Detection criteria for managing trawl impacts on vulnerable marine ecosystems in high seas fisheries of the South Pacific Ocean

The United Nations General Assembly resolution 61/105 calls for States to protect vul- nerable marine ecosystems (VMEs), including cold-water corals, from destructive fishing practices in international waters. In response, the developing South Pacific Regional Fishery Management Organisation (SPRFMO) adopted interim measures requiring participating states to assess whether individual bottom fishing activities encounter VMEs, and to prevent significant adverse impacts on VMEs, including requiring vessels to cease fishing and move away from such areas. Criteria were developed to identify VMEs from trawl fishery bycatch data and other available scientific informa- tion. The criteria integrate information about the vulnerable taxa present, their relative abundance as bycatch, evidence from previous fishery interactions in the area, the degree of habitat isolation and an index of taxonomic distinctness. We also analysed observer data from previous fishing by New Zealand vessels to evaluate the use of bycatch thresholds to trigger a move-on rule in the SPRFMO area. A focus on documenting the distribution of vulnerable taxa and habitat associations through the most robust survey and habitat modelling means feasible will facilitate identifying representative spatial closures for long-term protection of VMEs.