Whales in the Mediterranean: more common than you think

People tend to think of whales as dwellers of oceans. But these giant marine mammals are in fact closer to us than most probably think.

The viral video of a fin whale just off Gozo’s Ta’ Sanap cliffs was once again a reminder of the wonders of nature that became more evident in the reduced human activity prompted by the COVID-19 pandemic: a rare encounter with creatures we only witness in TV documentaries.

The video from Facebook user Melania Bajada gave viewers a treat as they saw the fin whale surfacing to breathe in Maltese waters.

Biologist Alan Deidun, director of the International Ocean Institute, believes the whale’s size undoubtedly makes it a Fin Whale – 23 species of whale have been recorded in the Mediterranean and Black Seas, from the small porpoise (1.5m) to the fin whale (20m).

Biologist Alan Deidun

“Although the total size of the fin whale population in the Mediterranean is unknown, an estimate for a portion of the western basin, where most of the whales are known to live, was approximately 3,500 individuals. 10 species of dolphins and whales are regularly found in the Mediterranean region. A further 13 species are vagrant and only occur occasionally in these waters,” Deidun explained.

Nine cetaceans are qualified as threatened in the Mediterranean basin, which include the Mediterranean populations of Sperm Whale and the short-beaked Common Dolphin.

Since 2001, the Agreement on the Conservation of Cetaceans of the Black Sea, the Mediterranean Sea and Contiguous Atlantic Area (ACCOBAMS), has worked for the development of cetacean conservation in the region.

Fin whales, or ‘balena kbira’ in Maltese, are species of baleen whales. The e annual migration of baleen whales has historically been described worldwide as a seasonal cycle of summer, feeding in productive high-latitude areas, and winter breeding and calving in warm low-latitude waters, where feeding is absent.

“Genetic evidence shows that Mediterranean fin whale individuals in this population are distinct from their North Atlantic counterparts, and a recent acoustic study has revealed the existence of two populations of fin whales in the western Mediterranean: one which travels back and forth between southern Spain and the north-eastern North Atlantic and a second, more eastern, Mediterranean-only population,” Deidun said.

The latter population, the resident Mediterranean fin whale population, deviates from the traditional paradigm of whale migration observed worldwide in three significant respects. The first being that they remain within the mid to low-latitude, semi-enclosed Mediterranean Sea year-round. However, some individuals stay in the broader north-western feeding grounds in winter months.

Secondly, they feed not only during the summer but also during the winter. Third, they may disperse from summer aggregation sites, using most of the Mediterranean Sea for feeding, breeding and calving at different times of the year.

“The fin whales which annually skirt our coasts form part of the latter population,” Deidun said. So during the summer, Mediterranean fin whales congregate in large numbers to feed in the Pelagos Sanctuary in the north-western Mediterranean, the region’s largest marine protected area designated by France, Italy and Monaco to protect marine mammals.

However, their destination during the rest of the year remained, until 2015-2016, a matter of debate, until the issue was settled through the deployment of satellite tags on a small number of adult fin whales through the collaboration between the General Direction for Land and Sea Protection of the Italian Ministry of the Environment, in the framework of the ACCOBAMS Agreement.

Satellite tags were deployed on fin whales known to briefly appear in the waters surrounding the small Italian island of Lampedusa, in the Strait of Sicily, towards the end of winter (February-March). “The project was commissioned to obtain specific data and information on movements and possible migration routes of fin whales and on their habitats in the waters surrounding the island of Lampedusa, and to verify and confirm the previous limited sighting data, allowing to correlate this information with those from the north-western Mediterranean within the Pelagos Sanctuary,” Deidun said.

The Strait of Sicily is characterized by the presence of fin whales and other cetacean species, to assess areas of the Mediterranean Sea that could require targeted protection and conservation measures, as well as for the identification of potential threats and the implementation of mitigation measures.

Deidun said in particular, the waters of the island of Lampedusa are considered as a winter feeding area for fin whales, which feed on the surface thanks to the abundance of krill, the small crustaceans which the whales feed upon, different from that of the Ligurian Sea, by diving to depths over 470m.