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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Long-beaked common dolphin,<br />
Delphinus capensis<br />
The long-beaked common dolphin occurs in continental<br />
near-shore tropical <strong>and</strong> warm temperate waters of at least<br />
the Pacific, Atlantic, <strong>and</strong> western Indian oceans (including<br />
Madagascar). In the northern Indian Ocean <strong>and</strong> southeastern<br />
Asia, an even longer-beaked variety replaces D.<br />
capensis, <strong>and</strong> some authors consider it a valid species, D.<br />
tropicalis (van Bree <strong>and</strong> Gallagher 1978; Rice 1998).<br />
Recent morphological evidence indicates that differences<br />
between the two forms are probably clinal, <strong>and</strong> therefore not<br />
species-level (Jefferson <strong>and</strong> Van Waerebeek, <strong>2002</strong>). Although<br />
its known distribution is more restricted than that of<br />
the short-beaked common dolphin, <strong>and</strong> its aggregate abundance<br />
probably much lower, the long-beaked species is not<br />
known to face any major immediate threats to its survival. In<br />
several areas, however, most notably West Africa <strong>and</strong> the<br />
east <strong>and</strong> west coasts of South America, the documentation<br />
of abundance <strong>and</strong> catches is insufficient for proper status<br />
evaluation. There is growing concern about the large<br />
numbers of long-beaked common dolphins killed off Peru<br />
<strong>and</strong> used for human food or shark bait (K. Van Waerebeek,<br />
pers. comm.).<br />
Pygmy killer whale, Feresa attenuata<br />
The pygmy killer whale is widely distributed in tropical <strong>and</strong><br />
subtropical waters worldwide (Figure 17). It appears to be<br />
naturally uncommon, <strong>and</strong> group sizes are generally no<br />
larger than around 30 to 50 individuals. Wade <strong>and</strong><br />
Gerrodette (1993) estimated that there were about 40,000 of<br />
these whales in the eastern tropical Pacific. Because of their<br />
relatively low abundance, even small takes in localized<br />
areas could be significant. However, there is no basis for<br />
serious concern about this species at present.<br />
Short-finned pilot whale,<br />
Globicephala macrorhynchus<br />
This species occurs in tropical <strong>and</strong> warm-temperate<br />
waters worldwide, <strong>and</strong> its distribution extends into<br />
cold-temperate waters in the North Pacific (Bernard<br />
<strong>and</strong> Reilly 1999). Stocks are ill-defined except off<br />
Japan, where two morphologically distinct, allopatric<br />
forms have been identified. The species is<br />
abundant globally, but at least one of the two forms<br />
hunted off Japan is depleted. The northern form,<br />
whose population is estimated at only 4000–5000, is<br />
subject to small-type whaling with an annual national<br />
quota of 50. The southern form, with an<br />
estimated population of about 14,000 in coastal<br />
waters (Miyashita 1993), is subject to small-type<br />
whaling, h<strong>and</strong>-harpoon whaling, <strong>and</strong> drive whaling,<br />
<strong>and</strong> there is an annual national quota of 450.<br />
39<br />
Short-finned pilot whales are hunted by artisanal fishermen<br />
in the Lesser Antilles, especially St. Vincent <strong>and</strong> St.<br />
Lucia, where the combined catch was in the hundreds annually<br />
until at least the mid-1970s. Reliable catch data are<br />
not available for the Caribbean hunts. The species is also<br />
hunted in Indonesia <strong>and</strong> Sri Lanka, but again with no regular<br />
reporting of catch levels. Many short-finned pilot whales are<br />
taken incidentally in fishing gear throughout their range.<br />
Population assessments are needed in areas where directed<br />
hunting takes place or where a large bycatch is known or<br />
suspected. A resident population of pilot whales in the<br />
Canary Isl<strong>and</strong>s is exposed to intensive, <strong>and</strong> thus potentially<br />
disruptive, whale-watching <strong>and</strong> fast-ferry traffic. There are<br />
about 150,000 short-finned pilot whales in the eastern tropical<br />
Pacific (Wade <strong>and</strong> Gerrodette 1993) <strong>and</strong> about a thous<strong>and</strong><br />
in shelf waters off the North American west coast<br />
(Carretta et al. 2001).<br />
Long-finned pilot whale, Globicephala<br />
melas<br />
This species is abundant <strong>and</strong> widely distributed in temperate<br />
to subpolar marine waters. Two subspecies are recognized:<br />
one in the cold temperate <strong>and</strong> subarctic North Atlantic, the<br />
other in temperate to subantarctic waters of the Southern<br />
Hemisphere to as far south as about 68ºS (Bernard <strong>and</strong> Reilly<br />
1999). In the North Atlantic, the species occurs in deep offshore<br />
waters, including those inside the western Mediterranean<br />
Sea, North Sea, <strong>and</strong> Gulf of St. Lawrence. Long-finned<br />
pilot whales tend to follow their prey (squid <strong>and</strong> mackerel)<br />
inshore <strong>and</strong> into continental shelf waters during the summer<br />
<strong>and</strong> autumn.<br />
The southern subspecies has not been exploited on a significant<br />
scale; about 200,000 are estimated to occur in waters<br />
Figure 17. Profile of a pair of pygmy killer whales swimming near<br />
Manado Tua, north-western Sulawesi, Indonesia, August 1998. These<br />
small whales are relatively common in south-eastern Indonesian<br />
waters <strong>and</strong> can sometimes be confused with juvenile Risso’s dolphins.<br />
Photo: Benjamin Kahn.