Fish communities consolidate their move north

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– Så mange som 25 nye arter kan komme inn i Barentshavet på grunn av klimaendringene., sier programleder Maria Fossheim.

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Photo: Erlend A. Lorentzen / Institute of Marine Research

Fish communities from southern Norway have consolidated their significant move north. The Barents Sea may become home to as many as 25 new species as a result of climate change.

Working with colleagues from institutions including UiT The Arctic University of Norway, the Institute of Marine Research’s Programme Director for the Barents Sea and Arctic Ocean Maria Fossheim has caused a stir with an article in Nature about how fish communities consisting of species such as cod and haddock are gradually moving north. The main explanation for this is the rapid climate change taking place in the Barents Sea. Warmer waters are making it habitable and providing plenty of food for species that normally prefer to stay further south.

A new normal

The study shows that there were significant changes in the distribution of these fish communities between 2004 and 2012. Over that period, they moved north more quickly than the IPCC had forecast in its various scenarios.

“Now we have processed data right up to 2017, and we can see that the fish communities appear to be stabilising at a new normal level. They have consolidated their move, and the northern Barents Sea is now more like the southern Barents Sea used to be. That is in line with expectations”, explains Maria Fossheim.

New species arrive, others are squeezed out

Based on projections and climate models, scientists can also predict what is likely to happen over the coming decades. As many as 25 new species may establish themselves in the Barents Sea by 2050 – depending on exactly how accurate the climate models are.

“Climate change means that the mix of species in the Barents Sea is changing. New species arrive, and others are squeezed out to the periphery. It’s difficult to predict which species will become common in the Barents Sea by 2050, but Arctic cod is an example of a species that will probably be squeezed out and have to find new habitats in the Arctic Ocean”, says Maria Fossheim.

Impact on fisheries

Climate change affects which species, and how much of them, can be harvested. Maria Fossheim finds that fishers are very keen to learn more about what the future holds for Norwegian fisheries.

“Globally, climate change is having a negative impact on fisheries, but here in Norway we will probably benefit up until 2050. We can’t say exactly how the mix of species and catch volumes will change, as there are too many factors that play in, including physical conditions and the biological interaction between species.”

Read the Nature article here:

Recent warming leads to a rapid borealization of fish communities in the Arctic

Fossheim, M., Primicerio, R., Johannesen, E., Ingvaldsen, R. B., Aschan, M. M., & Dolgov, A. V. (2015). Recent warming leads to a rapid borealization of fish communities in the Arctic. Nature Climate Change5(7), 673. LENKE: https://doi.org/10.1038/nclimate2647