
It is the most commonly sighted dolphin in Namibian
waters (M. Griffin, Directorate of Wildlife, Conservation
Figure 9. Heaviside's dolphin is a coastal species endemic to the
southwestern coast of Africa. Little is known about its life
history, ecology, and population size.