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.
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.
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 same sites from the river to the open see we saw a lot of variation in species composition, algea cover, morphology. At the moment that I write this article Leon Lamers is travelling back to Nijmegen with +/- 10kg of dried seagras, sea water, and syringes with gas. Sjoerd will analyse the samples when he is back in february, we are looking forward to the results of the plant-nutrient analysis.
Check the photos to get an impression! And leave a comment, so that we also get some information back
We can also receive old fashioned post. Here is the adress:
Nama: Sekni AS
Untuk Ibu Marjolijn tinggal di Ibu Heldi Wisma Aditya Di Derawan
JL H.ISA III 66 Mardatillah No. 16 Rt / Rw 10
Kode pos 77311
Tanjung Redeb, Kab. Berau
Propinsi Kalimantan Timur, Indonesia
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 Lamers (ass. Prof. RU).
Jan and Leon will stay 2, and 2 1/2 weeks respectivily. Wawan and Arifin will support us from Jakarta, Sjoerd will stay for 3 and Sarah for 4 months. I will stay untill 13th of March and will post more about our research later on.
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 in a lot of blood. I wore booties but it stung right through the neoprene and rubber. At first I kept thinking it was a sharp shell or glass and not a stingray because I did not notice any pain from poison at first and I expected to feel something moving if it was a stingray.
I had some visions about me unable to come back to the field so we continued and harvested the experiment for 2 hours. Already halfway I got some suspicion that I maybe was a stingray, I was in a lot of pain and an hour later I was experiencing the most pain ever. Looking at the 400m distance that I have to walk back to the shore made me feel hopeless. The pain was up to my knee. Off course I know that the stingrays are there and I always walk with sliding movements, which scarred them away 300 times before when I walked in the same area but I was just unlucky this time.
This time I will be here for 6 weeks only, visiting seagrass meadows of Pulau Tikus (Pulau Seribu, in front of Java) and Derawan (Kalimantan) again. I am working together with Wawan Kiswara (the Indonesian seagrass expert from Jakarta) who is very helpful and has a never-ending hospitality surge. Together with his daughter Nina we had our first long fieldwork day in Pulau Tikus. In Pulau Tikus we could find mono-species meadows of Halodule uninervis like we have in Derawan Island, but the big difference is that here they are still ungrazed.
After 3 weeks we went back. Arriving in Jakarta from Derawan we left already the next day for the last fieldwork on Pulau Pari and Pulau Tikus. My planning was very tight, maybe a little bit to tight because Wawan and I already also worked for weeks without weekends and making long working days (7-22) every day but there is so much to do,! Based on the field station of LIPI on Pulau Pari (=stingray island without stingrays) we could reach Pulau Tikus in 30 minutes. I added some more pictures of the end of experiment on Pulau Tikus. The gaps in the ungrazed seagrass recolonized the sandy gaps (created 20 days ago by us) very fast. So the experiment was a success, now we compare it with the seagrass regrowth in gaps of in the grazed area of Derawan.
Click here for pix on the trip, the field site and the seagrasses we have seen.
After a long silence I’m know blogging from Jakarta again! After 3 days, which consisted of taking a motor taxi (Ocek), and bus way back and forth between Immigration, Police, Ministry of Internal affaires and RISTEK, I have my KITAS! 1 day delay because the Indonesian had to vote for their new president (SBY; Yudhuyono, it is!) but besides that, things went very fluently this 2nd time! I knew were to go, who to ask (& who not), practised my new skills learned from Bahasa Indonesia lessons, and all went so well that I actually enjoyed Jakarta. Off course, the manual “Researchers visa and permits for dummies” by Lisa and me was also very helpful for myself and I fine-tuned the last details so that you can read the last visa guide version (3.0) here. What also helped was maybe because I entered Indonesia in a very relaxed mode after 4 days recharging at Rock Werchter (Prodigy!)
If I’m with my nose between the seagrass I sometimes encounter camouflaged creatures which I would have missed if I wasn’t studying the seagrass. These encounters are most rewarding and will “make my day” If you have more examples of fauna mimicking seagrass, please send me your pics/movies. Click here to see some more seagrass associated fauna
The Robust ghostpipefish comes in several colours but the seagrass-green one is my favourite of course .
We wish to address the possible shifting states of seagrass in relation to eutrophication and turtle grazing, using field experiments in the Derawan Archipelago, Kalimantan, Indonesia.
In parallel, we wish to obtain insight in the variation in production and community composition of seagrass assemblages between sites at diffent distance to the river and relate this variation to spatial and environmental variables.
Most field experiments will be carried out in the coastal zones of the Berau and Mahakam rivers, East-Kalimantan, Indonesia. Ecosystems states (e.g. eutrofication, turtle grazing) and possible shifts between them will be provoked in a series of experiments involving turtle exclosures, turtle grazing mimicking and nutrient enrichments, both in the field and in the lab. The research will be carried by Radboud University Nijmegen (The Netherlands) in close cooperation with the Indonesian Institute of Science (LIPI, Indonesia) and the Netherlands Institute of Ecology in Yerseke.
What you will do:
Participate in fieldwork and exclosure-experiments. Participate in lab-work, collecting toxicity and biogeochemical data. We can discuss the details of the internship to create an exciting project that encompasses both your research interests and the goals of our project.
Your project could start in the middle of 2009, with fieldwork (3-6 months) starting from beginning of August 2009. Due to application deadlines of funding (and visa preparations) It is advised to start early < 6 month before the start of your project with the preparations.
In Dutch:
Studenten gezocht: Stage Mariene Ecologie Indonesie,
Als je op zoek bent naar een buitenlandse stage voor je master in Mariene Ecologie / Biologie lees dan bovenstaande beschrijving even door. Ik ben op zoek naar studenten die bereid zijn om voor hun master project ook veldwerk uit te voeren in het buitenland. Indonesie op het eiland Kalimantan voor verschillende maanden. Heb je interesse, neem dan contact met me op.
In august I visited Maratua for some measurements on the seagrass there. When I arrived the water was too high to work; time for some exploring! So I asked a man from the village about the marine lakes there. Off we went, through palm forests and mangroves with a “parang” cutting out our way. And then we reached this marine lake. The jellyfish were a lot smaller then those of Kakaban lake and the other more famous lake of Maratua. And when I reached the opposite of the lake I found … Enhalusacoroides!! I still have to check the literature but it’s very interesting to find this species here! This marine lake has a lower salinity (26-28‰) than the surrounding ocean (33%-34%) because of the filtering effect of the coral and years of dilution by rainwater. I know seagrass can cope a large range of abiotic factors but finding this species here suprised me. Do you know more about this, and have you seen this somewhere else? I’m pleased to receive your comment! The lake was also very turbid at the shore as you can see on this pictures (click for more pics).
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