Flounder: Arrowtooth

Turbot

Flatfishes are a distinct group in the order Pleuronectiformes, comprising eleven families with more than 500 species worldwide. Flounders, soles, turbots, halibuts, sanddabs, plaices, and tonguefishes (true soles) are all flatfish. Flatfishes of Pacific waters consist of two broad groups where one includes the flounder families Paralichthyidae, Bothidae (left-eyed) and Pleuronectidae (right-eyed), and the other, the sole family Cynoglossidae and tonguefishes. In Pacific coast seafood markets, many species of flounder are mistakenly referred to as soles. For the purpose of this report, however, common/market names are used (e.g. petrale sole) to help readers.

Arrowtooth flounder exhibit fast-growth and early maturity. These life history characteristics make Arrowtooth flounder a “low” conservation concern.

Arrowtooth stock assessments in 2001 showed no signs of overfishing occurring but the stock status and maximum sustainable yield are unknown. This uncertainty makes the Canadian Pacific Arrowtooth flounder stock status a “moderate” conservation concern.

There is little doubt that the discarding and relocation of ~9000 t/year of biomass taken by bottom trawls will to some degree alter the normal ecological pathways. However, due to the complexity of the marine ecosystem combined with the lack of ecosystem-based studies there is presently no evidence to indicate any changes in the ecosystem structure due to discarding. This factor receives an “unknown” bycatch ranking.

The commercial trawl for Arrowtooth flounder is very wide-spread impacting habitat over a large spatial scale. Much of this habitat includes soft-bottom substrates and a variety of other substrates. It is worth noting that these areas have been trawled for two to six decades and therefore many of the non-resilient species would have largely disappeared prior to the beginning of the observer program in 1996. An introduction of individual vessel quotas have decreased fishing effort but may increase the concentration of fishing effort in a given area. There is little doubt that the capture of ~40 000 t of biomass per year by bottom trawling in Canada’s Pacific waters has wide ranging ecosystem impacts. The alteration of bottom habitat and trophic changes from the biomass removal itself will impact the ecosystem structure. Understanding these impacts in Canadian waters has not yet been properly investigated and therefore it is unknown whether large scale ecosystem state changes have occurred from trawling. Overall the habitat and ecosystem effects from trawling for Arrowtooth flounder in the Canadian Pacific is of “high” conservation concern.

Arrowtooth flounder has only recently become valuable and therefore there has not been a long standing management track record. The Department of Fisheries and Oceans (DFO) plans to develop a credible stock assessment but has not yet been carried out. Overall, relative to most fisheries in the world, this fishery receives regular scientific monitoring. The shortcoming at present time is the timely use of these data in the application of developing a proper stock assessment. Before the 2005 fishing season, this species received little or no management attention. DFO groundfish science and management was unprepared for the sudden interest in this species and placed an in-season Total Allowable Catch(TAC) of 20 000 t on Arrowtooth flounder. This TAC is not based on any scientific stock assessment and so is considered a great conservation concern. Overall, the lack of a management plan, stock assessment, and effort to control bycatch makes the Canadian Pacific Arrowtooth flounder fishery management “high” conservation concern.

Where was this Arrowtooth flounder caught?

Arrowtooth flounder caught in the Canadian Pacific should be avoided. Those caught in the U.S. Pacific are a concern and should be consumed conservatively.

No.