Hawksbill health needing close monitoring 

Turtle tracking through the use of photos to identify individual turtle movements around Rarotonga has continued for a second consecutive year. The ‘Citizen Science’ tracking program, has collected data from local individuals, the private sector, government agencies and visitors, all contributing to a better understanding of the movements of Rarotonga's turtles.

To date, the current database has recorded 102 turtles identified in Rarotonga from recent and old photos that date back to 2011. This includes 84 Green Turtles and 18 Hawksbill Turtles. Just this year alone, 25 Green Turtles were identified, with 12 of these individuals photographed in previous years. Three Hawksbill turtles were also added to the database as new individuals.

Of particular interest, two of the three hawksbill turtles found this year were located near the shore and appeared very lethargic. After close monitoring, the two hawksbill turtles ended up passing away. In both cases, the turtles looked emaciated and malnourished based on their concave underbody and frayed scutes on their shell.

Hawksbill turtles are listed as critically endangered on the IUCN RedList, and although found throughout the Cook Islands, they are nowhere near as common as the Green Turtle, which is  listed as Endangered. Hawksbill turtles can be differentiated from the Green turtle by their hooked hawk like beak feature, hence its name, and the shape of their shell scutes. They are omnivorous, so eat both plants and animals like algae and sponges, playing a crucial role in controlling sponges which would otherwise out compete reef building corals for space.

The two Hawksbill deaths identified in one year raise questions around whether there is a lack of food for Hawksbill turtles here on Rarotonga or whether an infection is possibly taking place amongst this species. This is an issue that will need to be monitored closely.

To assist in gaining a better understanding of what might be causing these Hawksbill turtle deaths, we can get photos of the Hawksbill’s facial pattern on its left side for ID, and observe its behaviour, in particular what it’s eating. If it’s a particular sponge, algae or jellyfish, this will provide clues as to what food sources could then be monitored for availability. 

A natural response to seeing or hearing about malnourished turtles could be to feed the turtles, though this is not advised. Feeding not just turtles but wildlife in general changes their natural behaviours and could end up doing more harm than good, like creating aggression in the turtles possibly biting people.

Overall, turtles play a key role in contributing to a healthy coral reef ecosystem through their natural role in the food web and transporting nutrients within the ocean. Today turtles found on Rarotonga also play a significant role in supporting the livelihoods of locals through the soon to be regulated turtle guided tours. With some indication of sickly Hawksbills presenting themselves, it will be important to increase the number of “eyes on the water” to track their behaviours to ensure we maintain both environmental and social benefits associated with turtles found on Rarotonga.