The International Year
of the Salmon Initiative

Bioregionalization of the subarctic Pacific based on phytoplankton phenology and composition

Project Contributors: Marta Konik

This study aimed to identify bioregions associated with distinct phytoplankton phenology and composition to comprehensively describe biological variability on the first trophic level across the subarctic Pacific, covering salmon’s feeding grounds during the marine life stage. Five bioregions were identified using the Self-Organized Mapping technique using 20+ years of satellite images. The bioregions in the open Pacific waters were dominated by green algae, haptophytes and pelagophytes, and were divided into the areas affected by the North Pacific Transition Zone and beyond. The other bioregions were defined around the Pacific basin margins where the diatom contribution was generally higher, with a particular distinction of waters surrounding the Kuril and the Aleutian Islands. Identifying bioregions is a critical first step towards understanding the large-scale spatial structure of phytoplankton communities that underpin the marine food web, with implications for zooplankton species and, subsequently, the entire marine fauna. The obtained bioregions allow for future evaluation of the processes controlling the physical and biological dynamics within each bioregion and provide information on stock-specific life history experience, useful for management decisions such as hatchery production levels.

You can read more here: https://doi.org/10.1016/j.pocean.2024.103315