A new study shows that as water temperatures rise, fish foraging behaviour changes, and they choose more easily accessible foods and ignore those that are more nutritious but difficult to catch. This change can cause fish to not get enough energy, which in turn can affect the stability of the entire ecosystem.
Researchers at the German Center for Integrated Biodiversity Research (IDIV) and the Friedrich Schiller University Jena have found that in the Baltic Sea, fish choose more accessible foods when water temperatures rise, and this change in foraging behavior causes fish to miss out on opportunities to meet their long-term energy needs, potentially leading to more fish extinctions.
To study the response of fish foraging behavior to climate change, the researchers analyzed 10 years of data covering the stomach contents of six commercially important fish species with different foraging strategies. The results of the study showed that as the water temperature increased, the fish gradually shifted their attention from less prey to more prey. This change is more pronounced in warm water environments.
The researchers also used a mathematical food web model to simulate the impact of this change in foraging behavior on the ecosystem. The results suggest that this change could lead to more fish extinctions and have a knock-on effect on the entire ecosystem.
Although the results of this study are worrying, the researchers also note that the current findings are still based on theoretical models and need to be further tested and studied in a natural environment. In the future, researchers hope to be able to study different species to determine if they exhibit similar or different changes in foraging behavior. At the same time, the study is a reminder that the impacts of climate change on ecosystems may be more complex and far-reaching than we previously thought, and that we need to take more proactive measures to address the challenges posed by climate change.
Reference: Benoit Gauzens et al, Flexible Foraging Beh**iour increases predator vulnerability to climate change, Nature Climate Change (2024). doi: 10.1038/s41558-024-01946-y