In a recent study published in Nature Communications, researchers from the Basque technology centre AZTI, have shed light on the profound effects of ocean warming on marine biodiversity, as species struggle to adapt to different temperature conditions.

The Atlantic Ocean has been witnessing a surge in the presence of warmer-water species. Conversely, the Mediterranean and the Baltic Sea, experiencing accelerated warming, have seen a sharp decline in cold-water organisms. These shifts, termed tropicalization and deborealization, respectively, signal an unprecedented redistribution of marine ecosystems with far-reaching economic and social implications.

According to the findings, the rise in ocean temperatures has facilitated the dispersal and colonization of species, leading to the influx of warm-water organisms into new territories. A notable example is the fact that the eastern Mediterranean has witnessed an influx of Indo-Pacific species through the Suez Canal, sparking competition with native species and altering marine food webs. However, in semi-enclosed seas like the Mediterranean and Baltic, physical barriers impede the migration of cold-water species to more suitable habitats, exacerbating their vulnerability to warming waters. This has resulted in a decline of ecologically and commercially vital species such as the European sardine in the Mediterranean and cod in the Baltic Sea.

Moreover, the impacts of rising sea temperatures extend beyond fish populations to include coralligenous organisms and zooplankton, affecting biodiversity and habitat structure. These changes have repercussions on ecosystem services and marine resources, posing significant challenges for sustainable management.

In response, experts emphasise the urgency of science-based management strategies to mitigate the effects of ocean warming. This includes adjusting catch quotas and fishing efforts to reflect changing population abundances and implementing conservation measures to safeguard vulnerable species and ecosystems. As Europe’s marine environments continue to undergo rapid transformations, proactive measures guided by scientific research will be essential to ensure the resilience and sustainability of marine ecosystems in the face of climate change.

Source:
https://www.azti.es/en/impact-global-warming-on-european-marine-biodiversity/
https://www.nature.com/articles/s41467-024-46526-y