Jellyfish lead to increased mortality at Icelandic salmon farm

Icelandic salmon farmer Kaldvik has started harvesting from selected cages following a jellyfish incident at the company’s location in Reydarfjordur.

The producer stated in a stock exchange release that the 2025 generation in Reydarfjordur had been affected by jellyfish.

Since last Friday, the incident has led to additional mortality of around 0.3 percentage points in the 2025 generation, equivalent to approximately three out of 1,000 fish.

Culling fish

To reduce the risk of further losses, Kaldvik started culling fish from selected cages. The situation is now stable and is being closely monitored, according to the company.

Kaldvik's 2026 generation is in a different fjord and is not affected. The company said it will provide new information if necessary.

Kaldvik is Iceland's largest salmon farmer and has been hit by biological challenges in the past. In the first quarter, the entire harvest volume came from the 2024 generation, which had extensive problems with winter sores.

Only 30 per cent of the fish achieved superior quality. Low quality contributed to weaker price achievement and a significant operational deficit.

One-winter strategy

And in 2025, Kaldvik lost 900 tonnes of salmon after an algae outbreak.

Kaldvik has since moved away from the strategy of leaving the fish in the sea for two winters. The goal of the one-winter strategy is to reduce biological risk and improve fish health.