Two environmental groups are calling for krill fishing to be outlawed, saying super trawlers are endangering pods of whales in the Southern Ocean.
The Bob Brown Foundation and Sea Shepherd Global have travelled to waters off the Antarctic Peninsula, tracking super trawlers fishing for krill.
The groups filmed the trawlers operating near some whales, and said so-called "fish factory" super trawlers were "ploughing right through" large pods.
Four vessels were filmed by the groups: the Shen Lan and Long Fa, from China, the Antarctic Endeavour, from Chile, and the Sejong, from South Korea.
The Bob Brown Foundation said that upon it and Sea Shepherd arriving at the South Orkney islands, both Chinese vessels "immediately recovered their fishing gear and began to run from the fishing grounds".
"Both the Antarctic Endeavour and the Sejong were seen trawling through a group of over 100 fin whales," the foundation said.
"Krill is the foundation of the Antarctic ecosystem," Bob Brown Foundation campaigner Alistair Allan said.
"They deserve total protection, not super trawlers hoovering them out of the ocean."
Krill is fished for products including fish farm feed and health supplements.
Norway, China and Korea are among the countries using super trawlers in the krill fishery.
Sea Shepherd Global and the Bob Brown Foundation are now calling for Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) to outlaw krill fishing.
"The krill fishery takes out the base of the entire Antarctic food chain," said Alex Cornelissen, chief executive of Sea Shepherd Global.
"This is a fishery that should not be allowed to operate in this pristine environment, and we will be working towards that, whether it's through the law or through the markets."
Krill fishing rules
Antarctic krill are allowed to be fished in certain areas of the Southern Ocean, based on rules developed by CCAMLR.
CCAMLR sets an allowable catch limit, aiming to reserve more than 75 per cent of the krill biomass for predators
In 2021, 371,526 tonnes of krill were caught, down from the 450,781 tonnes caught in 2020.
The vessels recorded by the Bob Brown Foundation and Sea Shepherd were fishing in an area near the South Orkney Islands which is a designated Antarctic krill fishery under CCAMLR rules.
A scientific study recently published in the journal Ecology also documented four commercial fishing vessels trawling for krill among a "supergroup" of fin whales in the same area in January 2022.
The authors warned of "serious concerns about krill harvesting in the Southern Ocean and whether existing environmental policies are sufficient to ensure the long-term health of these whales".
Author Matthew Savoca, from the Hopkins Marine Station of Stanford University, said there were concerns about the potential for super trawlers to hit whales or for whales to be tangled in the fishing gear in the water and become bycatch.
But he said his bigger concern was that super trawlers and whales were in direct competition for krill.
"So these Antarctic krill are the only thing that these whales eat," he said.
"And not only are these whales interested in Antarctic krill, but they're interested in these really dense and large swarms of Antarctic krill.
"So individual krill is worthless to these whales — the thing that they're after are these humungous clouds of krill, these underwater clouds, giant swarms of krill, which is also what the boats are after."
He said there was the potential for that competition to become problematic.
There is evidence of climate change affecting krill numbers in the Southern Ocean, and Dr Savoca said whaling in the 20th century also likely degraded krill habitat.
He said there was no current evidence that the krill fishery was directly impacting krill populations.
"But there is a good amount of evidence to suggest that the krill population is threatened by a variety of stressors," he said.
"And so we need to basically carefully monitor the effects of the fishery on krill and krill-dependent predators like whales."
Dr Savoca said there could be more active management of the krill fishery, "whereas right now, there's not very much sort of done in terms of trying to avoid whales or trying to not harm these specific animals".
The Minister for the Environment and Water, Tanya Plibersek, said krill fishing was one of the reasons the federal government was pushing to establish an east Antarctic marine protected area.
"The park would include a large zone where krill fishing was not permitted," she said.
"The government supports more restrictions on krill fishing in the Southern Ocean."
CCAMLR has recorded whale deaths
The Association of Responsible Krill Harvesting Companies said the vessels near the Antarctic Peninsula were licensed, operating in accordance with CCAMLR conservation measures, and all had scientific observers onboard.
"The Antarctic krill fishery is recognised globally as one of the best managed in the world," it said.
In a statement, CCAMLR said it had effectively managed the krill fishery using the ecosystem and precautionary approaches since the 1980s.
"Smaller area limits are set to further reduce potential interaction between predators and the fishery, scientific observers are present on all krill vessels, and other environmental and reporting requirements apply to the fishery, including the requirement to use devices to avoid accidental mortality to seabirds, seals and whales," the statement said.
"CCAMLR annually reviews and publishes in its reports assessments of compliance against its conservation measures, and the Scientific Committee's working groups monitor the impact of the fishery on the ecosystem and any direct impacts on birds, seals and whales."
The conservation measure that applies to the krill fishery requires all vessels to use marine mammal exclusion devices on trawls which stop seals and whales from entering the net.
CCAMLR has observers on all krill vessels.
"Some incidental mortality of humpback whales has been recorded, but no incidental mortality of fin whales," it said.
CCAMLR said it was aware of concerns from non-government organisations, and was actively developing a "new harmonised approach to krill fishery and protected area management in the Antarctic Peninsula and South Orkney Islands".
"The Commission will consider these issues again at its meeting in October 2023," it said.
