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3.4 COMMENTS


There are several reasons for regarding the above figures as great underestimates of actual chondrichthyan catches. This is due to the lack of reporting, in particular on stocks incidentally captured as bycatch or discarded at sea, as well as on those taken by recreational, subsistence and artisanal fisheries. FAO catch data are from commercial, industrial, recreational, subsistence and artisanal fisheries but the last three categories are likely to be substantially under reported. In some areas, for example in the USA, recreational fishers contribute a significant percentage of total national catches and landings of chondrichthyan species. Moreover, there are countries, such as China (mainland) that do not report any catches or landings of chondrichthyans to FAO. In the case of China there are estimates from Bonfil[14], based on shark fins exports to Southeast Asian countries[15], that indicate an increase in Chinese shark catch from less than 100 tonnes in 1981 to between 17 000 and 28 000 tonnes in 1991. The Bureau of Fisheries provided data on Chinese elasmobranch catches in response to Notification number 884 from the Secretariat of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). According to this data, total landings of sharks are between 4 000 and 7 000 tonnes per annum. However, there are other estimates of 22 500 tonnes for Chinese landings of sharks[16].

In addition to being directly targeted in various commercial and recreational fisheries throughout the world, a great number of sharks and other chondrichthyans are landed from multi-species fisheries or taken as bycatch in fisheries targeting other species such as tuna, swordfish, shrimps, squid and other species all over the globe. They are usually thrown back, unrecorded, into the sea. The long-line fisheries for tuna of Japan, Korea and Taiwan Province of China account for most of this bycatch. Many countries do not report the enormous numbers of sharks taken as bycatch. Like other aspects of shark fisheries, incidental capture is very poorly documented. According to Bonfil[17], the estimated annual elasmobranch bycatch at the end of the 1980s was between 260 000 and 300 000 tonnes or 11.6-12.7 million fish, of which the greater part were sharks, mainly blue sharks. About 80% of the estimated total elasmobranch bycatch by weight and about 70% by number of fish came from longline fisheries. Table 4 shows Bonfil’s reported estimates, of which, according to him, 4 075 162 were blue sharks.

Table 4 Selected estimates of shark taken as bycatch by longline, high seas fisheries

Area

Number of individuals

Total catch in tonnes

Atlantic Ocean

2 305 940

76 318

Indian Ocean

1 931 574

75 180

South/Central Pacific Ocean

1 996 350

39 927

North Pacific (above 20°N)

2 050 135

41 000

Total

8 283 999

232 425

Source: Table 2.21. page 96, Bonfil.

According to Bonfil[18], the former high seas drift-net fisheries ranked second in their contribution to the elasmobranch bycatch. Since the end of 1992 their activities were stopped due to the moratorium on the use of large-scale drift-nets. In the late 1980s observers recorded that over 20 000 blue sharks were caught annually by California drift-net fisheries alone. More than 80% of the bycatch of the drift-net fleet of Taiwan Province of China were sharks. Total elasmobranch bycatch in purse-seine fisheries has been estimated at 6 345 tonnes for 1989[19].

Discards from high seas fisheries are also high. According to Bonfil[20], up to 230 000-240 000 tonnes of Elasmobranchii are discarded annually by various high seas fisheries. The amount of discarded stocks and survival rates of released sharks are uncertain. Depending upon the fisheries, sharks may or may not be retained. Discarded sharks may or may not survive, depending upon the type of gear, the species, and whether the fins are removed before discarding. For instance, most discards, certainly those caught by the drift-net, purse-seine and orange roughy fisheries, generally do not survive. Some species of sharks may survive when hooked on longlines if the fishermen release sharks quickly and unharmed. Other species that must maintain movement are less likely to survive. In the past sharks were usually released or discarded and there are reports that indicate that around 66% of the discards survived[21]. By the late 1980s the increase in price and demand for the fins caused the previously released or discarded sharks to be retained as bycatch or, more usually, to be brought on board to be finned. Finning is the name given to the practice of capturing sharks, cutting off their fins and throwing them back, often still alive, into the water. Although the main market for fins is Asia where they are made into shark fin soup, the demand for fins is on the increase elsewhere. Finning is especially attractive because the fins can be dried easily, and stored without expensive on-board preparation and refrigeration equipment. Poor fishermen can get into the game, and large fleets can increase their profits with little effort. Finning occurs legally all over the oceans, with the exception of the Atlantic waters off Canada and the USA, in Californian state waters, in Oman and South Africa.

Taking all the under-estimates reported above together, Bonfil[22] estimated that the actual total catch of sharks, batoids and chimaeras was about 1 350 000 tonnes in 1991 or nearly twice FAO’s reported catch statistics for that year. This figure includes the estimated catch of the People’s Republic of China and the catch from large-scale high seas fisheries previously seen, and estimates of the mortality of sharks in recreational fisheries. All indications are that the data on shark have not improved over time and therefore the total catch of sharks can again be estimated at twice the recorded catch, which means nearly 1.6 million tonnes in 1997.


[14 ]BONFIL R., idem.
[15 ]WONGSAWANG P., Southeast Asian Fisheries Development Center (SEAFDEC), pers. comm., “Fisheries statistical bulletin for the South China Sea area, Thailand 1992.
[16 ]PARRY-JONES R., "TRAFFIC report on shark fisheries and trade in the People's Republic of China", in "TRAFFIC report on shark fisheries and trade in the East Asian region", of the "The world trade in sharks: a compendium of TRAFFIC's regional studies volume I", TRAFFIC, 1996.
[17 ]BONFIL R., idem.
[18 ]BONFIL R., idem.
[19 ]BONFIL R., idem.
[20 ]BONFIL R., idem.
[21 ]BERKLEY S.A and CAMPOS W.L., “Relative abundance and fishery potential of pelagic sharks along Florida’s east coast”, Marine Fisheries Review, 1988.
[22 ]BONFIL R., idem.

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