Image of the month: May 2020
Is microplastic harmful for herring larvae?
Our image of the month shows the student Mirian Arellano San Martín in the so-called NEMO hall of GEOMAR. Here she takes water samples from breeding tanks in which herring larvae are kept. The samples are then analysed for chemical properties. The series of experiments, to which the master student is thus contributing, is intended to clarify the question of whether microplastics in seawater can harm herring larvae.
Microplastics have been found in all parts of the oceans. While it has been proven that larger pieces of plastic can be lethal to many marine organisms, little is known about the effects of tiny particles on various organisms.
The herring is an important food fish. Led by Dr. Nicolas Ory (GEOMAR and member of the Future Ocean network), a series of experiments under laboratory conditions was to investigate the susceptibility of herring larvae to this new environmental stressor. Preliminary results indicate that neither the digestion nor the feeding behavior of herring larvae were impacted by the ingestion of microplastics, perhaps because the microbeads did not remain long enough (<24h on average) in the fish to induce detrimental effects. More studies are needed to test the effects of other types of microplastics (size, shape) on juvenile herring, one of the most important commercial and ecological fish species of the Baltic Sea.
By the way, the name of the experimental hall is not derived from the famous computer-animated adventure film, but from an earlier project with the same name. This project investigated sustainable nutrition with marine organisms (NEMO) until 2012.
