MIAMI >> Two humpback whales were found dead and another seriously injured this year in huge nets used to collect krill for fishmeal and omega-3 pills near Antarctica, The Associated Press has learned.

The whale deaths, which have not been previously reported, were discussed during recent negotiations between the U.S., China, Russia and two dozen other countries in which officials failed to make progress on long-debated conservation goals and lifted some fishing limits in the Southern Ocean that have been in place since 2009.

Taken together, the whale deaths and rollback of the catch limits represent a setback for the remote krill fishery, which has boomed in recent years and is set to expand even further following the acquisition of its biggest harvester, Norway’s Aker BioMarine, by a deep-pocketed American private equity firm.

AP journalists last year spent more than two weeks in the frigid waters around Antarctica aboard a conservation vessel operated by Sea Shepherd Global to take a rare, up-close look at the world’s southernmost fishery. As part of that investigation, the AP followed the tiny crustacean on its journey from the fragile ecosystem, where it is the main nourishment for whales, to salmon farms in Europe, Canada and Australia, pet food manufacturers in China and a former ice cream factory in Houston that produces 80% of the world’s nutrient-rich krill oil.

Delegates to the annual meeting in Australia of the Commission for the Conservation of Antarctic Marine Living Resources, or CCAMLR, shared with the AP unpublished reports of the whale deaths on the condition of anonymity because the talks, which ended last week, are not open to the public. Officials at CCAMLR, which was established in 1982 to protect the international waters near Antarctica, didn’t comment.

Under a conservation agreement developed almost two decades ago, the krill catch has soared: from 104,728 metric tons in 2007 to 424,203 metric tons in 2023 as larger, more sophisticated vessels have joined the chase. So far this year, the catch has jumped to 498,000 metric tons — the highest on record, according to the unpublished reports.

Although fishing is still below a previously agreed limit and barely 1% of the estimated biomass of 63 million metric tons of krill found in the main Antarctic fishing grounds, direct competition between marine mammals has resulted in whale deaths before.

But following the first ever recorded entanglements of four humpback whales in 2021 and 2022, Aker BioMarine redesigned its fishing nets, which regularly vacuum up to 500 metric tons of krill per day — the equivalent daily diet for about 150 humpback whales. First, it added a rope barrier to repel large mammals and then, last fall, it developed a second barrier to close a still sizable gap that can threaten whales swimming vertically.

The new net had not yet been installed when a juvenile humpback was observed dead Jan. 27 on the Antarctic Endurance, the company’s most advanced supertrawler, according to a report presented by Norwegian negotiators at the CCAMLR meeting.

The reasons behind the second death in May involving another Aker BioMarine ship remain unclear. But two days earlier the ship reported difficulty maneuvering its net and blubber was recovered on the ship’s conveyor belt, suggesting the dead whale had been trapped by the net for some time, the report said.

A third humpback was hauled alive in late January on a Chilean-flagged vessel, the Antarctic Endeavor, using traditional trawling gear. After the ship’s crew struggled for 40 minutes to cut the net tightly wrapped around the 15-meter-long (15-yard-long) male, the whale, with blood on its tail, was dumped back into the ocean.

“Upon release it was lethargic and had some injuries from rubbing with the net,” according to a report by Chile’s delegation to the CCAMLR talks that included graphic images of the capture. Although the whale was observed swimming, the capture was considered a mortality event by CCAMLR scientists because the released whale’s injuries were likely to prove fatal.

Attempts to contact the trawler’s owner, Pesca Chile SA, were unsuccessful.

A minke whale was also found dead after entangling itself in a buoy line belonging to a South Korean vessel targeting Patagonian toothfish, which is also managed by CCAMLR. It was the first ever whale death recorded in the fishery.

Pressure on krill stocks is building as a result of surging demand for omega-3 pills taken as dietary supplements, advances in fishing and rising ocean temperatures due to climate change.