Ripple effect expected all along the ocean food web
FRISCO — Given the complex dynamics of ocean circulation, it’s tough to predict how global warming will play out, but a European research project has been able estimate that phytoplankton biomass could be reduced by 6 percent, while zooplankton biomass may decline by as much as 11 percent.
Those changes could have big impacts on important fish species, researchers said after publishing their findings in Global Change Biology.
Warming ocean temperatures will alter circulation patterns and water column stratification, which affects the transport and availability of nutrients for marine plankton growth. This process will take place mainly in tropical oceans, which cover 47 percent of the global ocean surface. Globally, sea surface temperature is expected to increase 2 degrees Celsius by 2080-2100.
“Climate regulation will also be affected negatively by the primary and secondary production decrease globally … because, as there will be less phytoplankton, absorption of CO2 from the atmosphere by the oceans will be lower, as plankton is responsible for half of the planet’s photosynthetic activity. This in turn will reduce the ocean’s capacity to regulate the climate,” said lead author and primary researcher Guillem Chust.
But there will be regional differences. In the seas in Central and Southern Europe (North Sea and temperate Northeast Atlantic), higher thermal stratification of the ocean water layers and, consequently, a lower presence of nutrients for phytoplankton to grow, will reduce primary production; and in the Baltic, Barents and Black Sea phytoplankton production is expected to increase.
The MEECE project is part of the EU’s Seventh Framework Programme and is coordinated by the Plymouth Marine Laboratory (UK), with 22 European partners. MEECE’s scientific challenge involves understanding how marine ecosystems work and how they are affected by climate change, ocean acidification and human activities. Within this initiative, AztiTecnalia observes the ecosystem, studying the processes and developing models to simulate future changes, while proposing measures allowing for the anticipation and minimisation of such changes. All the information on the project can be found at http://www.meeceatlas.eu/.