Microplastics in the oceans
A dead whale was recently washed ashore on an island in Indonesia. Researchers discovered more than 6 kg of plastic in the animal’s digestive system. The freight consisted of more than 1000 individual fragments of various sizes. Marine creatures are now threatened not only by macroscopic scraps of plastic carrier bags, bottles, cartons and cutlery, but by an even more insidious foe – plastic microparticles less than 5 mm in size. Elsa and Lena, both MSc students at LMU, set out to examine the effects of such microplastics on marine life with the aim of increasing public awareness of the impact of this material on the world’s oceans and their inhabitants.
“A great deal of research in marine biology is devoted to species that we humans like to eat,” Elsa points out. That’s why she and Lena decided to study marine lifeforms that have received far less attention in the context of investigations on the ecological consequences of plastic debris in the sea. “Marine sponges live on food particles that they actively filter from the surrounding water. This inevitably entails the uptake of tiny plastic particles as well as food. So we asked whether the levels of these particles in the water can be determined from the concentrations that are ingested by sponges,” Lena explains. The experiments confirmed that their hunch was correct, and the results suggest that sponges could serve as useful indicator species in attempts to measure the degree of microplastic pollution of marine waters and coral reefs in the near future.
Professor Gert Wörheide, who holds the Chair of Paleontology and Geobiology at LMU and supervised the project carried out by Lena and Elsa, also believes that the outcome of their work opens up a new opportunity for the future: “Up to now, the concentrations of microplastics in the world’s oceans could only be roughly estimated. If the extent and the effects of pollution due to microplastics could be more comprehensively investigated and quantified, it would enhance our ability to protect coral reefs and marine organisms generally.” In light of the wider significance of their results, Wörheide nominated Elsa and Lena last year for one of the Lehre@LMU Student Research Prizes, and their “innovative and excellently executed” project was indeed among the winners selected by the expert jury.
Both awardees regard restoring the health of the world’s oceans as an urgent global issue. Lena intends to pursue the question further in her PhD project, while Elsa is now writing her MSc thesis on marine pollution caused by microplastics. A fortnight from now, they will be on their way to Indonesia. There, in the waters where the death of whale inadvertently drew the world’s attention to this pernicious source of pollution, Lena and Elsa will extend the scale of their research from aquarium level to that of the ocean itself. Their aim is to test the reliability and applicability of their laboratory model under more realistic conditions. In the meantime, they remind us that we can all make a positive contribution to the protection of the environment: “Using less plastic would be a good start. In the case of fruit and vegetables, there is really no need for plastic packaging.”
Lehre@LMU is made possible by the Pact for High-Quality University Teaching, which is a joint initiative of the States and the Federal Government. The program supports a wide range of measures designed to promote student research projects and innovative approaches to teaching, extend existing mentoring concepts and provide aid for students who find themselves in particularly trying circumstances.