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Ionian Dolphin Project

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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.


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.

Grand dauphin_Joan GOnzalvo_Tethys - cop

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.

An application for recognition of the Ambracian Gulf Bottlenose dolphin population as Critically Endangered has been filed by the Tethys Research Institute with the IUCN Cetacean Specialist Group in 2020 (see also RESULTS- ACTIVITIES 2020, below).  


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.

Dauphin Commun_Joan Gonzalvo Tethys - co

Mediterranean monk seal

Ionian Sea population

Monk seals from the Ionian Sea, which recent studies have outlined as being part of a subpopulation genetically distinct from Aegean seals, might still exist in a quite precarious state and might still qualify as "Critically Endangered". Information about its numbers, ecology and threats is scarcer than for Aegean seals, although pressure from fishing and tourist activities is quite high there. Approximately 20 individuals have been so far identified in the Eastern Ionian sea.

The IDP studies this sub-population of Monk Seals, which is considered particularly fragile because it is small, relatively isolated and not very well known.

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.




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.


The IDP activities include:


  • Continuous monitoring of marine mammals using field research methods, including data collection and photo-identification, to characterize populations and identify critical habitats

  • Research on factors, such as overfishing, that threaten the local ecosystem

  • Public awareness, education and encouragement of initiatives (e.g. local dolphin events, public presentations, lectures to local schools, multimedia productions). You can consult a guide on how to behave in the presence of a cetacean here)

  • Communication and meetings with local authorities and fishermen's associations, to raise awareness of the need to take measures to protect dolphins and monk seals, and to reinforce existing regulations (e.g. prevention of illegal fishing)

  • Dissemination of information through scientific publications and submission of management proposals to international bodies and authorities concerned with marine biodiversity. 



Within the IDP framework, scientific expeditions are organized (see our tab: Ecovolunteer Expeditions)

Actively participate in the protection of these fragile subpopulations of the Mediterranean and support the IDP
The funds raised will be used for the protection and monitoring of marine mammals in the Ionian Sea that are at risk.


Les images sont mises à disposition par: © Joan Gonzalvo / Tethys Research Institute

Les sources du texte sont:

  • 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)

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