Changes

There is some evidence which suggests the distribution and migratory patterns of blue whales may have changed in at least four areas: northern Norway, southern Japan, eastern Aleutian Islands, and northern California.

There is some evidence which suggests the distribution and migratory patterns of blue whales may have changed in at least four areas: northern Norway, southern Japan, eastern Aleutian Islands, and northern California.

In northern Norway (ie. Finnmark, Bear Island, and Svalbard) the paucity of sightings during recent surveys along the coast where blue whales were common in the late 1800s and early 1900s, may suggest that the historic distribution has changed (Christensen et al., 1992). However, it could also indicate depletion of the population by whaling.

In northern Norway (i.e. Finnmark, Bear Island, and Svalbard) the paucity of sightings during recent surveys along the coast where blue whales were common in the late 1800s and early 1900s, may suggest that the historic distribution has changed (Christensen et al., 1992). However, it could also indicate depletion of the population by whaling.

In the western North Pacific, the lack of blue whales off southern Japan today may also suggest that the distribution of these animals has changed or that the animals of this region have been extirpated. South of the eastern Aleutian Islands (160ºW and 180ºW), relatively large concentrations of blue whales were documented in the 1970s but the species appears rare there today, suggesting that illegal and unreported whaling depleted the population (Stewart et al., 1987 and Forney and Brownell, 1997).

In the western North Pacific, the lack of blue whales off southern Japan today may also suggest that the distribution of these animals has changed or that the animals of this region have been extirpated. South of the eastern Aleutian Islands (160ºW and 180ºW), relatively large concentrations of blue whales were documented in the 1970s but the species appears rare there today, suggesting that illegal and unreported whaling depleted the population (Stewart et al., 1987 and Forney and Brownell, 1997).

Off northern California (eg. Farallon Islands, Moss Landing, and Trinidad), the recent appearance of numerous blue whales is noteworthy in light of their rarity in these regions prior to the late 1970s. Calambokidis (1995) concluded that such changes in distribution reflect a shift in feeding from the more offshore euphausiid, Euphausia pacifica, to the primarily "neritic" euphausiid, Thysanoëssa spinifera.

Off northern California (e.g. Farallon Islands, Moss Landing, and Trinidad), the recent appearance of numerous blue whales is noteworthy in light of their rarity in these regions prior to the late 1970s. Calambokidis (1995) concluded that such changes in distribution reflect a shift in feeding from the more offshore euphausiid, Euphausia pacifica, to the primarily "neritic" euphausiid, Thysanoëssa spinifera.

===Population Trends===

===Population Trends===

Illegal whaling for blue whales has been documented or is likely to have occurred in the North Pacific, North Atlantic, and Southern Hemisphere. A small number of illegal kills of blue whales have been documented in the Northern Atlantic off Canada and Spain, and in the eastern North Atlantic. Blue whales were also killed in the Southern Hemisphere by the Soviet Union after 1966 (Zemsky et al., 1995a, 1995b). Some illegal whaling by the USSR also occurred in the North Pacific (Yablokov, 1994); it is likely that blue whales were among the species taken by these operations, but the extent is not known.

Illegal whaling for blue whales has been documented or is likely to have occurred in the North Pacific, North Atlantic, and Southern Hemisphere. A small number of illegal kills of blue whales have been documented in the Northern Atlantic off Canada and Spain, and in the eastern North Atlantic. Blue whales were also killed in the Southern Hemisphere by the Soviet Union after 1966 (Zemsky et al., 1995a, 1995b). Some illegal whaling by the USSR also occurred in the North Pacific (Yablokov, 1994); it is likely that blue whales were among the species taken by these operations, but the extent is not known.

No aboriginal whaling for blue whales is known to exist. Aboriginal hunters who target whales off the coast of the Lesser Antilles and Greenland do not target blue whales. Further, Norwegian whaling operations target only minke whales, and the commercial whaling stations in Iceland, Spain, and the Portugese islands of the Azores and Madeira remain officially closed.

No aboriginal whaling for blue whales is known to exist. Aboriginal hunters who target whales off the coast of the Lesser Antilles and Greenland do not target blue whales. Further, Norwegian whaling operations target only minke whales, and the commercial whaling stations in Iceland, Spain, and the Portuguese islands of the Azores and Madeira remain officially closed.