Cutting the food chain? The controversial plan to turn zooplankton into fish oil

theguardian.com:

A few times a day, off the Faroe Islands’ coast, the crew of the Jákup Sverri marine survey ship test the water, measuring its salinity, temperature and oxygen at different sea depths. But they also look for something else.

Durita Sørensen, a laboratory technician, holds up the contents of a special net to demonstrate. If the water is greenish, it contains a lot of phytoplankton, the plants at the base of the oceanic food chain. But if it is red or brown, as in Sørensen’s net, the haul is one rung higher up the ladder: zooplankton. “This is calanus, or Calanus finmarchicus,” she says, indicating the tiny red creatures. “This is what they are interested in making fish oil [from] as a food supplement for humans.”

Zooplankton is a crucial part of the Atlantic Ocean ecosystem. And calanus – known as Reyðæti in Faroese or “red plankton” – is one of the most important and populous varieties. In 2020, the Faroese fisheries ministry gave five companies the right to fish for up to 25,000 tonnes of it each.

There is no factory yet on the Faroe Islands for processing the tiny red creatures into fish oil, but entrepreneurs are hoping it will soon become big business, supplying not only the apparently insatiable demand for omega-3 health supplements across the western world, but potentially for use in the even vaster fish-farming industry.

Zooplankton fishing is already happening in Norway, where a company called Zooca, which has been harvesting red plankton for some years, received a commercial quota in 2020. The Norwegian Institute of Marine Research says the harvest is well within sustainable limits.

But many in the fishing industry are unhappy about the idea of sucking up zooplankton. Red plankton is the main food of many hugely