Information about the entire intertidal Wadden Sea available for research and management

In SIBES, all tidal flats in the Dutch Wadden Sea are sampled annually for biomass and sediment characteristics. ‘Thanks to this long time series and the complete coverage of the Wadden Sea, SIBES offers a wealth of information that will provide new insights for science and management,’ says SIBES scientific coordinator Allert Bijleveld from NIOZ.

Four months of fieldwork

The Synoptic Intertidal Benthic Survey (SIBES) was partly the result of bird research on Griend. What do the birds eat there and where do they find that food? In addition, the Dutch Petroleum Company (NAM) was legally obliged to monitor the possible effects of gas extraction around the Wadden Sea. That is why NAM was also a co-financier of SIBES from the outset. In 2008, the first integral sampling of the tidal flats was carried out. Over a period of four months, a group of field workers walked (and sailed) across (and over) all the tidal flats of the Dutch Wadden Sea. They sampled every 500 metres of tidal flats with the addition of a number of randomly selected sampling stations.

Bottom animals and particles

They collected standardised samples of all organisms larger than 1 mm, the so-called macrozoobenthos. These were identified, measured and weighed in the laboratory. They also determined sediment characteristics, such as mud fraction and median grain size.

Millions of animals

This sampling campaign has been repeated annually, at more than four thousand points, spread over 1200 square kilometres of the Dutch mud flats. In the first fourteen years of the project, more than 50 thousand points were sampled in this way, and more than 3 million individuals of 177 different animal species were collected. In a publication in the journal Scientific Data, the researchers have now made this data publicly available.

The publication on the SIBES project, including the full dataset 2008-2021, is available via the website of Scientific Data: SIBES: Long-term and large-scale monitoring of intertidal macrozoobenthos and sediment in the Dutch Wadden Sea

DOI: doi.org/10.1038/s41597-025-04540-9