Underwater construction and pilot with turtle-mounted camera’s

Oct/Nov 2019: Time for one of the craziest fully packed fieldwerk trips I’ve ever been on!

Firstly, I went to Bonaire with 4 students, where we worked really hard to set up a new turtle exclosure experiment, a fish exclosure experiment and a bioturbation experiment. We had a great team and worked for long days and spend many hours underwater.

For our experiments, we’re investigating top down and bottom up impacts of nutrients and fish and turtle grazing on native and invasive seagrass growth and ecosystem services. The students got introduced to scientific diving and quickly developed their underwater construction skills.

We took seagrass samples, processed them and I tried to transfer all my knowledge of relevant seagrass research methods. We also built baited remote underwater video stations to investigate shark presence, behavior and diversity on Bonaire.

Then it was time for the second stage of our trip: to see if we could fit these camera tags on green turtles foraging in Lac Bay, Bonaire, to find out more about their grazing preferences and behavior within the bay. Marjolijn arrived from the Netherlands to help, and we were good to go!

The next day we fitted our first turtle with a cameratag, in collaboration with sea turtle conservation Bonaire. The method seemed succesfull and the camera stayed on nicely and the turtle seemed not to mind by observation after release. Tags were programmed to release after 20 hours.

However, finding back the cameratags proved to be incredibly difficult. Our retrieval equipment did not work as expected, and several times our boat broke down. After searching for days we only found back 1 of our tags, and then it was time to go to our next destination…

Eleuthera on the Bahamas! Here we would work together with CORE institute (clickthrough link through photo) on seagrass experiments and shark-turtle-seagrass interactions, together with Owen and Enrique, more of that soon.