Already at the beginning of the year, IntraFish had established during a field visit, the presence of jellyfish. But these weren't of any significant size and they weren't present in great quantities.

However, lately these have become a threat for salmon farmers.

Several sources have commented to IntraFish that some fish farms have already been affected, information that now is confirmed by Hans Steffens, the Aquaculture Liquidator Engineer for Juan Pablo Valdivieso and Associates, in charge of attending to close to 60% of the salmon companies insured by a selection of insurance companies.

Large number of mortalities According to information obtained by IntraFish, there are losses of about 120,000 fish on a farm located in the Quemchi area. Steffens further confirmed that about 45,000 fish had died on another farm in the same area, also because of jellyfish attacks.

"The jellyfish are in every way a threat for salmon farmers. In fact, there are already farms that have suffered losses because of them. The only measure that can be taken is to put a kind of curtain around the sea pen. The problem with this is that the sea pen must be sufficiently aerated because if not, the water is kept from circulating," Steffens told IntraFish.

He added that several companies have already adopted this defence measure.

"The jellyfish cause damage because they produce a poison that paralyses the fish. And these jellyfish are quite big. We have measured jellyfish up to 1.1 metres across, with tentacles reaching 3 to 4 metres long," Steffens added.

Jellyfish and El Niño – an omen? Some people who have been working on fish farms for several years have told IntraFish that, to them, the jellyfish are an omen of the arrival of El Niño. In past years, jellyfish attacks have been followed by rains and storms typical of the weather phenomenon.

Jellyfish attacks in Chiloé cause more salmon deaths