Aerial view of a Blumar salmon farming facility.

 

Photo: Blumar.

Aquaculture

Harmful algal bloom in Chile triggers mass salmon mortality event

To date, approximately 3,800 metric tons (MT) of Atlantic and coho salmon have died as a result of the algae bloom, which was first reported on 2 January.

Louisa Gairn

Chile's salmon farming industry has started the new year 2024 with the unwelcome news of a harmful algal bloom causing mass mortality of farmed fish northeast of Isla Victoria, an island in the Chonos Archipelago of Chile.

Thus far, four salmon farmers have reported they are affected by the bloom, with five separate fish farming centers implicated, in Chile's Salmonid Concessions 22B, 22C and 23C.

Blumar and AquaChile were the first to report the microalgae on 2 January, according to Sernapesca, Chile's National Fisheries and Aquaculture Service. Since then, neighbouring operators Mowi and Multi X have also reported they have been affected.

Sernapesca says that approximately 3,800 metric tons of fish have been lost due to the bloom.

This figure has grown since 2 January 2024, when initial reports indicated 2,854 tons of Atlantic salmon and coho salmon had died.

The deadly microalgae in question is Pseudochatonella spp.

The companies in question have activated contingency plans to deal with the situation, and Sernapesca says it is monitoring their compliance as the companies work to remove the affected fish.

Harmful algal bloom continues, Sernapesca to monitor spread

Commenting on the situation, Sernapesca's acting regional director Juan Carlos Orellana said that the Sernapesca will continue to monitor the presence of harmful algae in the affected zone and surrounding areas, saying "the centers in these areas continue to report the presence of the microalga daily."

The news follows an earlier HAB event in Chile during November 2023, where 1,500 tonnes of fish were lost due to the microalgae Thalassiosira pseudonana.

The previous algal bloom affected 18 salmon farming facilities in the Reloncaví Estuary, a fjord off Reloncaví Sound, located in the Los Lagos region of Chile.