Barbed wire jellyfish: Worst attack in decades sees 1.2 million salmon killed in single location

by
Editorial Staff

Salmar, the world’s second largest salmon farmer, reported the destruction of over one million salmon at one of its sites in Senja, following an attack by barbed wire jellyfish.

Shortly after the jellyfish were detected in the area, company employees observed dead fish and damage to the stock, prompting the decision to cull all the fish at the site for welfare reasons.

In a press release issued on Thursday, the company disclosed that the affected locality housed approximately 1.2 million salmon, each weighing an average of 0.3 kilos.

The operation to clear the site, assisted by personnel from an external emergency boat, was conducted around the clock and took 3-4 days to complete. Salmar noted that it had been two decades since they last experienced an attack of such severity

Despite the significant loss, Salmar has reported that this incident will not impact their guided harvest volume.

The attack on Salmar’s facility is not an isolated event; several other producers, including Grieg Seafood, Salaks, and Nordlaks, have also recently suffered losses due to Apolemia uvaria, sometime referred to as barbed wire jellyfish.

A siphonophore in the Apolemiidae family, Apolemia uvaria, known as string jellyfish or barbed wire jellyfish, is a colony of interconnected zooids. These animals can grow up to 3 meters long and 2-5 cm in diameter.

Historically, string jellyfish have been responsible for significant losses in the Norwegian aquaculture industry, with major incidents recorded in 1997 and 2001 resulting in the deaths of hundreds of tons of salmon.

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