Affects marine ecosystems ... a dramatic decrease in marine plankton over the past six decades

Laila Ali

A new research published in the "Global Change Biological" magazine showed that the plankton community in the waters of the United Kingdom - the microalgae and animals that support the entire marine food network - has witnessed comprehensive changes in the past six decades.

Plankton and human influences
With the cooperation of leading sailors from all over the UK, led by the University of Plymouth, the research for the first time combines the results of British surveys such as "continuous plankton registrar" (CPR) and long-term time series data data.

Hence, maps containing these observations were drawn against the recorded changes in sea surface temperature to show the effect of the changing climate on these highly sensitive marine societies.

The authors of the study say that their findings provide further evidence that increasing direct human pressure on the marine environment - along with climate-driven changes - disturbs marine ecosystems worldwide.

They also say that it is important to help understand the vast changes taking place in the world of the seas, given that any transformations in plankton societies have negative consequences for the marine ecosystem and the services it provides.

Because plankton is the primary base of the marine food web, changes in plankton are likely to lead to changes in commercial fish stocks and sea birds, and even the ocean's ability to provide the oxygen we breathe.

Long-term changes
Functional group analyzes of planktones showed profound long-term changes, which were intertwined across broad geographical regions just around the British coast.

For example, the average abundance of zooplankton for my decade 1998-2017 - a type of zooplankton that includes lobsters and crabs, and that spends its adult life on the seabed - was 2.3 times that of 1958-1967 when comparing samples of the "continuous planktonic registrar" In the North Sea, at a time when sea surface temperatures have increased.

This contrasts with a general decrease in plankton that spends its entire life in the water column, while a decrease in the number of other marine species has been observed by about 75%.

"Plankton is the bedrock of the entire marine food network, but our work shows that climate change has caused plankton to undergo a major reorganization of water in the UK," says Dr. Macqueters-Golub, a pioneer in the UK's marine habitat policy.

"These changes in plankton will cause changes to the entire marine ecosystem, and have consequences for marine biodiversity, climate change (carbon recycling) and food webs, including commercial fisheries," he says.

Long-term data
"The changes in plankton communities not only affect many levels of marine ecosystems, but also the people who depend on them, particularly through the effects on fish stocks," says Dr. Claire Austell of the Marine Biology Survey (CPR) of the Marine Society. Commercial. "

She adds, "This research is a great example of how to collect different sets of data to investigate long-term changes in important planktonic groups in the context of increasing temperatures. This type of collaborative studies is important to guide policies and assessments of our changing environment."

"In this paper, we attempted to convert decades of guesswork into evidence, since it was long believed that warming seas affected plankton," added Professor Paul Tate - co-author of the study from the Scottish Society of Marine Sciences (SAMS).

"By bringing together major long-term data sets from all over the UK for the first time, we have discovered that the picture is complex, so we need to build on this success in joint cooperation, by increasing support for the continuing plankton regiment and marine plankton observatories."