Can deep water fisheries be managed sustainably?

Governance of deepwater fisheries has a high profile in the international community, including the explicit attention of the United Nations General Assembly (UNGA). This attention reflects concerns about the sustainability of deepwater fisheries and the fragility of deepwater ecosystems, and concern that there is a gap in the international fisheries governance framework when it comes to deepwater fisheries on the high seas. Deepwater fisheries are considered by Food and Agriculture Organization of the United Nations (FAO) as those fisheries that occur beyond the continental shelf/slope break which typically occurs at about 200 metres (m). The current technological limit of these fisheries is about 2 000 m. However, many species not usually considered as deepwater are fished at depths well above 200 m (e.g. the North Pacific walleye Pollock fishery, one of the world's most productive, occurs over a range of 90- 500 m). According to the FAO statistical database, deepwater fisheries produced 5.9 million metric tonnes (t) in 2004 or less than 4 percent of the total production from fisheries and aquaculture (including freshwater). Most of this catch is of species that generally occur in depths of less than 500 m, and some of the species that account for much of the catch occur in shallow nearshore waters as well as beyond 200 m in depth. Deepwater fisheries should not all be 'painted with the same brush' (or, in other words, hairtails and blue whiting are not the same 'kettle of fish' as orange roughy and oreo dories) as there is a great deal of difference between the species fished in the shallow end of the range of deepwater fisheries, and species that are fished at depths centered below 500 m. Species fished in the shallow end of the range have similar biological characteristics to shelf species. They are productive compared to some deeper water species, such as orange roughy. The discourse about deepwater fisheries would be well served by a common understanding of what constitutes a deepwater fishery and what makes them different from other fisheries. Deepwater fisheries beyond 500 m generally have a history of less than three decades, during which early expectations of sustainable yield have often been too optimistic, the biomass on many fishing grounds has been depleted, and biogenic habitats have been impacted. The deepwater fisheries that have attracted the most attention are those for orange roughy at depths of about 700 m and below. Simply stated, the