Russia working to counter downward trend in halibut stocks
Russian fishery scientists and seafood companies are working on a strategy to safeguard stocks of halibut as the species continues to see declines in total allowable catch.
Earlier this month, Russia’s Ministry of Agriculture rolled out new regulations to limit fishing of the species during its season – which runs for three months beginning in October. The halibut fishery in Russia is relatively small in volume compared to other fisheriesin the country, but its commercial value is high, with chefs in high-end restaurants favoring the species.
In Russia, most halibut are caught in the Sea of Okhotsk and the Bering Sea, with some caught in the Sea of Japan. The catches in the Sea of Okhotsk are dominated by black halibut (Reinhardtius hipoglossoides), while catches in the Bering Sea primarily consist of Pacific halibut (Hippoglossus stenolepis).
Multiple factors have led to a decrease in stocks of both kinds of halibut across seas in the Russian Far East, data at the Russian Research Institute of Fisheries and Oceanography (VNIRO) suggests. The main factors, according to the data, are an absence of high-yielding halibut generations and changes in the oceans’ conditions due to climate change.
As a species, halibut requires careful monitoring, as it matures slower than many fish – a halibut typically doesn’t become reproductive until seven years old, but it can be as much as 10 to 17 years in some cases.
The reduction in halibut stocks has caused a proportionate reduction in the TAC out of caution. Preliminary figures for the species’ TAC for 2022 are 25 to 30 percent lower than for 2021 – signs the fishery could be in trouble.
The TAC for halibut has been declining over the last three years, Nikolay Antonov, head of the sea and fresh-water fish department at VNIRO, told Fishnews media agency.
Antonov said the first alarm bells rang in 2019, when in a few fishery zones in the northern part of the Sea of Okhotsk recorded significant overfishing, forcing VNIRO ask for a temporary closure of these areas to fishing.
The lower stocks have carried through to the amount of fish caught. In the Sea of Okhotsk, catch averaged 2 to 2.5 metric tons (MT) of black halibut per fishing day per ship two years ago, but that average fell to 1.5 to 1.7 MT in 2021. In the Bering Sea, many companies decided to quit fishing Pacific halibut and focus on cod, which has seen larger numbers recently, with halibut only caught as bycatch.
Primorye Fisheries Association President Georgiy Martynov said at a session of the Far Eastern Scientific Production Council earlier this year the decline in Russia's halibut stocks is alarming. In 2019 and 2020, companies in his association only caught 59 percent of the TAC set for halibut. In 2021, he said, the situation has been the same.
Martynov said lower catches have been compounded by killer whales that follow fishing vessels and eat the catch before it can be landed. VNIRO agreed killer whales can eat a significant amount of a fishing vessel's catch, but said there is no easy solution to that problem.
VNIRO has proposed changes in how halibut are managed, with a draft document being circulated to separate regulation of black halibut and Pacific halibut. The two species had previously been regulated separately until 2018, when they were combined to create an overall TAC for both species – one of the reasons for overfishing in the Sea of Okhotsk in 2019, Antonov said.
VNIRO has also called for augmented monitoring of the species to collect more data. The agency hopes to cooperate with fishing companies to place scientific observers onboard commercial vessels, along with video cameras. VNIRO hopes to use artificial intelligence to process recorded video footage to better understand the fishery. VNIRO also plans to conduct research trawls three times annually in both fisheries.
VNIRO is also investigating four separate solutions to deter killer whales from eating halibut catches, including special gear to draw their attention away from ships that are actively fishing, and tools to frighten the orcas away.
Photo courtesy of Vvicca1/Shutterstock