Rarotonga’s passages are key sites for spotting two species of sea turtles, the endangered green turtle and the critically endangered hawksbill turtle.

Commonly seen in the Avaavaroa Passage through tour operators, visitors and locals are likely to spot a turtle resting on a cleaning station or nudged into the side of an underwater coral facing edge. Though nesting of these turtles does not occur here on Rarotonga it is still a wonder exactly what their local movements are. Do our turtles check out neighbouring passages? How long is one individual likely to stay in one passage? Do the turtles travel beyond Rarotonga and if so, where do they go?

In an attempt to gain a better understanding of our resident sea turtles here on Rarotonga, Te Ipukarea Society will be piloting a citizen science programme to collect individual turtle ID data to help gain basic turtle population information.

Citizen science involves public participation from visitors and locals alike on our shores to assist with scientific research in collaboration with the supervision of researchers. If well informed and trained, citizen science can provide a cost-effective way of collecting data through increased manpower and sampling effort, allowing for greater biodiversity monitoring over time. The social benefits from engaging with the public through citizen science opportunities can also achieve educational value promoting knowledge, and greater appreciation towards nature. 

With swimming with turtles in Avaavaroa Passage now a popular tourist attraction visitors, locals, and tour operators can contribute towards the necessary data needed to supply population surveys through individual photo IDs.

The method of tagging sea turtles using flipper tags is intrusive and requires expertise. A shift towards individual photo IDs has become more favourable as it can be better achieved through citizen science skill sets. 

Similar to human fingerprints, the facial scutes of turtles are uniquely patterned for each individual turtle. Facial scutes provide a unique identification code that can be recorded and cross checked over time to determine individual movements. 

Te Ipukarea Society through the assistance of regional partners has been introduced to a software tool called I3S Pattern. I3S helps identify individual turtles to help visually monitor new and previous entries over time.

To help populate the database for Rarotonga, we are calling all citizen scientists now for your photographic assistance. In order to build the population database with useful photo IDs for recording purposes there are a few tips to take on board.

Keen underwater photographers are asked to prioritise photos that capture the left facial scute of individual turtles at eye level, to ensure photos are levelled. To capture a still shot, approaching turtles from the side is your best bet as opposed to swimming from behind or in front. A photo from a distance of 1.5 metres would be more than enough to identify facial scute features. If the turtle remains in position, do try for shots that also capture the right facial scute, the carapace (top shell), and any identifiable scars, the tail or underside of the shell. To assist with data analysis, at the end of each encounter take a photo of your fin to indicate the end of that record before capturing new shots. 

Photos provided for IDs should be accompanied by details of the location, date and time of encounters. These can be then shared with Te Ipukarea Society’s office main road Tupapa. Photos that have been taken already, with clear facial scute markings or carapace shots and the location and date details will also be of great value to the population database.

Turtles on Rarotonga are now getting a lot more attention from visitors and tour operators. There are new opportunities to capitalise on this generated attention to now gather turtle population data to not only inform local turtle movements around Rarotonga but also contribute to turtle conservation and its management. 

For more information email te.ipukarea.society.inc@gmail.com or call our office on 21144.