Abstract:

Marine litter is a global problem that affects oceans, producing serious disruptions of the marine environment. An important percentage of marine litter (around 80 %) is currently constituted by plastics that, once at the ocean, are broken into smaller particles mainly by photooxidation and mechanical degradation, being those particles with a size in their largest dimension between 0.001 mm and 5 mm named as microplatics (MPs).

MPs have been prevalent in marine ecosystems. They can be ingested by many wildlife species including marine organisms and seabirds. In particular, in the last years, the ingestion of MPs by fish has been an important issue of concern as a result of the possible effects that they may have in the food chain.

In Spanish universities, each undergraduate student degree includes a Final Degree Project (FDP) that consists in an autonomous work carried out in the last semester. In the FDP, which should be carefully written and presented in a public defence according to the specific guidelines of each degree, students have to demonstrate the competences developed. In particular, the Degree of Environmental Sciences of the University of La Laguna has 12 ECTS dedicated to the FDP, in which a bibliography research, an empirical approach or an experimental work may be developed.

This manuscript proposes an easy, interesting and cheap experimental work that can be developed in a laboratory as a FDP in the degrees of Environmental Sciences, Pharmacy or Biology, in which students have to determine the content of MPs in the stomachs of a specific species of fish. Students have to extract the MPs from the stomachs, digest the organic matter and visualize the sample using an optical microscope. Results can be taken as a measure of the conditions surrounding the studied species, showing the impact of MPs that come from the bad management of wastes or sewerages. Apart from the development of the educational competences proper of each degree, this kind of experimental work clearly contributes to the improvement and consciousness-raising about environmental problems which is of high importance nowadays.

Keywords:

Microplastics, fish, Final Degree Project, marine environment.