The SCS supports the Tethys Research Institute
for the protection of the Ionian Sea marine mammals

The Greek Sea still harbours a very diversified marine fauna, including several marine mammals species. At least 6 species of cetaceans are present throughout the year: The Striped dolphin (Stenella coeruleoalba), the Common bottlenose dolphin (Tursiops truncatus), the Short-beaked common dolphin (Delphinus delphis), the Cuvier's beaked whale (Ziphius cavirostris), the Sperm whale (Physeter macrocephalus) and the Risso's dolphin (Grampus griseus). In addition, sightings of Fin whales (Balaenoptera physalus) and Harbor porpoises (Phocoena phocoena) have been reported.

Unfortunately, such marine biodiversity is constantly decreasing due to degradation of the marine environment.

Since about 30 years, Tethys Research Institute is active in the internal Ionian Sea and the Gulf of Ambracia. With the Ionian Dolphin Project (IDP), it aims to ensure the long-term viability of marine mammals living in the coastal waters of the eastern Ionian Sea. These ones are: the Common bottlenose dolphin, the Short-beaked common dolphin and the Mediterranean monk seal.


In the context of the IDP, TETHYS organizes scientific expeditions in order to ensure the monitoring of the Ionian Sea marine mammal populations and collect data on factors threatening the local ecosystem. These data allow setting up efficient conservation measures and spreading relevant information to the public, local fishermen and authorities.

To actively participate in this project, register to an one-week field research in Greece,

directly on our partner site.

Grand dauphin_Joan GOnzalvo_Tethys - cop

Common bottlenose dolphin

Its population is negatively affected, because the Common bottlenose dolphin lives in the coastal areas, and is, therefore, more exposed to risks caused by human activities, such as incidental mortality in fishing gears, prey depletion due to overfishing, noise disturbance due to boat traffic, pollution and general deterioration of its natural habitat. While  the population of Bottlenose dolphins in the Ionian sea is actually estimated at around 120 individuals, the Mediterranean bottlenose dolphin is classified as « vulnerable » in the IUCN Red List.

Bottenose dolphin of the Gulf of Ambracia

The Gulf of Ambracia, located in the northwest of Greece, is almost completely enclosed and has only a narrow passage as an opening to the sea. It hosts the densest population of Bottlenose dolphins in the Mediterranean, which is not a proof of an optimal state of conservation, nor of an ideal habitat. On the contrary, the survival of the Bottlenose dolphin in the gulf is at risk because of the reproductive isolation, the limited population size (approximately 150 individuals), but also because of the negative impact of human activities, which are constantly increasing, in this semi-closed and shallow habitat.

Some other species have been observed in the Gulf area, such as loggerhead sea turtles (Caretta caretta) and a rich bird fauna including rare species. The Gulf's biodiversity, however, is threatened by high and increasing eutrophication and pollution.

Dauphin Commun_Joan Gonzalvo Tethys - co

Short-beaked common dolphin

Once one of the most abundant cetacean species in the Mediterranean Sea, Common dolphins have declined throughout the region since the 1960s. In 2003, their Mediterranean population was classified as Endangered in the IUCN Red List. Common dolphins in the Ionian Sea declined dramatically from approximately 150 to 15 animals between 1995 and 2007! Decline of Common dolphins has been linked to food resources exhaustion due to overfishing and fatal accidents due to collisions with boats.

Mediterranean monk seal

After having been considered critically Endangered for almost two decades, the status of Mediterranean monk seals, Monachus monachus, was downlisted in 2015 to Endangered in IUCN Red List, based on the observation that seal concentrations in specific locations had been stable in numbers, and even increasing.

Phoque Moine_Joan Gonzalvo_Tethys - copi

Tethys Research Institute is an international non-profit research organization active in marine conservation, with an emphasis on large marine vertebrates. To achieve its aims, Tethys uses primarily scientific research and public consciousness awakening. The « Ionian Dolphin Project »  aims to ensure optimal conservation conditions for the Short-beaked common dolphin; establish protection measures for the Common bottlenose, and identify risks threatening the local population of Mediterranean monk seal.

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Finance a day of field research
(150 CHF)
You will receive a supporter certificate with beautiful pictures of the supported marine mammals.
Support a population in danger with
an open donation (starting from 10 CHF)

You will receive a supporter certificate (for donations of minimum 50 CHF).

This money will primarily serve to protect and monitor
the Ionian Sea marine mammals in danger.


The pictures have been made available by:  © Dr. Joan Gonzalvo / Tethys Research Institute

The texts are based on:

  • Gonzalvo et al. (2015) Aquatic Conserv: Mar. Freshw. Ecosyst. 25: 91-106

  • Gonzalvo et al. (2016) Mediterranean Mar. Mammal Ecology and Conservation 1st edition :259-296.

  • Gonzalvo et al. (2011) Fisheries Management and Ecology 18: 25-38

  • Ionian Dolphin Project_Info (2020)