Author: Marjolijn

Our second destination in our quest to find the green turtle foraging grounds was Raja Ampat. Some of the tracks of the GPS tagged turtles show foraging greens that travel all the way from Raja Ampat to Kalimantan. We were based at Kri with papua diving and did 2 short expeditions; 1 to Batanta & 1 to Wayag – Sayang. We planned our route using the aerial pictures of Max Ammer and the tips of his friendly staff. During the first trip we saw a dugong feeding at dusk on Enhalus leaves in front of the mangroves. The majority of the seagrass meadows were strips of multispecies (incl Enhalus) meadows in front of mangrove lined islands. Because we were the first foreigners to overnight in the village people did not know what to with us and we ended up sleeping in a empty information house on the jetty. In this area the fisherman are mostly Biak people that migrated here some decades ago. The Biak people explained us that green turtles are still hunted because of the tasty meat, in contrast to dugong meat that they did not like too much. Hence not too many foraging turtles, but a very nice trip. Here is a map of our trip and below it, you can see images of the trip.

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After spending so much time on Derawan where green turtles are so abundant we wanted to compare Derawan with other foraging grounds in Indonesia. Wakatobi was our first destination. In contrast to nesting sites of which a lot is known. It is unclear where the green turtles forage in Indonesia, so the majority of the time we spend searching for foraging grounds. The local Bajau people spend all their time at sea and were the most helpful in pointing us in the right direction. The Bajau is the same “tribe” that settled in Derawan but in contrast to Derawan they do hunt adult turtles. So the further away from the villages the most likely to find foraging grounds. In Wakatobi, green turtles graze in highest densities on the South reefs; Karang Kapota, Karang Tomia, Karang Koko and Karang Kaledupa, and around the outer Islands were they also nest. Pulau Runduma, Pulau Anono, Maramoho.

Overall we spend our most time looking for the turtles instead of finding them. We did several surveys of seagrass meadows to look for grazing evidence and suitability for grazing. The turtles we found most were Hawksbills and not the Greens we were looking for. But there is some evidence that on the South reefs the densities are far bigger. Time to go back some day. An impression of the conditions can be seen below.

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Just got back on the mainland. Last month we succesfully set-up a large experiment on Derawan to look at interactive effects of hydrodynamics & turtle grazing on seagrasses. This involved building 30 cages and 15 large underwater wave-bunkers for which we almost used al the sand from the nearby sand spit. To determine the location of the plots we used an unmanned aerial photo plane. A small disaster happened and the plane crashed in the telephone tower, and the plane is now in Switserland for repair. See below for a photo-report of the last month: