Marine Mammals & Sea Turtles

Observing & Monitoring



The North-Eastern Aegean Sea hosts some of the most important remaining marine mammal and sea turtle populations, and therefore constitutes a key area within the Mediterranean Sea - indeed at least 11 cetacean species are regurlay caught sight of there. One of these is the Fin whale, the only Misticeti and the biggest cetacean present in the Mediterranean Sea. The other 8 species are Odontoceti, a parvorder of cetaceans. It includes dolphins such as the Common Bottlenose and Risso's dolphin or whales such as the Harbor porpoise, which is classified as rare species since its presence has only been recorded in the north of the Aegean Sea. This part of the Aegean also hosts the Mediterranean monk seal, which is one of the most critically endangered marine mammals in the world, and three different species of sea turtles: the Loggerhead, the Green and the Leatherback sea turtle.

Cetaceans, pinnipeds and sea turtles encounter various threats to their survival. The cetacean populations in the Eastern Mediterranean for instance, can often be disturbed by fisheries, injured or killed by shippings. They also frequently suffer from habitat loss and degradation (chemical pollution), anthropogenic noise, when they are not live-captured (e.g. bycatch, entanglement in driftnet) or purposely killed. Moreover, climate and ecosystem changes can badly affect the available quantity of preys.

Even though different national and international commissions have been held and various agreements have been made in order to protect these species, no effective nor sustainable conservation measures for cetaceans are being taken in the Aegean Sea. And this lack of effective conservation actions has been worsening the threat status from several of these species.



The 18,000 km of greek coastline and its 220,000 km² of sea surface area, undeniably makes laborious the collection of data regarding the populations and strandings of marine mammals and turtles. The research carried out on these species is limited, and unfortunately, strandings rarely reported.

Since its creation, Archipelagos’ research has been focusing on the assessment of marine mammal populations. Its research and conservation work in the Aegean aims to fill up the basic knowledge gaps and broaden the knowledge concerning the least studied populations of rare and endangered species.



Archipelagos works in cooperation with international organisations dedicated to the protection marine mammals and turtles

The Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic area
The Coordinating Unit for the Mediterranean Action Plan Secretariat to the Barcelona Convention and its Protocols

Report a sighting or stranding

The Aegean Sea hosts an exceptional biodiversity. Although marine mammals and sea turtles are top predators, human activities often affect their live conditions and some of them end up being classified at risk by the IUCN (the International Union for Conservation of Nature). Discover below the research about the different species of marine mammals and sea turtles that can be found in the Aegean Sea.


The marine mammal research of Archipelagos Institute aims to monitor dolphins, seals, whales and turtles, as well as their habitats. The research take place in the North East Mediterranean basin, where very few data concerning these species are being collected. Once we are aware about the danger they can encounter, we can take the necessary measures to avoid these threats and combine our research with public awareness campaigns.

The research are focusing on the following fields... 

Cetacean distribution studies based on boat and land based surveys

Knowledge on abundance, trends and distribution of cetacean population is needed to increase marine conservation efforts, ecosystem models and spatial planning. Land based and visual line-transect surveys, conducted along pre-defined track lines, on ships with dedicated observers, are a couple of the most widely used methods to quantify cetacean occurrence and density over a large area.

Indeed the distribution of a species is affected by different biotic and abiotic factors. Information provided can then be used to update the regional conservation measures.

Studies around cetaceans' behavior and how it is influenced by anthropogenic activities

Behavioral analysis results using BORIS



Archipelagos’ behavioral study focuses on the analysis of specific ethograms. The data collected during surveys are statistically analysed thanks to innovative methods and softwares. The aim of this study is also to identify the influence of human activities on the life of marine mammals and to map their habitats (the places dedicated to hunt, to rest, etc.)




Ferry fixed-transect monitoring of Cetacean and litter

Transect map including Samos and the surrounding Islands


Archipelagos’ members use the ferry trips between Samos and Lipsi to gather as much data as possible about cetaceans. As the Ferry carries out its tour at the same time, on the same days of the week, collecting data is all the more relevant.






