Tista Karmakar
Rapid Decline In Plankton Population, Researchers Say Due To Ocean Warming
Scientists from the University of Oxford and Plymouth Marine Laboratory report a rapid decline in plankton populations across the world’s oceans, with serious implications for marine ecosystems and global carbon sequestration. The study analyzed 60 years of plankton survey data collected by research vessels and satellite observations.
The Plankton Crisis
Plankton forms the foundation of marine food webs, supporting everything from small fish to whales and seabirds. The study, published in Proceedings of the National Academy of Sciences, found that plankton biomass has declined by 20% since 1990 in the North Atlantic alone. Rising sea temperatures and ocean acidification are primary drivers, with warmer waters reducing nutrient mixing that phytoplankton depend on for growth.
Carbon Sequestration Impact
Marine phytoplankton produces at least 50% of Earth’s oxygen and absorbs approximately 25% of anthropogenic CO2 emissions through the biological pump. Researchers estimate that the observed decline could reduce the ocean’s carbon uptake capacity by 2-10% by 2050, according to the Intergovernmental Panel on Climate Change. This reduction could accelerate global warming by adding 0.3°C of additional warming this century.
Temperature Correlations
Data from the Argo float network shows a direct correlation between sea surface temperature increases and plankton abundance. Warmer waters hold less nutrient density, reducing the productivity of phytoplankton photosynthesis. The North Sea has warmed 2.5°C since 1980, faster than the global ocean average, resulting in a 15% decline in summer chlorophyll levels.
Food Web Consequences
Fish populations that depend on plankton, including cod, herring, and mackerel, have declined in parallel. The Food and Agriculture Organization reports that 34% of global fish stocks are overfished, compounding the plankton decline impact on marine food security. The California Current has seen a 40% reduction in krill abundance since 2014, affecting whale migration patterns.
Global Implications
The decline affects the livelihoods of 3 billion people who depend on fish as their primary protein source. UNESCO’s Intergovernmental Oceanographic Commission warns that continued ocean warming could trigger cascading ecosystem collapses by 2060 under high-emission scenarios, threatening global food security for billions.
Related environmental research: Sharks and rays overfishing crisis and Rare wildlife sightings.
