Marjolijn Christianen

In 2021 I was happy to be involved in the making of a documentary with Artist Mirthe Dokter, together with Rian van den Boom and others.

This unconventional docu shows an intriguing portrait of the leatherback sea turtle, threatened with extinction. In Ghana, artist Mirthe meets ‘Uncle Raf’, the leader of a turtle conservationists team in a small fishing town. Slowly, she gets entangled in the web of all the difficulties that come with protecting this ancient animal. Virtual artists Mirthe records her story in a painted diary, that she shares with a marine ecologist, Marjolijn, from the Netherlands.

Seagrass and Mangroves on Bonaire can use a helping hand. Water quality, tourists (trampling), Sargassum tides and more, have caused rapid decline of seagrasses and mangroves. Based on results from an earlier pilot, last week we launched a larger scale seagrass restoration project to help counter this decline. And also set up pilots to test the use of a new method for mangrove restoration alongside other ongoing methods. We used biodegradable mats that need only a little amount of donor material. The structure of these mats stabilize the sediment for the young plants to facilitate settlement, mimicking the natural effect of nature root mats.

One grazer is not like another. Where sea turtle grazing gives way to invasive eelgrass, fish grazing has the opposite effect. “Protected areas with abundant native grazing fish may be more resistant to expansion of invasive eelgrass.

WUR press release:

Seagrasses are important for our coastal protection, biodiversity and carbon sequestration. But contrary to popular belief, dense, waving seagrass meadows with long foliage are not necessarily more natural. In a new publication in Nature Ecology & Evolution, researchers from Wageningen University & Research and Radboud University argue for a more nuanced picture of natural seagrass meadows being dense vegetation interspersed with areas grazed by sea turtles. This calls for a change in our nature management practices.

_{Coastal ecosystems are in rapid decline around the world. Restoring them is very expensive and is often unsuccessful. But together with an international team of researchers we discovered a way of increasing restoration success of salt marshes and seagrass meadows, using biodegradable mats. Our findings are just published in Nature Communications (22 July 2020)}

In november Fee Smulders and I visited the Islands Bonaire and Eleuthera (Bahamas) to study the impact of grazing on seagrass ecosystem services. We look back at a very productive, and fun field trip, where we sampled and initiated multiple experiments.