Longspine thornyhead (Sebastolobus altivelis) COSEWIC assessment and status report: chapter 10
Existing Protection or Other Status Designations
Management of longspine thornyhead in Canada is guided by a fishery management plan (DFO 2007). TACs (total allowable catches) broken down by area and fleet are in place for longspine thornyhead; although the basis for these is not given in the management plan, these are adjusted as experience with this new fishery develops (J. Rice[1], personal communication). There is 100% observer coverage of the trawl fleet, which takes most of the TAC for longspine thornyhead, and electronic monitoring of catch composition and biological characteristics on all vessels targetting groundfish which do not carry observers.
Based on evidence of declining CPUE off the WCVI, DFO management changed the management regime by spreading effort from existing areas in 2000. The WCVI quota was effectively reduced by half (Table 4), and exploration further north was encouraged (Schnute et al. 2004). In 2002, further measures were introduced by requiring more frequent biological sampling and by creating five longspine thornyhead management regions (Figure 4). The Flamingo area was closed to all trawl tows targetting longspine thornyhead. Despite rough bottom topography in this region, trawl records indicate that longspine thornyheads occur in Flamingo. In that sense, this area may represent a refugium; however, it is not known whether individuals in this area contribute significantly to the recruitment in other areas. Given the long planktonic phase of the larvae and juveniles, populations in Flamingo might “rescue” surrounding areas.
The bottom topography in the area known as Triangle appears even rougher than that in Flamingo. Although Triangle has no official protection, trawl tows do not occur here. There is no information on whether longspine thornyhead populations exist in this region.
No agency has currently listed Sebastolobus altivelis for species-at-risk concern. However, the IUCN Red List of Threatened Species has listed its congener S. alascanus (shortspine thornyhead) from the US west coast with rank EN A2d, or Endangered (high risk of extinction in the wild in the near future), based on an expected population depletion of at least 50% due to exploitation within the next 10 years or 3 generations, whichever is less. On the BC coast, shortspine thornyheads appear ubiquitous and presumably abundant. Fishermen generally catch them as bycatch when targetting other species. DFO constrains this bycatch through individual vessel quotas (IVQs).
[1] Jake Rice, Director, Canadian Science Advisory Secretariat, DFO, Ottawa, Ontario.
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