Assessing fishes' biomass with a multi-beam sonar

Multi-beam technology can help identifying cetacean's prey's habitats and therefore understanding their presence in certain area.

Encounter rates of Delphinus delphis in the study area (b) Encounter rates of Tursiops truncatus in the study area, Feb-June 2017


Analysis of the environmental factors influence on the distribution and abundance of Cetaceans


Certain sea water's properties (temperature, temperature-depth profile, surface salinity, oxygen concentration, depth and pH) can influence cetaceans' distribution.



Movement pattern, residency pattern and social structure through mark recapture photo-identification techniques

This method enables to have a complete census of the presence of a population in a specific area, and helps creating a Photo-ID catalogue for each year. When it is not possible, a population study as well as a Photo-ID study could be used for a predictive estimation of the population's density. The photo identification can efficiently help implementing protected areas.

Numerous individuals have been identified within recent years: 2015, 2016 and 2017. Among these dolphins, several have been proven to return to the area. New data is collected on a weekly basis and is used to track residency patterns as well as habitat preference and social structure.


Aegean Marine Life Sanctuary: the creation of a multi-purpose center in Greece for the rehabilitation of stranded marine fauna and formely captive dolphins

The Aegean Marine Life Sanctuary aims to be the first refuge in the world providing a solution for the long term retirement of dolphins which are only used to life in captivity. It will give the dolphins the opportunity to learn their innate natural behavior again in semi-natural conditions, such as hunting for live fish. To read more about it, click HERE


Archipelagos Stranding Response Network

Over the last decade, the Archipelagos Stranding Response Network has been developed with the cooperation of local communities in the Aegean Islands. It helps providing first aid and rescuing stranded, entangled and entrapped animals, as we can intervene straight away when such cases are reported.

Monitoring the Mediterranean Monk Seals

As the Eastern Aegean region is home to important populations of Mediterranean Monk Seal, Archipelagos is also carrying out research on this important endangered species. Their interactions with fishing communities, as well as other threats, have to be monitored in order to develop and enforce realistic conservation and urgently needed schemes.

Microplastic/Macroplastic: marine debris monitoring and assessment on shore

The Archipelagos Microplastics Team is working on the dissection of dead cetaceans and sea turtles around Samos Island. These analysis are conducted in order to quantify microplastic particles and to understand how this global problem affects these species.

The Macroplastic project primarily focuses on measuring the influx of waste items into the Aegean Sea and onto certain beaches around the main Archipelagos base. Human activity has a significant impact on the health of both marine and terrestrial ecosystems. The debris found during beach clean-ups are then analysed and cataloged. On the other hand microplastic research focuses on the measurement of its concentration in both sea and freshwater, as well as its effect on marine fauna and human's health.

The project also aims to increase public awareness about the detrimental effects of littering on beaches and aims to increase awareness on a wider scale.

Eco-navigation: a guide for sailors and sea enthusiasts to report their observations in a citizen science database

The aim of this project is to create a citizen-science platform about the observations of marine mammals (dolphins, whales, seals), sea turtles, invasive species and jellyfish blooms, as well as pollution incidents (plastic debris, oil slicks, etc.) or other unusual sightings. This platform works with the help of sailors, divers, fishermen and sea enthusiasts who can provide information and photographs from their observations.


Citizen science and School education and awareness projects

The Archipelagos’ team is active in various parts of the Aegean region, involving and engaging the island communities in its research and conservation efforts.  A wide variety of media material is produced to raise awareness, including leaflets, posters, booklets, children’s fairy tales, educational games and DVDs. Various events to raise awareness, such as workshops and conferences, also take place in island schools and communities throughout the year. For Archipelagos, this important investment is the key to long-term protection of the Greek seas and the entire Eastern Mediterranean.

Video and photo of Cetaceans for conservation campaign projects

Video and photography footage of wildlife ensure the documentation of studied animals. This data collection is essential not only for developing a variety of awareness campaigns but furthermore to get results for scientific studies.

Bioacoustics monitoring and recording of the communication of cetacean species

Bioacoustics is a multi-disciplinary science that combines biology and acoustics, thus referring to the investigation of sound production, dispersion and reception in animals.

