Marjolijn Christianen

We explored the southern islands of the Berau Archipelago, Bilangbilangan, Blambangan and Mataha in search of more foraging areas for the green turtle.  In January 2010 National geographic Indonesia published a map + article on the green turtle in Berau. Turtle foundation is conserving the nesting beaches on these Islands and has posts on Bilangbilangan and Mataha were some very commited staff guards the turtle eggs. And you directly see the effect: On the Island without conservation posts eggs are stolen. A boat with poachers was directly fleeing when we arrived at Blambangan with our speedboat. This is the picture of a fresh egg forgotten by poachers that dug out the rest of the nest.

While egg harvesting is forbidden for some years in Indonesia local government creates their own rules and along the roadside of Samarinda and even on the local market of Berau you can still buy the ping-pong-ball-shaped green turtle eggs. Eggs are most likely from the few islands without conservation posts like Blambangan.

In the rainy season and the rest of the northeastern monsoon the number of females per night laying eggs is less but on the islands we visited it wasn’t difficult to spot them (there were still 7 that night) and in the afternoon we also encountered mysterious spots of moving sand after which more than 100 tukik per nest emerged. It is like Kill Bill 100-fold!

Like all organisms turtles development of hatchlings also sometimes fails. Here the TF guards showed us a tukik (Indonesian for hatchling) without legs and a hatchling with 2 heads.

When we arrived back we want to measure the population size of the green turtles in the area so we recaptured a lot of green turtles by rodeo method to check for tags.

All with help of Dodi, Jeffrey, Tiar and Darjon, who normally also help WWF/TNC. We used waterproof marker to prevent recapturing the same turtle. 1 of the turtles missed part of his front flipper (@pic right below). We also encountered a lot of turtles with cuts in their carapace (below-left), presumably caused by speeding speedboats around the island. If you see a turtle with tagnr 2722.. – 2725.. email me!

The special thing about this research area (Derawan, Indonesia) is the high density of Green turtles (Bokok in bahasa Bajau, the local language). Last year we found 1 turtle per 30 square meters of seagrass. However on the different feeding grounds densities differ, possibly regulated by the availability of food, seagrass. In the last 2 weeks we visited 3 islands Derawan, Maratua and Pulau Panjang (east-Kalimantan, Indonesia) and we catched, measured, painted and tagged 300 turtles. 

The sizes (of the carapace) ranged from 40 to 112 cm, the weight from 8 to 116 kg’s. The most of them were catched in nets by a team of us; Sarah, Sjoerd and me, and 4 enthusiastic Derawanese locals in a fishermen’s boat. For 3 days the local assistants of Pak Rusli from the WWF-TNC joint program Berau catched extra turtles with the rodeo method by jumping from a speedboat. The coming month we will try to spot our tagged/painted turtles back, so that we can learn about their movement and the population size. In addition we are also cooperating with Udayana University to study the population genetics of these turtles.

Transport of the turtle from the net – boat by kano.

Even in heavy rain the crew is searching for turtles. See here the net of 100 meters in front of the village of Payung Payung, Maratua.