The UK’s plankton population – microscopic algae and animals which support the entire marine food web – has undergone sweeping changes in the past six decades, according to new research published in Global Change Biology.
Involving leading marine scientists from across the UK, led by the University of Plymouth, the research for the first time combines the findings of UK offshore surveys such as the Continuous Plankton Recorder (CPR) and UK inshore long-term time-series.
It then maps those observations against recorded changes in sea surface temperature, to demonstrate the effect of our changing climate on these highly sensitive marine communities.
The study’s authors say their findings provide further evidence that increasing direct human pressures on the marine environment – coupled with climate-driven changes – are perturbing marine ecosystems globally.
They also say it is crucial to helping understand broader changes across UK waters, since any shifts in plankton communities have the potential for negative consequences for the marine ecosystem and the services it provides.
Since plankton are the very base of the marine food web, changes in the plankton are likely to result in changes to commercial fish stocks, sea birds, and even the ocean’s ability to provide the oxygen we breathe.
The analyses of plankton functional groups showed profound long-term changes, which were coherent across large geographical areas right around the UK coastline.
For example, the 1998-2017 decadal average abundance of meroplankton, a group of animal plankton, which includes lobsters and crabs and which spend their adult lives on the seafloor, was 2.3 times that for 1958-1967 when comparing CPR samples in the North Sea, at a time of increasing sea surface temperatures.
This contrasted with a general decrease in plankton which spend their whole lives in the water column, while other offshore species noticed population decreases of around 75%.
The study was led by former postdoctoral researcher Dr Jacob Bedford and Dr Abigail McQuatters-Gollop, from the University of Plymouth’s Marine Conservation Research Group. It also involved scientists from The Marine Biological Association, Plymouth Marine Laboratory, The Environment Agency, Marine Scotland Science, Centre for Environment Fisheries and Aquaculture Science (Cefas), Agri-Food & Biosciences Institute of Northern Ireland, and the Scottish Association for Marine Science.