About Ionian Dolphin Project

Dolphins inhabiting the coastal waters of Greece are facing significant threats. Some dolphin populations must deal with increasing human encroachment, while others have disappeared altogether from portions of their former range.

The Ionian Dolphin Project aims to ensure the long-term viability of marine mammals living in coastal waters of the eastern Ionian Sea. Research by Tethys is providing support conservation efforts, through actions including:

  • continued monitoring of marine mammals through field research methods including boat surveys and individual photo-identification, to detect population trends and identify critical habitat;
  • research on factors threatening the local ecosystems, particularly excessive fishing;
  • public awareness, education and capacity building initiatives (e.g. involvement of a large number of students and volunteers, public awareness events organised locally, public presentations, lectures at local schools, production of multimedia);
  • contacts and meetings with the local Authorities and fishermen organisations, aimed to raise awareness on the need of establishing measures to protect marine mammals and implement existing regulations (e.g. to prevent illegal fishing);
  • dissemination of information in the scientific literature and delivery of management proposals to international agreements and bodies concerned with the protection of marine biodiversity.

The coastal waters of Greece still harbour a remarkable diversity of cetacean fauna compared to other parts of the Mediterranean. Yet, such richness is decreasing due to degradation of the marine environment. Research and conservation activities conducted in the context of the IDP are identifying measures to slow-down, halt or reverse such trends.

While today’s abundance of cetaceans is likely only a fragment of what it was a century ago, important populations still live and reproduce in the Greek seas. Moreover, in recent years, significant effort is being done by the IDP to urgently address the threats posed to Mediterranean monk seals within the Inner Ionian Sea Archipelago, as well as promoting monk seal conservation in the wider Ionian Sea.

Ensuring the long-term survival of healthy marine mammal populations must become a priority, as advocated by the EC Habitats Directive and the Marine Strategy Framework Directive and consistent with national commitments to preserve marine biodiversity.

Core Study Areas

IDP field station located in Vonitsa; Gulf of Ambracia

These study areas, home mainly to two dolphin species, are remarkably diverse in terms of environmental features and threats posed by human activities, therefore offering opportunities for understanding the links between dolphin status and habitat quality in different situations.

Inner Ionian Sea Archipelago

In 1991 the Tethys Research Institute began a study in the Inner Ionian Sea archipelago. Initially intended to be a long-term investigation on the ecology and behaviour of common dolphins in a central Mediterranean hotspot, the study instead became a documentation of their sharp decline.

Common dolphins, formerly abundant in the Inner Ionian sea Archipelago, suffered a dramatic decline between 1995 and 2007, which was convincingly linked to overfishing of sardines and anchovies, their main prey (See Bearzi et al. 2006, 2008, 2010; Piroddi et al. 2011b, 2017 included in IDP bibliography list). Unpublished data recently collected by the IDP indicate that these same dolphin individuals, which have reduced their occurrence in the Inner Ionian Sea Archipelago by 90%, are now using a much wider area along the coastal waters of the Ionian Islands, and occasionally still visit the Archipelago’s inner waters, but in lower densities; this is presumably caused by the area’s decreased carrying capacity due to overfishing. Monitoring of local fishing fleet and ecosystem modelling approaches indicated a specially adverse impact by purse seiners, making up only 3% of the total fishing fleet but removing on average 33% of the total biomass captured by local fisheries. Moreover, it is this kind of fishing gear the one that has the highest impact on common dolphin prey.

Bottlenose dolphins are also regularly present in the area but are in large part transient, occupying a wider area along the Eastern Ionian Sea coast (Bearzi et al. 2011). However about 20% of the photo-identified individuals display high levels of residency and stable trends (Bearzi et al. 2005). Our aim is to monitor their status with the objective of maintaining it at current levels.

Main threats here include negative interactions with fisheries and disturbance from pleasure boats. With respect to the latter, the number of recreational boats and flotilla sailing companies operating around the Ionian Islands has steadily increased during the last two decades. The activity of this large fleet not only offers a huge potential for the recording of opportunistic cetacean sightings (report your sightings here), but also calls for the design of adequate education and awareness initiatives addressed to boat users. IDP personnel has frequently witnessed sudden changes in behaviour by dolphin groups as result of the large concentration of recreational boats not maintaining a minimum distance or simply chasing them, which indicates that boat traffic and disturbance pose an added pressure on local cetacean populations and, as reported in other areas worldwide with similar scenarios, leading to the disruption of the dolphin’s natural behaviours causing them unnecessary stress. When being out there, please Be Dolphin SMART.

The Inner Ionian Sea Archipelago is one of the few Mediterranean areas where monk seals can still be predictably encountered, and some remote and uninhabited islets appear to be part of the species’ core habitat. The potentially adverse impact to this endangered marine mammal by fisheries and tourist boats poses particular concern. When being out there, please Be Monk Seal SMART.

Gulf of Ambracia

In 2001 Tethys started a study in the Gulf of Ambracia, also known as Amvrakikos (its Greek name), where bottlenose dolphins are the only cetacean species encountered.

Ongoing research showed that roughly 150 dolphins inhabit the Gulf. These dolphins are members of a highly ‘resident’ community, displaying unique behaviour and ecology. Research carried out by the IDP is documenting how the local dolphin community interacts with its environment and how human activities may influence its conservation status.

The Gulf – which is part of a larger National Park – is also inhabited by loggerhead sea turtles and has a rich bird fauna including rare species. The Gulf’s biodiversity, however, is threatened by high and increasing eutrophication and pollution.