The scientific journal Marine Ecology recently published a study undertaken by the Italian Institute for Environmental Protection and Research, ISPRA (Istituto Superiore per la Ricerca e Protezione Ambientale) showing that frequency of occurrence of fin whales in the central Tyrrhenian sea increased by 300% over 20 years.
From 1989 to 1992 dedicated cetacean surveys along a trans regional fixed-transect in the central Tyrrhenian sea were carried out twice a week, using passengers ferries as a research observation platform. Collected data provided new information about cetacean species and their distribution in the region. From 2007 the research restarted with same protocol, the fixed line transect seasonally monitored the line from Civitavecchia (Rome district) to Golfo Aranci (Sardinia), along a strategic area just out of the southern border of the Pelagos Sanctuary.
Despite the environmental changes and the morbillivirus epizootic that occurred in the area during the two monitoring programmes, nor distribution, relative abundance or group size showed any dramatic changes for all species except for fin whale. Sightings of fin whale have surprisingly increased (+300%) and their spatial and temporal distribution showed a radical difference between the two periods. In both investigated periods the most common sighted species were striped dolphin (Stenella coeruleoalba), fin whale (Balaenoptera physalus) and common bottlenose dolphin (Tursiops truncatus).
Reasons behind the increase of animal in the investigated area could be linked to high levels of Chlorophyll and increase maritime traffic in the Pelagos Sanctuary.
ISPRA is within a network that monitors cetaceans using passengers ferries; types of observation platforms and cost of research, in fact, have been the main problems in the development of monitoring programs capable to survey cetacean population over time. Due to low costs, standard route, speed and height of the observation point, ferries are an efficient and cost-effective platform of opportunity for long-term monitoring programmes of cetaceans. The method has also been used to respond to the Habitat Directive requirement and for an assessment of the impact of maritime traffic in deep sea waters.
The 2000s surveys confirmed the existence of cetacean high density areas and the consequent need of conservation measures such as an extension of Pelagos Sanctuary southern border and the adoptions of specific measures in such areas.
The recent Italian Presidential Decree 209/2011, which established a Zone of Ecological Protection (including the Central Tyrrhenian Sea), expanding the Italian jurisdiction also in international waters, could facilitate the adoption of specific laws in this regard.
Partners of the network are, among the others, CIMA Research Foundation, University of Pisa, EcoOcean Institute, GIS3M, the MPA Capo Carbonara, Sicilian Ketos, Accademia Leviatano, Fondazione CARICIV and Pelagos France.