How do we know that the turtle in the photo is unmistakably “Agisilaos”?
No doubt you have noticed the ease, with which sometimes we refer to specific sea turtles. It seems natural to give the turtles names in the Rescue Centre, but what about who is who at sea? The answer lies with the “tagging” processes that are in use in ARCHELON projects and also worldwide. Below you will find more on info on the this subject.
Giving an identity to wild animals is a fundamental way to study their populations. This has been the case for sea turtle populations since the very start of their conservation back in the 50s. In fact one has to think hard to find sea turtle studies where the identification of individuals through some "tagging" process does not play any role in one way or another. For instance by tagging nesting females one can follow their reproductive history for as long as these females are encountered at the nesting beaches, as well as to record their whereabouts in other areas and seasons. Growth rates of individuals can also be monitored at both nesting and foraging grounds, in the latter case via the so-called mark-recapture studies, where individuals are caught, tagged and released in a few minutes.
Which are the different ways that one can "tag" a turtle? The most popular method that has been used for more than half a century is via metal or plastic tags that are placed to the turtles' flippers. These tags bear a unique identification number that can be easily recorded by anyone who encounters the turtle. The method is cost effective, does not require any previous experience or equipment to "read" the tag but on the other hand "tag loss" that is, the fact that these tags often do not remain in place for ever, remains a challenge.
On the other hand, PIT tags (Passive Integrated Transponder) provide a more reliable solution. These are small circuits that are inside a glass capsule that has the size of a rice grain. They are inserted into the turtle's arm with a sterile injection. A special scanner is then able to read the tag which provides a unique ID code. PIT tags are considered to be more permanent than traditional flipper tags. However one drawback is the increased cost per tag as well as the need for a specific scanning equipment necessary to read it.
Another possibility is photo identification, where one exploits the fact that the "scales" (scutes) of the head form a pattern unique for every turtle, like the human fingerprints. This technique has specially come to rise after the advances in digital photography. This form of tagging is permanent as is the scute pattern throughout the sea turtle's life. It is cost effective and requires no handling of the animal since a simple photograph of good quality suffices. However, the matching process, that is examining whether a newly photographed individual exists in a given database, is often time consuming. Nevertheless, automated matching algorithms are constantly being developed and improved, often reducing a lot the time required for the matching process.
Finally, genetic tagging has been recently used successfully, with a prominent example that of the loggerhead population of the south east United States. For example there, an egg from every clutch is collected (or skin sample in other projects), and the genetic profile of the mother loggerhead is extracted and stored in a database. Hence in that case, it is not even necessary to encounter the animal in order to tag it. This has provided some unique insights into the nesting dynamics of the studied populations. In certain cases, mother-daughter or sibling relationships are identified opening new horizons in answering some important demographic questions, like for example age at sexual maturity. However, the increased cost as well as the requirement for highly specialized personnel limits these methods to only a few parts of the world.
ARCHELON has been tagging nesting females at the most important nesting sites of Greece since the beginning of the 80's with thousands of individuals tagged so far. Also ARCHELON has been PIT-tagging nesting females in Kyparissia Bay since 2005 and in Zakynthos. Furthermore, males as well as immature turtles are tagged in the mark-recapture project of Amvrakikos bay. For that, metal and PIT tags are typically used and occasionally photo identification as well.
(text and photos by Kostas Papafitsoros)
The victim was a sea turtle everyone was trying to see and admire
ARCHELON’s Lakonikos bay project has a big heart!
- OUR NEWS02/02/2024
Sea turtles in the Greek wetlands of international importance
World Wetlands Day is celebrated every year on February 2. These vulnerable areas of the planet are a refuge for migratory birds and other wildlife species, including sea turtles. ARCHELON is present in wetlands that play an important role for sea turtles, such as the Amvrakikos Gulf.
- OUR NEWS24/01/2024
Why are ARCHELON’s projects international?
ARCHELON’s sea turtle conservation projects are organized with the valuable contribution of volunteers who come to Greece every year not just from Europe but from more distant places such as South Korea, Australia, and Colombia. Speaking English while carrying out fieldwork or public awareness activities as well as when interacting with each other in the campsites is essential to the projects.
