3. Underlying Issues

3.1 - Use and Trade of Shark Products Generally

The three proposals are based on the assumption that the species will be threatened by international trade, and thus they need to be viewed within the general context of fisheries that target sharks.

Chondrichthyans (sharks, skates, rays and chimaeras) are exploited for their meat, fins, cartilage, leather, oil, teeth, gill rakers and jaws (SSG 1996). They are processed and traded in a wide range of different forms, and these often involve mixed-species products, such as fish meal and fertiliser. Shark meat and fins are the two commodities traded in the largest quantities, with the trade in oil having declined substantially since the advent of synthetic substitutes (TRAFFIC 1996 report).

Nearly all species have valuable fins, with price determined by their colour, size, thickness and "needle" content. Imports of fins into Hong Kong rose steadily until 1988, when the level of trade stabilised (AC 1996). Nevertheless, demand is still high, as evidenced by the rise in dry fin cost from $US 11 to $US41 per kg from 1980 to 1992 (Parry-Jones 1996): dried fins are one of the most expensive fishery products (Walker 1998). There is no data to indicate the volume of fin trade on a species by species basis, and it is currently not possible to identify all species by fins alone (AC 1996). The volume of fin trade may be significantly overestimated by customs figures, as there is significant export and re-export for trade and processing purposes (AC 1996).

Chondrichthyans account for approximately 1% (sharks 0.5%) of the world's fisheries. At present, 26 countries report annual catches greater than 10,000 metric tonnes (Bonfil 1994). Global take has risen from 201,000 mt in 1947 to 730,000 mt (approximately 71 million individuals) in 1994 (SSG 1996).

Sharks are mostly caught as by-catch in fisheries targeting teleost species, making it difficult to assess the status and changes in stocks. In the past, most shark catch was discarded, but there are trends towards greater utilisation and more specific targeting of shark species as demand for shark products grows (Marnie & Gruber 1990; Walker 1998). Declines in species caught extensively as by-catch may be difficult to detect, as discards and landings are poorly monitored (SSG 1996). Mortality of incidentally caught sharks, especially from trawl nets and gill nets, may exceed mortality from directed fisheries (SSG 1996).

Early shark fisheries based on long-lived species demonstrate stock depletions occur readily (Walker 1998), but it is often difficult to know when a fishery ends, the relative impacts of population decline and altered markets (C. maximus proposal). The relationships between depletion, risk of commercial extinction and risk of biological extinction are poorly known. The real impact of fisheries is often difficult to quantify, because it is difficult to separate losses due to harvest from movement. Analysis of catch rates of Pacific pelagic sharks by tuna longline did not show any clear change in abundance between 1968–1995 (AC 1996).