Plankton form the base of the marine food web, are integral to ecosystem functioning, and respond quickly to changes in their environment. Climate warming, ocean acidification, and human activities leading to the spread of invasive species are causing distributional shifts in plankton communities which directly affect ecosystem services such as carbon cycling, oxygen generation, and food production. Change in plankton distribution, therefore, is a sensitive and important indicator of marine climate change throughout the world ocean. Spatially-extensive, multi-decadal plankton datasets, such as the Continuous Plankton Recorder survey, have revealed that the base of the marine food web is changing, with spatial shifts identified in phytoplankton productivity, phytoplankton composition, and zooplankton composition. Northeast Atlantic zooplankton communities, for example, are becoming ‘tropicalised’ with warm water taxa increasing in abundance and cold water taxa shifting poleward. Similarly, temperate marine plankton communities are becoming characterised by large-sized zooplankton species, which have replaced smaller species during recent decades, suggesting an altered trophic functioning in these systems. These shifts in plankton distribution are linked to change in higher trophic levels, such as commercially important fish species, as well as to changes in marine ecosystem functioning and productivity, including carbon and nutrient cycling. Commercial fisheries, conservation efforts, and international policy commitments therefore must consider and adapt to plankton on the move.
Download poster: Plankton on the move: implications for global biodiversity goals