Climate change and jellyfish blooms threaten Atlantic salmon health

A joint study by Spain’s Instituto de Acuicultura Torre de la Sal (IATS-CSIC) and Norway’s Nofima research institute has identified a “perfect storm” of environmental factors threatening Atlantic salmon health. The research, published in Frontiers in Marine Science, indicates that rising water temperatures and declining oxygen levels are primary drivers in altering the beneficial microbiota and immune responses in salmon gills.

The study highlights that jellyfish blooms, specifically the species Aurelia aurita, act as a catalyst that exacerbates this physiological deterioration. In open-sea aquaculture settings, jellyfish frequently collide with or pass through cage nets, causing mechanical injuries to the fishes' respiratory systems. This combination of thermal stress, hypoxia, and physical damage poses a significant risk to the global salmon industry, which saw production exceed 2.8 million tons in 2023.