Where Have All The Turtles Gone? 

We have lost contact with the two turtles that have been tracked via satellite – François Huet, the General Manager of Banyan Tree Vabbinfaru and Angsana Ihuru, explains how this could have happened and what this means for the future of the Green Sea Turtle Project.

22nd February 2003

Dear Friends,

It has been over a month now since we last received a satellite signal from our two “star” turtles. While we are wondering what happened to them, we have every reason to believe that they are doing well. Before going into specifics, let me say that the most likely scenario is that the turtles grew rapidly on the fat reserves they had accumulated under the care of Mr. Azeez and the hotel chefs, and as the carapace stretched it cracked the epoxy resin that cemented the transmitters to the shell. It is likely that the turtles are now swimming freely in the sea and that the transmitters are lying on the depths of the ocean. While this is disappointing for us from a scientific point of view, it is good news for the turtles, which have served a real purpose in teaching us about their journey across the ocean, a journey of adaptation to their natural marine environment.

Prior to losing the signals from the transmitters – which must not be equated with losing the turtles themselves – both turtles were behaving in interesting ways. One turtle (39067) spent a lot of time at the surface, allowing us to receive many signals on a regular basis. Turtle 39066 was obviously spending more time resting at the bottom of the sea and not actively moving around, accounting for fewer signal returns. What is important to note, though, is that both were indeed sending signals, just with different frequency depending on their activity patterns. Turtle 39067 moved around more and appears to have attempted a deep-water crossing on two occasions in an easterly direction, only to return to the confines of the archipelago. Then she headed west and just kept going. The initial track she took gives us an indication that she may have been heading for the Seychelles or the eastern coast of Africa, both known to have development habitats for green sea turtles. Turtle 39066, on the other hand, stayed closer to home, moving around mostly within the North Male Atoll. This is encouraging, because we know that the atoll is a suitable habitat for turtles.

That both signals were lost within days of each other allows us to speculate about the possible reason. We can rule out predation as a cause – given the distinctly different habitats the turtles were in, it is unlikely that they were lost to similar predators. Only a large shark or billfish could have eaten a turtle of that size. We can also rule out power loss, as the equipment manufacturers have analyzed the data from the signal returns and determined that both batteries were transmitting at full power. Signals were received daily until they stopped completely, which makes it unlikely that any major lifestyle change affected the transmitters. With the scant information we have, it is reasonable to conclude that in all likelihood a factor affecting both turtles equally, such as growth, was responsible for the transmitter loss.

Have all our efforts been in vain? Absolutely not! The number of people who have been touched by this fascinating research experiment is a demonstration of the project’s success in raising public awareness. The involvement of both guests and the Maldivian people in releasing the turtles into the ocean, the number of donations pouring in to support us, and the number of emails and comments received by the hotel staff are all testament to the overwhelming success of our satellite tracking attempts.

The project’s satellite tracking component was always intended as a research opportunity, and it has resulted in being just that. We have identified one potential problem with attaching satellite transmitters to growing turtles, and will take the difficulties of doing so into account when embarking on future initiatives. In the past, most transmitters were attached to mature turtles, many of which hardly grew at all. In our project we attached the transmitters to turtles, which were growing at an exaggerated rate – coming from a semi-captive environment with a special diet.

While the loss of an expensive transmitter is regrettable, the major cost of this project lies in the signals themselves, which are charged on a signal-by-signal basis. The funds saved by discontinuing the tracking now will simply be reinvested in the next tracking attempt. In future, we will release more turtles with transmitters using glue that provides a degree of elasticity, so that the turtles can grow without the transmitter falling off. Dr. Pilcher, our Scientific Advisor, is currently testing this method. We are also working with the manufacturer on making the transmitters fit the turtle carapaces better, thereby reducing the potential for transmitter loss.

We urge all of our supporters to continue monitoring the progress of this project, as the key objectives stay the same. We still want to determine if “head-started” turtles can survive in their natural environment. We also need to raise awareness, among individuals and the Maldivian authorities, of the urgency of marine turtle conservation around the globe.

François Huet
Area General Manager Maldives
Banyan Tree Vabbinfaru - Angsana Ihuru

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