July 29, 2025 — An international team of fisheries scientists studying data gathered during the oceanic winter of 2022 in the Northeast Pacific Ocean has identified distinct ocean biomes impacting the marine survival of Pacific salmon species.
Their report, based on an ecosystem-wide environmental DNA (eDNA) survey across 2.2 million square kilometers of open ocean habitat, found that salmon exhibited species-specific distribution across the Northeast Pacific. These distributions were associated with swirling ocean currents known as mesoscale anticyclonic eddies—currents that rotate clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere, characterized by a high-pressure center. These eddies play a significant role in ocean circulation by transporting heat, salt, and other properties, and by influencing biological activity.
Ocean biomes are aquatic ecosystems characterized by saltwater and include the Pacific Ocean, the largest and deepest of the world’s oceans, known for its diverse marine life and volcanic activity.
The voyages, part of the International Year of the Salmon initiative, began in 2017 and concluded in 2022, though analysis of the collected data continues. These voyages were a collaborative effort involving the North Pacific Anadromous Fish Commission (based in Vancouver, Canada), the North Atlantic Salmon Conservation Organization (based in Edinburgh, Scotland), and various other organizations across multiple countries. Their goal was to raise awareness about the importance of salmon conservation.
This latest research report was published on July 8 in the ICES (International Council for the Exploration of the Sea) Journal of Marine Science.
Researchers concluded that salmon displayed species-specific positive associations with potential prey species and competitors. However, some salmon were negatively associated with specific cnidarians and harmful algae. Cnidaria are a group of aquatic invertebrates found in both freshwater and marine environments, ranging from jellyfish, sea anemones, and corals to some of the smallest marine parasites.