Whales and dolphins of the Pelagos Sanctuary

The project focuses on the various species of cetaceans present in the Ligurian Sea, within the Pelagos Sanctuary, a Marine Protected Area located between south-eastern France, the Principality of Monaco, north-western Italy and northern Sardinia.

This area is particularly rich in nutrients, resulting in a massive presence of zooplankton, fish and cephalopods. These organisms represent the typical prey of cetaceans, which can be found in much higher concentrations in this area than in other parts of the Mediterranean Sea.

Dolphins and whales are usually sighted when the sea is calm. The striped dolphin is the most common species in this area, followed by the sperm whale, the fin whale and the Risso's dolphin.

Fin whales,

sperm whales,

Risso's dolphins,

striped dolphins,

long-finned pilot whales,

and Cuvier's beaked whales.

Common bottlenose dolphins and short-beaked common dolphins may be also seen, with a bit of luck.

Depending on the species, we take pictures of different body parts in order to identify single individuals, using a technique called "photo-identification".

For fin whales we need to take pictures of the dorsal fin and of the "blaze" and "chevron", based on particular pigmentation patterns located behind the blowhole and on the right side of the body.

Nicks, notches and whitish scars on the dorsal fin are the distinctive features used to identify individual Risso's dolphins and Cuvier's beaked whales.

Sperm whales are identified by the trailing edge of their flukes, which the whales usually lift out of the water before diving, as well as by body pigmentation.

Common bottlenose dolphins and long-finned pilot whales are mainly identified by the natural markings on their dorsal fins, while Cuvier's beaked whales are mainly recognised based on their pigmentation and the white scars on their bodies.

Once immersed, sperm whales are tracked acoustically. A hydrophone array towed by the boat allows us to listen to the typical sounds produced by large cetaceans. Thanks to this, researchers can track the animals, even for several hours.

Vocalisations of long-finned pilot whales, Risso's dolphins and striped dolphins are also recorded.

We can also estimate the body length of sperm whales thanks to a technique called photogrammetry, which involves the use of a digital camera and a laser range-finder binocular.

The diving behaviour of fin whales, long-finned pilot whales and Risso's dolphins is also studied.

Underwater movements, diving depth and swimming speed are monitored using a v-TDR (velocity time-depth recorder), which we attach to the dorsum of the animals by means of a suction cup (a harmless method).

Once a v-TDR has been attached to an individual, its radio signal is followed with a directional antenna. After detaching from the animal, the v-TDR is recovered and diving profiles are analysed.

Sometimes, when Risso's dolphins and long-finned pilot whales come to bowride, we use a sponge attached to the tip of a wooden pole to collect small fragments of skin for genetic analyses. This technique is uninvasive and the dolphins may not even realise they have been touched by the sponge.

Participants are involved in various research activities, from sighting shifts during the day to night watches, when weather and sea conditions are good enough to spend the night in the open sea.

They also help the researchers to collect scientific data including geographic location of sightings, dive durations, behaviour, group size and composition. In some cases, faecal and prey samples are also collected in order to obtain information on dietary habits of fin whales and sperm whales.

Lectures on cetacean biology and conservation are also given by the researchers. The skipper is always eager to answer questions about navigation and sailing techniques.

It is sometimes possible to swim and relax between sightings.

Researchers and project participants often listen to vocalisations recorded in the field and in the processing of digital photos of different cetacean species sighted at sea, in order to recognise different individuals.

In addition to cetaceans, the Pelagos Sanctuary is home to many other marine species, which can be sighted on a daily basis: a number of fish species, invertebrates, sea turtles and seabirds.

Together with the researchers, volunteers may be involved in creative cooking sessions.

A long day full of work and emotions ends with a beautiful sunset offshore, in the good company of a solitary sperm whale.

Volunteers take part in unforgettable experiences, staying in direct contact with the marine environment and its fascinating inhabitants, and often meeting people from around the world.

Project participants also have the opportunity of exploring beautiful sites and landscapes. If weather conditions are unfavourable, volunteers can participate in inland trips and visit the small town of San Remo or the Oceanographic Museum of Monaco.

"Pelagos" is the 58 ft motorsailer used to collect data in the Pelagos Sanctuary. The boat, spacious and very comfortable, is equipped with sophisticated instrumentation used for navigation and the collection of scientific data, and it has an inflatable craft sometimes used to get closer to the animals.

With its two masts the boat can sail and manoeuvre using a fully electronic system, that can be switched to manual at any time. The surface of the deck and the inside of the boat are covered with teak wood.

The skippers of Pelagos are members of the Flashvela sailing club in Sanremo and they are interested in environmental problems and sustainable tourism. They have collaborated with Tethys for a long time, gaining a solid knowledge of all the different aspects of data collection and research needs.

Most photographs in this page © Tethys Research Institute

Some photos: © Massimo Brega, © Alessandro Duci, © Marco Frini, © Luigi Pastorelli, © Dieter Paulmann, © Nico Schoßleitner/COER; expedition participants

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