It is likely that other deep-sea elasmobranchs show similar patte

It is likely that other deep-sea elasmobranchs show similar patterns. Orange roughy is a deepwater demersal species with an almost

global distribution. It inhabits continental slopes and seamounts from 500–1500 m depths. It is slow-growing and reaches ages exceeding 100 years. Natural mortality in adults is low (estimated at 0.045 year−1 off New Zealand), they mature late (at about 30 years), their fecundity is low relative to most teleost species, and adults do not spawn every year. These characteristics make orange roughy much less productive than most shallower-living commercially fished species. Fishing for orange roughy started in New Zealand waters Pexidartinib in the late 1970s. Subsequently other fisheries developed off southeastern Australia in the late 1980s, in the North Atlantic in 1989, off Namibia in 1995, off Chile in 1998 and in the southwest Indian Ocean (SWIO) in 1999 [80]. New Zealand catches rose steadily through

the 1980s as new populations were discovered, and when the Australian fishery found spawning fish off St Helens Seamount, global catches skyrocketed to over 100,000 t (Fig. 3). Numerous new Ribociclib fisheries followed in the 1990s and early 2000s, the largest occurring off Namibia and SWIO. The New Zealand fishery has dominated global catches, and is the only one that has persisted over time with total catches of more than a few thousand tonnes. Much of this comes from a restricted area of the Chatham Rise east of the main New Zealand islands [81]. Stocks in most other fishing grounds around New Zealand have declined substantially [82], and mirror the global pattern on a smaller

spatial scale. Serial depletion has occurred in some of the seamount-based fisheries, and a number of areas are now closed (Fig. 4). The Australian fishery was very large between 1989 and 1993 when catch rates of spawning fish on St. Helens Seamount were high, but the stocks were rapidly depleted and quotas were progressively reduced [83]. The St. Helens fishery is now closed completely and Australia declared orange roughy a “threatened species” in 2006. A similar situation occurred off Namibia and Chile [84], [85] and [86], where, despite extensive Sitaxentan research and precautionary management objectives, catches could not be sustained, and fisheries are now very small or orange roughy are just bycatch. Similarly, in SWIO, large catches were taken for a short time, with uncontrolled increase in effort in the early 2000s with no management on the high seas, then a sharp drop in catches and catch rates [87]. Sissenwine and Mace [18] noted two patterns in these catch histories. In the first, small stocks were fished down rapidly before effective management could be implemented. In the second, with larger stocks, research initially overestimated stock size, often coupled with non-conservative management practises and “fishing-down” phases, which led to excessive depletion.

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