- OUR NEWS17/01/2024
ARCHELON has been running a special hospital for sea turtles with tanks and impressive old train wagons for 30 years in Glyfada
Turtles with IV and bandages, rehabilitation and recovery tanks, special environmental enrichment equipment, recovery greenhouses, and… renovated train wagons! The hospital for injured and sick turtles that ARCHELON has set up in the 3rd marina of Glyfada, next to the sea, is certainly something out of the ordinary.
- OUR NEWS05/01/2024
What happened in the world of ARCHELON in 2023?
A world record for reproductive life for a sea turtle and 40 years of ARCHELON’s actions for protecting sea turtles are some of the moments we celebrated together this year. So, what happened in the world of ARCHELON in 2023? Here are some highlights of the past year.
- OUR NEWS21/12/2023
Assuming responsibility for the environment brings more meaning into our lives
“ARCHELON is an opportunity, not only for the animals and the ecosystems, but also for us who participate in it and for the society in which we operate”. Thomas Arapis, President and founding member of ARCHELON, talks about the efforts of the organization and about what he aspires for the future.
- OUR NEWS20/12/2023
Forty years later: the world of ARCHELON has expanded
Thomas Arapis, President and founding member of the Association gives the current coordinates of ARCHELON. "We encounter many turtles in our daily activities, and even more people, many more people actually, who help us. Amongst them are the people who work for us, they stand out for they represent the Association out there, through thick and thin".
- OUR NEWS20/12/2023
19 Environmental NGOs ask the Greek Government not to consent to a change in the wolf protection status in Europe
- OUR NEWS15/12/2023
Messages of love from the world turtle community!
Celebrating ARCHELON's 40th Anniversary we have received warm messages from the turtle community worldwide
- OUR NEWS14/12/2023
When the past becomes a lighthouse for the future
Thomas Arapis, the President of ARCHELON and one of its founding members talks about the quality and values, and the people who marked the setting up and subsequent action of ARCHELON. “Dimitris Margaritoulis taught us, not only the methodology for monitoring and protecting them, but also what it means to organize tasks, take responsibility, work as a team, evaluate our course and cooperate with each other”, he says.
- OUR NEWS12/12/2023
Notes of a volunteer (Part 2): Ηead trauma happens more often and is more serious than you think
Jessica Van Damme who volunteered at the ARCHELON Sea Turtle Rescue Centre for 6 weeks in 2023, talks about what she learned while taking care of sea turtles with human caused injuries.
- OUR NEWS04/12/2023
Notes of a volunteer (Part 1): Jessica Van Damme was at the Rescue Centre
“During my 6-week stay, there were more than 30 injured sea turtles being treated at the Rescue Centre. Seven of them were successfully released, but, during the same period there were five new arrivals – all turtles with human-caused injuries. We, humans, are their biggest threat!”, writes Jessica.
- OUR NEWS30/11/2023
Summer 2024: Come back to sea turtle conservation as a leader!
Joining or returning to ARCHELON’s sea turtle projects as a Field Leader will give you the opportunity to lead specific activities as well as train and help others in the projects. These positions provide a higher level of experience in nature conservation/ environment protection, as well as improved communication and leadership skills. Hurry and apply now! Only a limited number of experienced and skilled volunteers are selected to serve as leaders in each project.
- OUR NEWS23/11/2023
The establishment of the “Amvrakikos Alliance”
The Alliance's vision in collaboration with the local community is to highlight the unique ecological value and the natural and cultural heritage of Amvrakikos, for the most effective management, restoration, and protection of its ecosystems and biodiversity.
- OUR NEWS16/11/2023
Kids Beach Competition 2023: Turtles made of natural materials that stole our hearts!
The little friends of ARCHELON who participated in the Kids Beach Competition 2023 formed turtles from pebbles, sand, water, rocks, sticks, leaves and shells, spreading the message of protecting sea turtles on the various beaches of Greece. Angeliki's (7 years old) little turtle on top of the big rock stole 694 hearts and became the winner!
- OUR NEWS15/11/2023
The Field Leaders of 2023 and their role
Matthew from the UK, Noha from France, David from the Netherlands, Aris from Greece started one summer as volunteers knowing little about turtles and their protection. Their experience made them return to the conservation projects as Field Leaders to take on more responsibilities, as trainers and mentors for new volunteers.