Stomach content analysis

Large quantities of waste are still being dumped in the North Sea. Northern fulmars, birds that look superficially like gulls, interpret small pieces of litter as food; they consume the litter, but cannot digest it. The stomach contents of dead birds are therefore analysed by us to determine the composition and quantity of this floating waste. This provides an indicator for the quantity of floating waste on the North Sea.

Methods

Since 1980, WUR has been investigating how much plastic Northern Fulmars ingest. Volunteers play an indispensable role in this research. Along the Dutch coast and on the Wadden Islands, they collect stranded fulmars, which are then brought to our laboratory in Den Helder. There, researchers remove the birds’ stomachs and rinse the stomach contents over a filter so that even the smallest plastic particles are collected. Under a microscope, the plastic is separated from organic material, sorted and weighed.

Fulmars are particularly well suited to stomach content analysis because they feed at sea and rarely regurgitate ingested plastic. Their stomach contents therefore provide a good indication of the amount of plastic in the North Sea and how this has changed over time.

View the latest results in the finders report and the research report. If you have any questions about the research into petrels, please contact Susanne Kühn

The most direct way to study a food web is to examine what an organism eats. A fish stomach may contain plankton, other fish or benthic animals. We study stomach contents of fish from commercially important species in the North Sea as well as non-commercial species, because knowledge about these species is often lacking.

Wageningen Marine Research and cooperating institutes conduct stomach contents research on beached harbour porpoises and other marine mammals to determine the diet of these animals. The diet research is based on otoliths, fatty acids, isotopes and the remains of prey animals.