Total

381,000

8,242,000

42,800,000

5,070,000

1,120,000

a Modified from May (1979).

b See Table 10.1 for pre-whaling population estimates.

Widespread reductions in large pelagic predator populations caused the commercial fisheries to consider new resources. Based on the diets of the whales species (Fig. 9.6) and their pre-exploitation population sizes, it is estimated that whale consumption of krill was around 190 million tons of krill each year (Table 10.1). After being exploited, it is estimated that whales only consumed around 43 million metric tons of krill (Table 10.2). As argued by the fishing industry from the Soviet Union, the 150 million-ton biomass of krill (Euphausia superba) that no longer was being consumed by whales provided a ''surplus'' that could be harvested by humans.

Consequently, after overharvesting the whales, humans then began targeting their krill prey because of its enormous biomass and dense concentrations in accessible swarms (Table 10.1). Locations of krill as well as other marine species have been identified within statistical fishing areas designated by the United Nations Food and Agriculture Organization for the Indian, Pacific, and Atlantic Ocean sectors in the Antarctic region (Figure 10.4).

The first recorded commercial catch of krill was in 1958-59, with a variable-depth trawl off a Soviet whaling vessel operating in the Atlantic Ocean sector of the Southern Ocean (Fig. 10.5). Between 1961 and 1979, the recorded catches of krill increased over five orders of magnitude, with the most marked changes occurring in the middle 1970s. This increased krill harvesting in the 1970s represents the added participation of Japan in 1971, Chile in 1974, Poland and West Germany in 1975, and Taiwan after 1977. In 1981-1982, just prior to the ratification of the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR), the krill harvest reached a peak at 528,000 tons. Afterward, krill harvesting fluctuated and then decreased markedly along with the diminished fishing pressure from Russia following the collapse of the Soviet Union in 1992.

Again—following the trend for the next most available resource—Antarctic fisheries began focusing on fish species. Antarctic fish species have been reported as potential commercial resources since the early 20th century. However, because of their relative inaccessibility and small biomasses compared to marine mammals, or krill, it was not until the end of the 1960s that Antarctic fish exploitation really began (Fig. 10.6).

Between 1969 and 1970, the Soviet Union harvested more than 403,000 tons of Notothenia rossii at South Georgia (Subarea 48.3) in an area where the total allowable catch for all of the fish species has been estimated to be only 50,000 tons per year (Figs. 10.4 and 10.6). Not surprisingly, Notothenia rossii populations at South Georgia declined rapidly and for the next several years only a few thousand tons of this species were harvested. Shortly afterward, Poland, Bulgaria, and West Germany began extending the finfish fishery along the Scotia Arc in the Atlantic Ocean sector with new target species and, by 1978, more than 150,000 tons of fish (primarily Champsocephalus gunnari with some Notothenia rossii) were being harvested annually.

Similar fishing efforts also have been exerted on the Kerguelen Plateau in the Indian Ocean sector (Fig. 10.4) where, in 1971, about 65% of the 229,500-ton

www.fao.org). The solid line around the Antarctic marine ecosystem represents the approximate position of the Antarctic Convergence (Figs. 7.8 and 8.3) and the northern jurisdictional boundary of the 1980 Convention on the Conservation of Antarctic Marine Living Resources (Antarctic Treaty Searchable Database: 1959-1999 CD-ROM).

www.fao.org). The solid line around the Antarctic marine ecosystem represents the approximate position of the Antarctic Convergence (Figs. 7.8 and 8.3) and the northern jurisdictional boundary of the 1980 Convention on the Conservation of Antarctic Marine Living Resources (Antarctic Treaty Searchable Database: 1959-1999 CD-ROM).

harvest was Notothenia rossii (Fig. 10.6). Low Notothenia rossii catches followed, and the fishery refocused on Champsocephalus gunnari along with Notothenia squamifrons. In 1974 and 1977, these two species accounted for more than 75% of the 101,000 and 90,000 tons that were harvested, respectively. Again, the fish catch far exceeded the total allowable catch, which has been estimated to be only 20,000 tons per year for the Kerguelen Plateau area. Compared to the harvests in the Atlantic and Indian Ocean sectors, the fishing effort in the Pacific Ocean sector has been minor, with annual catches generally less than 100 tons.

By the late 1980s, after the Champsocephalus gunnari and Notothenia rossii stocks had been depleted, new fish species were becoming commercial targets,

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