The marine heatwave hitting northern Europe is particularly affecting the offshore coasts of the archipelago, with potential consequences for the fisheries sector.
The sea is sweating off the UK coast. The invisible heatwave crossing the Atlantic reached the British Isles last week and is at its strongest there. In the water, the temperature regulator rose 5°C above the normal for the season. A colossal number: it takes much more energy to heat water than air, and the temperature of the oceans varies by only about ten degrees from season to season. Scientists are already assuming that the current heat wave will lead to the death of many marine animals. For a number of years, Professor Stuart Cunningham, an oceanographer and a member of the Scottish Association for Marine Science, has been observing changing marine life, particularly among crustaceans: “Here in Scotland, on the west coast, the mussels are going from a cold water type to a more so.” Mediterranean type.”
In the short term, many fish are also likely to leave English and Scottish waters to seek refuge closer to the poles and find a mercury better suited to their lifestyle. “Fish are very sensitive to the temperature ranges in which they live. And because they’re mobile, they can move around very quickly,” explains Stuart Cunningham. So agrees Jean-Pierre Gattuso, director of research at CNRS and co-editor of an IPCC report for which “the waters of Norway and Iceland are getting richer in fish”. An additional problem for the UK fisheries sector, which is already in trouble after Brexit: there are fewer fishermen every year and exports have been falling since 2018.
“Mackerel War”
As the archipelago country whose sea has been hardest hit by the ocean heatwave, Scotland is the biggest player in UK fisheries. One of the sector’s most important products is farmed there in certain coastal farms: salmon. Back in 2019, Professor Mike T. Burrows warned in The Herald that sudden ocean heatwaves could be “bad things” for salmon farms. “Fishermen will no longer catch the same fish, and those who rely on a particular shellfish species will be affected,” added the researcher, who stated at the time that Scotland had yet to experience a real sea heatwave. According to Stuart Cunningham, mackerel is one of the fish most likely to be affected by these heat waves. However, with a value of more than £220 million in 2021, it is also by far the most fished species in UK waters. Enough to reignite the ‘mackerel war’, a decade-long dispute that has pitted the UK against more northerly countries like Iceland and the Faroe Islands, which benefit from fish migration.