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Dolphins, Whales and Porpoises: 2002-2010 Conservation - IUCN

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time), they had not yet attained 80% of those levels. Importantly,<br />

the large illegal kills by Soviet factory ships in the<br />

Southern Hemisphere from the 1950s to the early 1970s<br />

would have delayed recovery of southern stocks.<br />

4.3 Gray whale<br />

Gray whale, Eschrichtius robustus<br />

The gray whale was extirpated from the North Atlantic<br />

within the last 300–400 years, so the only extant representatives<br />

of the family Eschrichtiidae are the gray whales<br />

in the North Pacific. The western Pacific stock, which may<br />

number no more than about 100 individuals, was reclassified<br />

in the 2000 <strong>IUCN</strong> Red List from Endangered to<br />

Critically Endangered (under the 1996 categories <strong>and</strong><br />

criteria). Its principal summer feeding area is off Sakhalin<br />

Isl<strong>and</strong> in the Russian sector of the Okhotsk Sea, where a<br />

major oil <strong>and</strong> gas field is being developed by a multinational<br />

energy consortium (Weller et al. <strong>2002</strong>). The annual migration<br />

takes these whales into coastal waters of Japan,<br />

Korea, <strong>and</strong> China, where they are vulnerable to ship collisions<br />

<strong>and</strong> entanglement in fishing gear. Moreover, a female<br />

from this population was found on a Japanese beach in<br />

1996 bearing several harpoons of the kind used in the Dall’s<br />

porpoise hunt off Japan (Brownell <strong>and</strong> Kasuya 1999; Baker<br />

et al. <strong>2002</strong>). This incident demonstrates that the western<br />

Pacific population is at risk from illegal hunting.<br />

The eastern stock of more than 21,000 has been growing<br />

steadily in spite of an annual hunt in Russia governed by an<br />

IWC quota (Buckl<strong>and</strong> <strong>and</strong> Breiwick <strong>2002</strong>). In recent years,<br />

however, this population has experienced an unprecedented<br />

amount of mortality on its migration route <strong>and</strong> in the winter<br />

breeding areas, <strong>and</strong> exhibited a decline in calf production<br />

(Le Boeuf et al. 2000). There is concern that these trends,<br />

should they persist, could lead to a significant decline in<br />

abundance of the eastern Pacific stock.<br />

4.4 Pygmy right whale<br />

Pygmy right whale, Caperea marginata<br />

The pygmy right whale is thought to have a circumpolar<br />

distribution in temperate <strong>and</strong> subantarctic waters of the<br />

Southern Ocean. It is one of the least known cetacean<br />

species, although recently completed anatomical studies<br />

(Kemper <strong>and</strong> Leppard 1999) <strong>and</strong> observations at sea (e.g.,<br />

Matsuoka et al. 1996) have begun to reveal basic information.<br />

There are no known conservation problems (Kemper<br />

<strong>2002</strong>).<br />

37<br />

4.5 Marine dolphins<br />

Commerson’s dolphin,<br />

Cephalorhynchus commersonii<br />

Commerson’s dolphins occur as two disjunct populations.<br />

The larger is centered in coastal <strong>and</strong> inshore waters of the<br />

western South Atlantic, including Patagonia, the Strait of<br />

Magellan, Tierra del Fuego, <strong>and</strong> the Falkl<strong>and</strong> Isl<strong>and</strong>s (Las<br />

Malvinas). Some individuals move south through Drake<br />

Passage as far as the South Shetl<strong>and</strong> Isl<strong>and</strong>s. The other<br />

population inhabits coastal waters around the Kerguelen<br />

Isl<strong>and</strong>s in the southern Indian Ocean (Goodall 1994).<br />

The species’ near-shore distribution makes it vulnerable<br />

to incidental capture in gillnets <strong>and</strong> other fishing gear used<br />

in coastal waters. Commerson’s dolphins are killed at least<br />

occasionally in mid-water trawl nets on the Argentine shelf<br />

(Crespo et al. 1997). The South American population has<br />

also been subjected to harpooning (mainly for crab bait) <strong>and</strong><br />

some live-capture for oceanaria (Lescrauwaet <strong>and</strong> Gibbons<br />

1994). No good estimates are available on the magnitude of<br />

the catches, but recent surveys indicate that the species is<br />

still relatively abundant on the Patagonian shelf <strong>and</strong> in the<br />

Strait of Magellan (Lescrauwaet et al. 2000; Crespo, unpublished<br />

data).<br />

Chilean dolphin, Cephalorhynchus<br />

eutropia<br />

The Chilean dolphin is endemic to coastal waters of Chile,<br />

from near Valparaíso (33°S) south to Navarino Isl<strong>and</strong> near<br />

Cape Horn (55°15’S). It is relatively common in the channels<br />

of Chile’s convoluted coastline south from Chiloé<br />

Isl<strong>and</strong>. The crab bait fishery in southern Chile (cf.<br />

Lescrauwaet <strong>and</strong> Gibbons 1994) <strong>and</strong> a variety of other<br />

fisheries (particularly coastal gillnet fisheries) have been<br />

viewed as potentially serious threats. Some shooting <strong>and</strong><br />

harpooning also occurs, with the dolphins used for bait or<br />

human consumption. Unfortunately, there is no systematic<br />

monitoring of either mortality or abundance, so the species’<br />

status is uncertain. In addition to the mortality caused by<br />

entanglement <strong>and</strong> hunting, Chilean dolphins may now be<br />

excluded by salmon aquaculture operations from some of<br />

the bays <strong>and</strong> fiords that they traditionally inhabited (Claude<br />

et al. 2000).<br />

Heaviside’s dolphin,<br />

Cephalorhynchus heavisidii<br />

Heaviside’s dolphins have an extremely limited range<br />

(Figure 16). They occur only in coastal waters off the west<br />

coast of southern Africa, from near the Angola-Namibia<br />

border (at about 17°S) south to Cape Point, South Africa<br />

(near Cape Town). They are said to be the most commonly<br />

sighted dolphins in Namibian waters. There is no clear

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