Halibut: Atlantic

Halibut

Hirame

Atlantic halibut are the largest of the Atlantic flatfishes. They are widely distributed throughout the North Atlantic Ocean and parts of the Arctic Ocean at depths of 200-500 m. They grow relatively quickly and can live as long as 50 years, growing up to 320kg. However, individuals of this size have likely always been rare. Atlantic halibut are annual batch spawners and are able to release several batches of eggs in a single reproductive season, releasing up to 7 million eggs. Most individuals, however, produce considerably fewer eggs. Spawning occurs in Canadian waters in late winter and early spring. The diet of juvenile halibut (<30 cm) is composed of invertebrates such as krill, small crabs, and shrimp. Fish begin to make up a larger proportion of their diet until they reach approximately 70 cm after which time their diet shifts almost exclusively to other fishes.

In comparison to other commercially caught fish, biological traits of Atlantic halibut are moderately vulnerable to fishing pressure, as they mature at 12 years and can live up to 50 years old. The collapse of the American stocks and low abundance of the Gulf of St. Lawrence stock is evidence that this stock can be easily overfished if sustainable catch limits are not enforced. Atlantic halibut are considered to be “moderately” vulnerable to fishing pressure.

Atlantic halibut have been exploited since the 1830s. Surveys done in 2001 indicated that the stock is overfished and not expected to rebuild in the near future. The stock status of Atlantic halibut is considered a “critical” conservation concern.

Due to the mixed species nature of the Atlantic Groundfish fishery, as well as the gear type used, bycatch and subsequent discarding of unmarketable or otherwise illegal species occurs frequently. In addition, trip limits, a management tool used to regulate catch, forces otherwise market-worthy fish to be discarded. According to the Multispecies Groundfish Fisheries Management Plan, trawlers are required to report all discards and use bycatch reduction devices, however, observer coverage is only about 5% and thus numbers of total discards may be underestimated. Overall the nature of bycatch for the Atlantic halibut trawl fishery is considered of “moderate” concern.

Based on the published literature noting the adverse effects of trawling on the various habitat types where flounders are found, as well as the significant amount of fishing effort along the continental shelf over the last 50 years, it is reasonable to assume that trawling for flatfishes has significantly altered or damaged a large portion of the seabed and the ecosystem. The degree of
recovery from these actions is largely unknown and the effects of these fishing practices on habitats and ecosystems is ranked “severe”.

Managers of Northeastern Groundfish resources assess stocks in an effective and timely basis. Managers require specific mesh sizes and gear types to reduce wasteful discard, as well as implement seasonal and permanent closure areas to reduce trawling impacts. Management has not, however, prevented the extreme declines of many commercially important flatfishes, and is therefore considered only moderately effective.

Where and how was this halibut caught?

No.