A study by Australian scientists, published in the journal Nature Climate Change, said the warming of sea-surface temperatures and the resulting increased acidity slowed fish growth rates and damaged coral reefs where they breed.
This could be especially serious for many commercial fish in the Mediterranean which do not move much, one author of the study said. Some of the most prized fish on the menus of prestigious European restaurants are faced with extinction because too many are being caught, according to the report. Among those that could disappear from Mediterranean and nearby waters in the coming years, it said, are bluefin tuna, sea bass, dusky grouper and hake – around all of which leading chefs plan favoured dishes.
The report, by the International Union for the Conservation of Nature (IUCN), also predicted a glum future for non-commercial fish like shark and non-edible ray and at least 12 species of bony fish which are shunned by consumers.
These, as well as dolphins, whales, turtles and birds which have no commercial value were swept up in trawling nets and illegal drift nets, putting their species’ survival at risk. The report said bluefin tuna in waters off European and North African coasts had seen an estimated 50 percent decline in reproduction capacity over the past 40 years due to intensive over fishing.
Based on latest research by IUCN scientists, the report was the first detailed assessment by the organisation – which links governments, environmental and nature groups and academic institutions – of the native marine fish for an entire sea.
Although some national and European Union quotas are in place for bluefin tuna in the Mediterranean and eastern Atlantic, it said, these were being widely ignored and catches were frequently under reported.
Overall, more than 40 fish species found in the waters between southern Europe and northern Africa could disappear within the next few years unless governments acted to enforce regulations, reduce quotas and create new marine reserves, according to the Swiss-based organisation.
The report, to be included in the IUCN’s running “Red List” of threatened species (www.iucnredlist.org), was released following another study showing that fast-warming oceans could be pushing many fish to extinction.