An international team led by the Forest Technology Centre of Catalonia has carried out the first large-scale study of the threats facing freshwater fish in the Mediterranean basin. Invasive species, along with over-exploitation of water resources, are the most important pressures, and those that expose fish to the greatest risk of extinction.
"The continental fish of the Mediterranean basin are one of the most threatened biological groups in the world", Miguel Clavero, lead author of the study and a researcher from the Landscape Ecology Group of the Forest Technology Centre of Catalonia, tells SINC.
The study, which has been published in the journal Diversity and Distributions, looks at the geographical distribution of the manmade factors (pressures) with a negative impact on biodiversity and their relationship to the degree of threat faced by endemic freshwater fish communities in the Mediterranean basin. The study combined information on the pressures affecting 232 fish species and their distribution range.
"The Iberian Peninsula is one of the areas in which invasive species have the greatest impact on native fish", explains Clavero. His team has studied the commonest pressures, such as pollution, water extraction, invasive species, reservoirs, agriculture and over-fishing.
By relating the distribution of these pressures with the degree of threat faced by the fish in each area, the researchers have shown that "fish communities are exposed to the greatest threat of extinction when the most significant pressures are the impact of invasive species and over-exploitation of water resources", the expert says.
Clavero says "these two pressures are the leading causes of biodiversity loss among continental fish in the Mediterranean region". The results bear out those of other studies on a smaller geographic scale carried out in various parts of the Mediterranean.
"We also have notorious examples in Spai
FECYT - Spanish Foundation for Science and Technology