The Marine Mammal Team bioacoustics research aims to estimate the noise level and to record the cetacean species calls in different areas of the Aegean Sea. The objective aspires to show a direct correlation between the difference in cetacean communication sounds and the increase in marine traffic in the waters around Samos using bioacoustics.


Deliberate killing, bycatch and ship strikes

Although it is much more unusual nowadays, as cetaceans are protected by environmental law, and killing them is therefore illegal intentional killing of cetaceans is still a big issue in the Mediterranean. Our mission is to record these deliberate killings in an official database but also to prevent them. We are also trying to prevent by-catch and ship strikes.

Depredation and fishing gear damage

Certains species of cetacean (e.g. common bottlenose dolphin), when findind fishing nets, take advantage of this opportunity to feed themselves, triggering catch loss or gear damage. We are conducting research to estimate this problem's extent, and find preventive solutions.

Prey depletion and illegal fishery disturbance

Overfishing or destructive fishing practices can have devastating consequences on marine mammals' ecosystems. For example, blast fishing often destroys habitats.

Habitat degradation

Many things can explain the loss of an habitat, and most of them are related to anthropic activities such as mechanical and chemical pollution. The poor quality of an habitat decreases its attractiveness and endangers important and strategic areas e.g. areas related to feeding, breeding, socializing, resting, etc.

Chemical pollution

Chemical pollution affects the entire marine trophic chain, and is thefore a serious problem for marine ecosystems. Cetaceans, which are top predators, accumulate high concentrations of toxic substances in their tissues and become more vulnerable to health problems (e.g. hormonal disruption, immune suppression, reproductive inability, etc.).

Noise pollution

Anthropic activities are responsible for an increase of underwater background noise. Underwater noise is considered one of the most serious threats to cetaceans worldwide, as well as being one of the most difficult ones to address properly. Marine traffic, military activities, seismic exploration, oil and wind farm activities etc. can cause disturbance, discomfort, stress, harm to hearing, injury and death, while also masking biologically important sounds that are necessary for hunting prey.

Global Climate Change

Cetaceans are facing increasingly severe threats from climate change. This change may impact the areas in which they live and including their migration patterns. Global warming, and the depletion of the ozone layer resulting in a rise of UV radiation, may also affect the population of krill, a primary food source for many marine species. Even if cetaceans have some capacity to adapt to changing environment, climate change is now developing at such a fast pace that many populations could be at great risk.

Basic First Aid



Marine animals and sea turtles are stranded whenever they are found, alive or dead, on land or floating in the sea (usually on a beach shore, or in shallow water). Saving live animals isn't as easy as it looks, and if you are not aware of how to provide proper basic first aids you can do more harm than good.

The first thing you would have to do is to report the stranding as soon as you discover it. In any case, the main priority is to avoid causing stress to the animal, or moving it to deeper water, as this can often cause death.

Only trained experts can successfully manage a live stranding or conduct a proper post-mortem analysis, in order to understand the complex and multifactorial cause of death.

What should you do if ever you find a stranded marine mammal or sea turtle?

  1. Please note the place, the state of the tide and any injuries you can see without getting too close, call port police and the Archipelagos team. We will then advise you on what to do and will get a trained professional/medic out ASAP.
  • Port Police (Vathi) +30 227 3027318
  • Archipelagos Research Base: +30 227 3061191
  • For urgent matters ONLY: +30 697 4744949
  1. Avoid sudden and unnecessary movements, loud noises, close examinations and large crowds of people surrounding the animal.
  2. Check for movement from a distance. It might be normal for a turtle or a seal to stay on a beach; therefore they may not be stranded.
  3. Do not approach or touch the animal. Marine animals can carry infectious diseases that can be transmitted to humans with zoonotic implications and vice versa.
  4. After being in contact with an expert, following their instructions, keep the animal cool and wet, provide shade for the animal and ensure that the blowhole/nostrils are not covered and are clear of water and debris.

Archipelagos provides first aid trainings to ensure that trained volunteers can properly and efficiently respond to any stranding wherever they are. If you want to have more information about our first aid training, please contact us contact us.

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