A recent study published in Nature Climate Change has revealed that an “invisible forest” of phytoplankton, tiny drifting organisms, is thriving in the warming ocean. Phytoplankton do about half of the planet’s primary production through photosynthesis.
The University of Exeter-led research examined phytoplankton at the ocean surface and subsurface to understand how climate variability affects them. The findings show that these two communities are reacting differently to climate change.
While the total biomass of subsurface phytoplankton has increased in response to warming over the past decade, surface phytoplankton has seen a decrease in chlorophyll, making it less green, but its total biomass remains stable.
The study also suggests that the depth of the surface mixed-layer has shallowed as the ocean rapidly warmed in the last decade. This is based on 33 years of data from the Bermuda Atlantic Time-series Study (BATS) in the Sargasso Sea.
Phytoplankton are the foundation of the marine food web and play a key role in removing carbon dioxide from the atmosphere. The study’s authors emphasize that understanding these trends is crucial because changes at the base of the food web can have cascading effects on marine life.
Dr. Johannes Viljoen, one of the co-authors, notes that continued monitoring of deep-lying phytoplankton will help scientists better understand ongoing changes in the ocean that might otherwise go unnoticed. The study highlights the limitations of satellite observations and underscores the urgent need for improved global monitoring of phytoplankton below what satellites can see.
Source: https://phys.org/news/2024-09-invisible-forest-phytoplankton-ocean.html