Dozens of dead dolphins washing up along the Mediterranean coast have alerted environmentalists to a virus they fear will become an epidemic, El Mundo newspaper reported on Wednesday.

The region's striped dolphins, a protected species, are being infected with a virus which has not been identified and has so far killed several dozen animals along the coast and may spread, the report said, quoting environmental experts.

"We are at the start of an epidemic," Javier Pantoja, a marine conservation official at the Environment Ministry, was quoted as saying.

An Environment Ministry spokesman confirmed that a meeting on the issue would be held in September to try to coordinate action between Spain's autonomous regions, but could not give details of the virus and its effects.

The virus is the latest in a series of difficulties facing the Mediterranean environment. This summer, beaches have been hit by a plague of jellyfish believed by climate experts to be due to warmer sea temperatures as well as over-fishing of predators such as tuna.