Fish-feed industry turns to krill, with unknown effects on the Antarctic ecosystem

The Antarctic krill fishing industry has been growing in the past two decades which is an alternative to wild fish in fish feeds, amid the depletion of many wild fish stocks. Recently, demand for krill has spiked: Production increased from 104,000 metric tons in 2001 to a modern high of 451,000 metric tons in 2020, and is poised to continue rising.
The Norwegian company Aker BioMarine published several studies saying that, as an aquaculture-feed ingredient, krill can enhance growth and improve health, stress tolerance and fillet quality, mostly in farmed trout and salmon, but also for other marine fish and shrimp.
Aquaculture is behind a growing demand for krill, as the industry franticly searching for alternative protein sources to fishmeal and fish oil from wild fish to feed carnivorous fish and shrimp amid the depletion of many wild fish stocks. Yet the expansion of the krill fishery has raised concerns about its own sustainability.
How sustainable is krill?
Krill support the marine food chain around Antarctica, as they feed on phytoplankton and transfer energy and organic matter to predator species like fish, birds, seals and whales. Fishing industry representatives express confidence that krill are so abundant that catches can increase responsibly. However, outside scientists say both the krill and the predators that rely on them are already showing signs of stress from the fishery as well as from rapidly changing conditions due to climate change.
Krill “are consumed by all these different animals in the Antarctic, from whales, to seals, to fish, to penguins, to flying seabirds,” says Nicole Bransome, an officer with the Pew Charitable Trusts, a Washington, D.C.-based NGO that campaigns for the protection of Antarctic krill. “Everybody down there is relying on krill.”
According to Bransome, by eating phytoplankton, krill also play a fundamental role in the ocean’s ability to absorb carbon from the atmosphere. “The krill are actually like a conveyor belt, they’re bringing carbon from the atmosphere down to the depths,” she says.
The Antarctic krill fishery is managed by the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), a part of the Antarctic Treaty System, the international agreement for the management and protection of the continent since 1961.
Today, 12 krill fishing vessels operate in Antarctica, belonging to seven companies. Since 1991, the CCAMLR has allowed the fishery to catch up to 620,000 metric tons per year. “With that small amount the fishery is very sustainable compared with the total biomass available,” says Javier Arata, ARK’s executive officer.
The catch limit represents about 1% of the estimated biomass of Antarctic krill in the area where the fishery operates, around 62 million metric tons. So far, the fishery has never reached the overall catch limit. But during the past two decades, krill catches have been increasing, reaching 451,000 metric tons in 2020. And every year the catch does reach a more specific quota for the Antarctic Peninsula, triggering the closure of the fishery in that particular area around mid-year.
In 2000 and 2019, ARK collected data for two CCAMLR surveys to assess the krill biomass in the region — the only such surveys done to date. “The data was published in 2021 and found that the krill biomass hasn’t changed compared to 2000, it remains about 60 million [metric] tons, with a very similar distribution,” Arata says.
Lucas Krüger, who studies krill at INACH, says he disagrees with the industry position that the krill population is stable. “There is this inter-annual high variability of the krill biomass, but also there is evidence that this biomass is decreasing through time, meaning that even in the periods of higher biomass, it’s lower than it was in the past,” Krüger says.
A study published in September by researchers in Chile concluded that by 2100, the krill population biomass will undergo “a marked decline” that could range “from <50% to near extinction,” due mainly to the impact of climate change.
Russia & China investments
Russia has not been active in krill fishing since 2010. In February, Reuters reported that the country “announced plans to invest 45 billion roubles ($604 million) in the [krill] fishery, including building five high-tonnage trawlers.”
In 2010, the Chinese government launched a strategic plan to develop krill fishing in Antarctica, and since 2016 has subsidized the industry’s development. In 2022, a new vessel is slated to be added to the four already operating in Antarctica under the Chinese flag, and the country reportedly has two more vessels under construction.
According to Pål Skogrand, vice president of policy and impact for Aker BioMarine, the “krill [fishery] can never expand to a big extent, there will always be a very precautionary management of the volumes of krill.”
Yet Norway is also expanding its krill fishery. Aker BioMarine introduced a new fishing vessel in 2019 and a new support vessel in 2021, and announced growth targets of up to 60% of production in its latest corporate presentation. Rimfrost, another Norwegian krill company, is set to roll out a new fishing vessel in 2022.
Source: Mongabay