Satellite tags placed on nesting green turtles, St. Eustatius

Based on the monitoring data on nesting turtles that Jessica Berkel and her team at STENAPA are collecting we were able to predict the turtle’s return to the beaches. For this we used the inter-nesting durations of the first green turtles tracks that were reported for Zeelandia beach, St. Eustatius. Equipped with a turtle box, satellite transmitters, our red headlights and the turtle research kit we headed to the beach and already after an hour of beach patrols we found a female green turtle. Continue reading “Satellite tags placed on nesting green turtles, St. Eustatius”

Guest post: Free-diver Laurent volunteering in St. Eustatius

During our fieldwork on St. Eustatius. Laurent helped as a volunteer to catch turtles. He also made some really nice video footage while free diving. His guest post:
“Being a volunteer in a scientific mission is very simple : You just have to listen to the Project Leader, and you have to be available anytime, sometimes very early, sometimes late. The Project Leader is generally very nice to work with, able to create the right atmosphere for everyone to participate, suggest, and bring his experience/enthusiasm to the mission. In that sense, confidence is the cement of the team.

Continue reading “Guest post: Free-diver Laurent volunteering in St. Eustatius”

All females? Experimental nest temperature assessments will show.

Sea turtle sex is not determined at the time of fertilization like in humans, it is set by the temperature level during nest incubation. Recently for some small island rookeries througout the Caribbean researchers reported a shift towards a more female dominated hatchlings/populations as nest temperatures slightly increased in these areas (warmer beaches result in female turtles). At St. Eustatius we will further asses the driving factors of sand temperatures in natural nest and experimental treatments, link it to nest succes, and compare these with that of other Caribbean islands and beyond. Continue reading “All females? Experimental nest temperature assessments will show.”

New Publication shows Dutch Caribbean turtles migrate into risky waters

Lisa Becking (Wageningen University and IMARES) and I, together with Sea Turtle Conservation Bonaire (STCB) ; Mabel Nava, Sue Willis and Robert van Dam have shown in a recent publication that sea turtles who breed in Bonaire, Caribbean Netherlands, migrate great distances of up to 3500km to reach their foraging grounds across the Caribbean in 10 different countries. Continue reading “New Publication shows Dutch Caribbean turtles migrate into risky waters”

New! Review on herbivory on freshwater & marine macrophytes

Grazing is an important driver of ecosystem functioning! Not only in seagrass ecosystems :). This paper is a result of a very nice collaboration with Liesbeth Bakker and other colleagues working on herbivory in other ecosystems.

Paper highlights: Continue reading “New! Review on herbivory on freshwater & marine macrophytes”

2 times cake: 2 cool new papers! How to keep seagrass as happy as a clam?

Today 2 papers of our group were published online! This papers are the result of a successful collaboration between the University of Groningen, NIOZ and Radboud University, The Netherlands

The first study by Els van der Zee et al. demonstrates that food web structure and complexity can be fundamentally shaped by  Continue reading “2 times cake: 2 cool new papers! How to keep seagrass as happy as a clam?”

Guest post: Jurjan’s research – turtle genomics

Within the Dutch Caribbean, green and hawksbill turtle rookeries and foraging grounds are found. Green and hawksbill turtles have been decimated by human exploitation and habitat degradation, calling for knowledge of population structure and demographic history. Here we investigate migration patterns in these highly migratory species and evaluate current population status. In other words: How many turtles were there and where to they go? Those are the central questions in my PhD which I will address using population genomics and ancient DNA. 

Last summer I’ve spent three months in the Dutch Caribbean collecting tissue samples for my research. Most samples were collected on Bonaire, but a significant amount were collected on Curacao as well. A few samples were collected on Aruba as well. As soon as the samples arrive I will start on DNA extractions and analyses! Jurjan van der Zee20150910MC109214

Continue reading “Guest post: Jurjan’s research – turtle genomics”

Little-Curaçao-green-turtle swims 3100 km in 3 weeks

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The track of green turtle female “MRC rentals” (after her sponsor) updated 10 october 2015. After nesting in Klein Curacao she swam 3100km in 30 days – and has now settled in Mexico, the foraging grounds in Chakmukchuuk or Laguna Manati.

Last week we* successfully placed a satellite transmitter on a big green turtle female after she nested at Little Curacao’s turtle beach. The signals of the ARGOS satellite are updated hourly and I am very happy to report that this female is swimming very fast in the direction of Nicaragua 1050km in the first 10 days. Continue reading “Little-Curaçao-green-turtle swims 3100 km in 3 weeks”

Satellite trackers show Bonaire green turtle habitat use

4 sub-adult green turtles that we caught in Lac Bay are now equipped with satellite transmitters to study their movements and use of the seagrass meadows, (see  photos below).

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Mabel (STCB) and me deploying the satellite transmitter

The greens that forage in the shallow Lac Bay area are typically sub-adults. Continue reading “Satellite trackers show Bonaire green turtle habitat use”