04 Feb

Can we estimate the exposure to river plumes for coastal ecosystems? During my PhD fieldwork in East Kalimantan I had the opportunity to collaborate with a multidisciplinairy team of hydrologists, physical geologists, modelers, coral reef biologists to study this. In this paper led by Ayi Tarya (Bandung Institute of Technology), Ton Hoitink (WUR) we found [...]

31 Jan

I had the opportunity to go back to Derawan for 3 more weeks of fieldwork, thanks to the Schure Beijerink Popping foundation. I gathered samples for food web analysis, checked the current turtle density and seagrass biomass, recaptured green turtles and made a new series of aerial photographs with a kite (with super assistant Sipke [...]

18 Jan

Our new paper is out in Proceedings of the Royal Society B! Green turtle populations have expanded so much in Indonesia’s east coast islands marine protected areas that they are adopting new feeding habits, degrading the ecosystem and threatening their own conservation. Read more about  “Habitat collapse due to overgrazing threatens turtle conservation in marine protected [...]

07 May

After all those weeks behind the computer I am already longing back to my view from my research base in Derawan, enjoy my time lapse video. Do you see the tide rising? 2 last hours of sun on a typical fieldwork day.

28 Mar

In total now we captured and measured more than 800 green turtles around Derawan and tagged 500 of them. The WWF guys (Udin, Darjon), some locals (Jeffrey, Tiar) and we catched them using the rodeo technique. This year we recaptured some individuals that we tagged previously in 2009 on Derawan Island. These turtles grew 3-6 [...]

21 Mar

The last fieldwork of my Phd is finished! While writing this blog post in Dubai on the way back to the Netherlands the dried seagrass samples patiently wait on the seat next of me, together with the other 70kg of equipment where I travel with. The first unofficial results are promising. On the aerial pictures [...]

25 Feb

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 [...]

18 Feb

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 [...]

05 Feb

I was delighted to be requested to provide an article for Seagrass Watch magazine. The articles is published in the November issue. You can download the issue from their site (my article is on page 6) or download directly from the Seagrass Watch site (big pdf of 22MB). Enjoy the reading!

25 Dec

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 [...]

27 Nov

And were back! To give you an idea of what we did before travelling to our remote fieldwork site, here’s a (simplified) checklist: Arrange research & travel permit, KITAS, letters for governors, certificate of good conduct police (10 trips, at least 3 days) Give presentation at World Delta Summit & follow EcoDynamic Design workshop Buy [...]

30 Sep

After our first meeting in Texel in 2009 our second meeting was in Samarinda, Indonesia. The university of Samarinda (UNMUL) hosted the meeting and in 2 days we were updated of the outcomes the 15 WOTRO/ KNAW Phd projects that are now running in the Mahakam and Berau river Delta, including my project. The projects [...]

13 Apr

In January, National Geographic Indonesia published a very nice map about the important habitats for the green turtles in the Derawan Archipelago. See low resolution map below. The Editor in chief visited Derawan and interviewed all goverment NGO’s and researchers (me) having something to do with the green turtles in November and he made a good [...]

23 Mar

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 [...]

25 Dec

Udayana University (Denpasar, Indonesia) and the joint program WWF Berau, was so kind to provide one of their fastlock gps systems (Sirtrack) to track a green turtle from Derawan to study the movement on its foraging ground. Jaya Rata came all the way from Denpasar to Derawan to attach the Sirtrack transmitter. He has tagged a lot [...]

25 Dec

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 [...]

21 Nov

After 1 week of preparation the penyu team arrived at Derawan. Here Ibu Heldi invested my last payments in improving her place. Now it feels even more like home and our own research station even! In the week that my supervisors are here we revisited the seagrass meadows that they sampled in 2003. Sampling the [...]

03 Nov

Yesterday I arrived in Jakarta and there we made our first group picture with our fresh t-shirts. This was also the presentation of the new penyu.nl logo (see below). Meet our new team. From left to right Sarah Engelhard, Sjoerd van der Zon, Jan Roelofs (Prof. RU), Wawan Kiswara, Arifin (LIPI Oceanography, Jakarta), me, Leon [...]

22 Aug

Derawan did not changed a lot since I left 10 months ago. This time Wawan and me came for only a few weeks to do 3 experiments on Derawan Island and to go to the other important Green turtle foraging grounds on Maratua (40km from Derawan) and Pulau Panjang (8 km from D).  What did [...]

22 Aug

And now a horror story about infections and dangerous animals, which combination was still lacking on this blog. Halfway my experiments I got stung by a stingray when I walked to the experimental site (knee-deep water). I felt something very sharp and hard stinging 5 cm into my feet, 3 cm under my ankle, resulting [...]