Marine Ecology Research

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  • Research projects available 2009-2010

    *Next fieldwork period from Augustus 2009*

    Are you looking for a research project for your MSc specialisation? AND:

    • Interested in Marine Ecology and Ecosystem wide processes?
    • Would like to participate in fieldwork in the Derawan Archipelago, East Kalimantan, Indonesia
    • Would like to gain experience in fieldwork in an experimental setting and in chemical laboratory technique
    • Highly motivated & enjoys working in field and lab?
    • Interested in being a co-author on a scientific paper?

    Then please send a 1-2 page CV and a letter with your motivation to me: m.christianen@science.ru.nl

    Background
    The objective of our project:

    • 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.

  • Enhalus acoroides in Marine lake!

    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 … Enhalus acoroides!! 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).

  • NH4 toxicity experiment

    After performing the same experiment with transported Thalassia hemprichii last year I wanted to test the same treatments in the field. So after some creative thinking I came up with this set-up (click for more pics):

    I’m (amongs others) testing if high ammonia concentrations could cause troubles to seagrass.

  • More Fieldwork at Derawan

    Time is flying. The enclosure experiment is finished and Laura and Madelon left for their holidays. Time for me to visit the civilized world and put some pictures on the internet. It isn’t very structured but that is because only emailing this pictures costed me 1 1/2 a small discription can be found next to the pictures. The last 3 weeks will be spend on performing an NH4 toxicity experiment and a comparison of seagrass productivity at an island close to the river compared to an island far from the river.

  • Berau and Monkeys

    Time for a presentatie for WWF, TNC and the local goverment in Berau about our research in Derawan. After a morning with presentations (Nina thanks for the translation in Bahasa Indonesia) and a very nice discussion it was time for a afternoon of jungle. We rented a boat and drove 0,5 hours from Berau to a small river where it was seeming with monkeys. The “Orang Belanda” Proboscis monkey was there and 4 other species. Not al pictures are sharp but more for the archives 🙂

  • Ongoing fieldwork

    Two months into my first research period I would like to update you on my progress. Because it’s almost impossible to post from my research location on Derawan I will show a compilation of photo’s. When I will be back in the Netherlands I will elaborate some more on the specific experiments. Click on the photo for all the research photo’s.

  • Turtles @ Derawan

    In the first week at Derawan I saw so many turtles, therefore a post about the “production of new turtles”. Yesterday night I saw 4 turtles (Chelonia mydas) crawling on the beach to search for a suitable site to lay their eggs above the high tide line.

    She digged out a large hole in the surface of the beach using a swimming movement of her front flippers, creating the “body pit”. After ten minutes or more, actively throwing sand behind her, she beginned digging with her hind limbs, excavating the egg chamber of about 60 cm deep. Without pausing she continued laying 90 ‘ping-pong-sized-eggs’ (While the eggs are being deposited into the egg chamber, they can tolerate bouncing, rolling, tumbling or handling, but about two hours after being laid, the embryo will resume development, and may be killed by a simple roll of the egg.) Ferry from the WWF digged up the eggs to protect them from poachers. Now we have to wait 45-70 days for the small Tukik (turtle hatchling in Bahasa Indonesia) to hatch. Higher temperatures produce more females and result in shorter incubation periods. At Derawan Ferry will check development of the nests so that he can digg the eggs out and release the small flippering friends before poachers or predators find them.
    After nesting, the female went back to the coral reef to rest and complete the next clutch of eggs. They are known to mainly rely on their stored fat reserved while resting and completing the next clutch of eggs. She can lay several clutches of eggs at approximately two-week intervals before finally migrating back to her feeding ground. We are still in doubt if the mother turtles are the same ones grazing on the seagrass fields in front of Derawan at daytime, or if they only visit this Island to lay their eggs and travel back to their feeding ground.


  • My first cage

    Before my supervisors arrive and the experiment will be started I’m first testing my cage set-up. The cages are build out of concrete-iron with fishing nets on the sides and on top of the cage, attached by cable ties. The net is 5cm in diameter to prevent the turtles from getting stuck into the net. Within the cage I’ve tested the best way to sample, harvest and count the seagrass shoots. And also tested how long it takes for the seagrass leaves to grow back. The locals are very interested in the strange things that I’m doing underwater so it’s never boring. I’m leaving to Balikpapan know to pick up my supervisors and check the seagrass in Balikpapan bay and after that the experiment can start. Finally! Click on the photo for more pictures.

  • 1st week pilot Derawan

    The first days I’m testing the set-up of my experiment, I’m snorkeling 4 hours a day to check out the seagrass and the turtles here (also found dugong grazing trails!), and I’m talking to officials here and setting up logistics at this island. The 21th of May my supervisors and students are arriving so I will travel back to Balikpapan to pick them up and do some measurements at Balikpapan bay.

    Derawan Beach Cafe

    At this moment I’m staying at Derawan Beach Cafe. It’s a convenient place with very kind people, good food (with vegetables, and nasi goreng as breakfast) 24hrs power, airco and a toilet to sit on. The only question is if I can stay here until september because the 300.000rp per night.

    For some more pictures click here!

  • Transport of research materials Balikpapan-Derawan

    Trying to find all the materials needed for research is one thing. Transporting them to Derawan is really much more adventurous. The rainy season is not over yet and the road between Samarinda and Berau is in bad condition and sometimes not excisting anymore. But this is the only way to get your stuff (if you’re also transporting liquids) to Derawan.

    So I chartered a car with driver, to get from Balikpapan to Derawan, like a Kijang (but next time I will charter a 4×4 car) This costed me 3,5 million rupiah and 36 hours travelling (you see why below!), sharing my chair with Dani, my assistent from Balikpapan. After this we arrived at Tanjung Batu at low tide, so I had to spend the night at the only losmen and take the boat to Derawan the next day 48 hours from the start of the journey.

    The other option is to send your materials with air cargo (Balikpapan-Berau and than arrange transport to Derawan via Tanjung Batu by car), which will cost 3000 rupiah/kilo excl car.