Marjolijn Christianen

Last year I met Teresa Alcoverro and Rohan Arthur at the Turtle Symposium in India were we discovered that our research had a hudge overlap; we were both doing comparable work on ecosystems with very high densities of green turtles and declining seagrasses, and we only found this out just then. My lastest MS about habitat [...]

The Radboud University has recently updated it’s “virtual classroom” with interesting microscopy pictures of tropical seagrasses and other submerged water plants, check it out, (Thanx Liesbeth Pierson) There is also a movie in the virtual classroom (in dutch only) to explain students what kind of research we do at the department of Environmental Science .

Although this animal is already been found in 1996, this giant Archelon ischyros Turtle fossil of 70 million years old keeps impressing me.                       Its “flipper-span” reaches 4.9 meters and its shell 4 meters across. Imagine snorkeling next to this this turtle. Did these ancient already [...]

Update 1-6-2011: STUDENT RECRUITMENT CLOSED: both internship positions taken I have 2 MSc. student internship opportunities available with fieldwork in Indonesia from end of November 2011 till February 2012. Students should already have finished 1 other internship. Contact me this month if you are interested. Check for here for more info, or at the site of [...]

After months of blog-silence I finally have some news to share: The first paper of my Phd thesis is published in Aquatic Toxicology this month.

During our divetrip to the Similan and Surin island in the Andaman sea I found some seagrass (a Halophyla sp. >8 cross veins) growing very deep, between burrows of the shy spotted garden eels. While I know that some species are found much deeper, e.g. 50m deep (Beer et al. 1982) I was quite happy [...]

I just had a great time in Phuket and Trang in Thailand were the seagrass scientists of the world gathered for 11 days for the World Seagrass Conference and the International Seagrass Biology Workshop. Here a group picture of al the people joining the ISBW inside the Emerald Cave after surviving the 80 meters of darkness [...]

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 [...]

From May onwards it was finally time for data analysis and writing! My data folders look like these: And know its time to revise (ms 2), email the editor (ms 1), and wait for comments (ms 3). Thanx Phd comic for recognizable stories.

Before attending the symposium there were 2 obstacles to take: Waiting before it was safe again to fly from north-europe after the gigantic ash clouds following the  eruption of Eyajallajokull. And secondly, getting my businessvisa (3 days at the visa office) from the Indian Ambassy in The Hague. But the day before departure I finally received [...]

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 [...]

Finally, the Article that Arie and me published, is online: “Abundance, edge effect, and seasonality of fauna in mixed-species seagrass meadows in southwest Sulawesi, Indonesia” in Marine Biology research (fieldwork from my master-thesis in 2005). In addition Kiki Dethmers received her “Dr.” titel after her defence last week in Nijmegen, here is her thesis. So 2 [...]

From Christmas there wasn’t time to travel to the internetcafe on the mainland to update this blog because we preferred to do some extra experiments J instead of spending 2 day travelling. Now, I just arrived back home and I will give you a comprehensive update of the work of Sjoerd, Sarah and me the [...]

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 [...]

Tropical underwater Christmas (tree) worms are greeting you to wish you happy holidays from East-Kalimantan. Unlike in The Netherlands, here is no snow, no party but we celibrate the fact that we reached our goal of catching 300 turtles, with some rice, fish and onde-onde (sticky sweet green things)!  Cheers Marjolijn

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 [...]

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 [...]

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 [...]

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 [...]

This Autumn our seagrass researchers team from Radboud university Nijmegen and NIOO Yerseke visited our seagrass collegues in the Wadden Sea Station Sylt Germany. Besides the presentations we had some wonderfull excursions to the seagrass in the bay behind the institute. And our hosts Harald and Ragnild Asmus also to took us out to dinner [...]