“Free of macroplastics but contaminated and full of microfibers”: this is how we could summarize the results of a joint research work developed by researchers from the Marine and Veterinary Sciences centers of our University, the Oceanic Platform of the Canary Islands and the Museu de Baleia da Madeira, within the framework of the MARCET Project (MAC/1.1b/149).
The scientific article (https://doi.org/10.1016/j.marpolbul.2021.113105), published in this year’s latest issue of the Marine Pollution Bulletin in open access and already available on the web, analyzes the stomach content of several cetaceans stranded in Macaronesia.
Specifically, the gastrointestinal content of twelve individuals from six species of odontocetes that stranded between 2018 and 2019 in the Canary Islands and Madeira was examined to detect the presence of marine debris.
In addition, the concentrations of eleven persistent organic pollutants (nonylphenols, bisphenols, phthalates and pesticides) in the muscle samples were analyzed using liquid chromatography.
Among the most remarkable results, it is worth mentioning that no plastic particle larger than 5 mm was found, except for two polypropylene labels that were found in the same dolphin. In contrast, all animals contained microplastics of various sizes, most of them being fibers (98.06%, n = 708). The predominant contaminants detected were bisphenols (4-984 ng/g) and DEHP (102-1533 ng/g). In addition, except for two individuals, all the animals had levels of pesticides in their tissues.
This work has allowed to establish a protocol for the study of the ingestion of microplastics in cetaceans, and tests the potential of microRaman spectroscopy to improve the understanding of the processes of alteration of microplastics.