23 Oct The increase of temperatures caused by climate change will collapse the populations of some species and favor the invaders
Biological invasion of certain species is one of the most serious problems affecting biodiversity on a global scale. Climate change, caused by our society industrialization is changing the biosphere structure and function and manifests itself in multiple ways.
Besides the atmosphere and oceans warming, extreme events such as floods, droughts and heat waves are becoming more frequent and intense. The seasons are ahead and behind and the climatic variability of the average conditions continues to grow, both locally and globally.
If sea temperatures and invasive species continue to increase, current efforts to reduce fishing may not be enough to recover the fishery resources of native species such as hake.
Xavier Corrales, of the CSIC Institute of Marine Sciences, has just published a study concerning this problem in Scientific Reports.
According to this study, scientists have evaluated reducing fishing pressure effects in different possible future scenarios. In order to achieve this, they have used a calibrated ecological model based on the Eastern Mediterranean, and have evaluated their response to three variables:
- Temperature increase
- Changes in fishing pressure
- Increase in invasive species.
First, they have evaluated the ecosystem response to each of these three variables, independently, and then they have combined them to simulate a total of 11 future scenarios.
What happens in this future scenarios?
When the fishing effort is reduced with the current temperature, the model predicts the recovery of some highly exploited species. However as soon as the future temperature increases, some native species collapse, while invasive species expand.
The results show that in the future all the benefits of reducing fishing can be overshadowed by the expected temperature increases. Taking into account the intermediate hypothesis of climate change (not very pessimistic but not very optimistic).
Xavier Corrales explain “Our study raises awareness in sustainability limits and how current efforts may be insufficient to mitigate the effects of climate change and invasive species in the future”
The problem according to Xavier Corrales “An ecosystem, when more stressed (by fishing, invasive species and temperature), is more vulnerable and less resilient. “
Similar to the Red Sea
What the scientists have used is a model of the eastern Mediterranean since it is the area where some of these impacts are most accentuated. Xavier Corrales clarifies: “In the Eastern Mediterranean there are many species from the Red Sea that have come through the Suez Canal, there is a high impact of fishing, the environmental conditions are extreme and there is a greater increase in temperature than in the Western Mediterranean. “
Xavier Corrales thinks that, as a result, the rise in temperature facilitates the entry and expansion of invasive species and strongly impacts the populations and ecosystems of the entire Mediterranean.
Furthermore, Corrales explains “The Mediterranean is going through a meridionalization and tropicalization process both in the north and south respectively, because of the expansion to the north of thermophilic species and the introduction of invasive species (mostly of tropical origin). “
Several countries and universities have participated in this study Institute of Limnological and Oceanographic Research (Israel), the University of Tel Aviv ( Israel) and the University of Haifa (Israel), the scientific association Ecopath International Initiative (Spain), the Scottish Marine Institute (UK), the European Marine Board (Belgium).