This summer is shaping up to be one of the most worrying when it comes to the surface temperatures of the seas that wash the European coast, with July recording the highest levels since records began.
In a report released this Wednesday by the World Weather Attribution organization, climate change is driving unprecedented sea temperatures in Europe, with the region’s seas warming faster than the climate itself. And researchers warn that this extreme warming is having disastrous consequences for marine life in the region.
Several species are moving northward toward cooler waters, with negative impacts on fishing and aquaculture. In the United Kingdom there has been an exponential increase in octopus abundance, which raises concerns about the stability and functioning of marine ecosystems. There are also reports of changes in the food webs, with, for example, dolphins feeding on jellyfish due to the decline in abundance of their usual prey, such as horse mackerel.
Moreover, the authors of this study point out that high sea temperatures are causing mass mortality events of species vital for the building and maintenance of marine habitats, such as corals, sponges and macroalgae. “The loss of such fundamental species has an impact on the structure and functioning of the entire ecosystem,” they write.
That mass mortality will likewise have impacts at other levels along food webs, potentially affecting invertebrates, fish, birds and marine mammals.
As the seas become warmer, biodiversity undergoes profound changes, not only with the displacement of species to cooler waters, but also with the reconfiguration of the very composition of marine organism communities and with the replacement by species better adapted to higher temperatures.
But even those best-adapted species have limits, which may be surpassed as marine heatwaves become more frequent, longer-lasting and more intense. Therefore, the researchers say that “a rapid transition away from fossil fuels is essential to save crucial ecosystems, fisheries, food production and tourism on Europe’s coasts.”
In addition to ecological impacts, there are climatic ones, as the scientists signing this work explain that the increase in surface sea temperature can influence regional climate and drive extreme events such as torrential rainfalls. In Europe, elevated temperatures in the Mediterranean have been associated with intense precipitation events that caused the Valencia floods in 2024.
The team says that adaptation measures to the rising marine temperatures, and to their effects, such as reducing pressure on marine ecosystems, protecting habitats, improving early warning systems and changes in the management of fishing and aquaculture, can increase resilience and reduce vulnerability. However, they issue a warning: given the current state of things, they will not be able to “fully compensate for the ecological impacts of continued marine warming.”
