Where have all the Mediterranean whales gone?

Stralsund (Germany): In 1999 France, Monaco and Italy signed the agreement that created the Pelagos Sanctuary, an international protected area dedicated to the safety of marine mammals, in particular the Mediterranean “Fin Whale” (Balaenoptera physalus).

Some studies, including recent research of an international environment organization, reported a population decline of Fin whales in the Sanctuary. However, a two year large-scale study presented at the 2010 European Cetacean Conference (http://www.ozeaneum.de/en/ecs-2010.html), held in the Unesco World Heritage town of Stralsund in Germany, documented a shift of the summer habitat of the Fin whales towards the borders of the Sanctuary. The research was undertaken by several Italian Universities and Scientific NGOs, networked by ISPRA (the Italian research Institute under the supervision of the Ministry of the Environment).

For two years the Italian research network systematically monitored, from passenger ferries, several trans-regional fixed-transects. Results showed that the frequency of occurrence of the Fin whales was much higher in the Gulf of Lion and in the Central Tyrrhenian sea, in areas of high Net Primary Production, compared to the central area of the Sanctuary.

The fact that Fin whales have changed their known summer feeding ground could be confirmed also by the long-term study (also carried out by the research network) that showed that along the Central Tyrrhenian sea the frequency of occurrence of the Fin whale increased, compared to 20 years ago, of more than 200%. In particular, most of the sightings occurred in an area of 20 NM which lacks any types of protection. In this area, conservation measures such as a Protected Area or at least a reduction of vessel speed (ship reduced speed) are urgently needed.

Networking research bodies undertaking systematic monitoring along fix transect using passenger ferries was shown to be an efficient and cost effective survey programme. The effectiveness of the survey methodology in monitoring trends, abundance and presence of cetacean, also in relation with environmental parameters and global changes, was also confirmed by the studies undertaken in the Atlantic Sea water where regular surveys undertaken from passengers ferries are also carried out, among the others, to assess the poleward expansion in the habitat range of warmer water cetacean.

Being cetacean good indicators to detect the state of the marine environment, European cetacean scientists, both from the Atlantic and the Mediterranean sea, call together on European Policy makers on the necessity of systematic surveys along fixed transects to monitor cetacean occupancy.