Members of the Consolidated Research Group (GRC) in Marine Geosciences of the Faculty of Earth Sciences of the University of Barcelona (UB), with the collaboration of the Spanish delegation of the NGO Surfrider Foundation Europehave detected a high amount of microplastics in Catalan bathing areas. The results of study they have published in the journal ‘Environmental Research Letters’.
The professor and researcher at the UB, Anna Sanchez-Vidalstresses that the average concentrations they have found near the coast “are higher than those outside the bathing areas” and that even “at some points and times of the year” they exceed the Mediterranean averages by an order of magnitude.
The beaches with the most microplastics
According to the authors, these high amounts of microplastics indicate that “there must be processes that tend to concentrate or retain plastics near the coast.” Some explanations are suggested in the article, such as variations in meteorological and oceanographic conditions; a greater influence of floods in times of intense rain; the proximity to highly populated urban areas and of large tourist influx seasonal, or the concentrating effect of areas limited by groynes or ports.
“The beaches of Mar Bella or San Sebastià, in Barcelonamore are usually found sheltered from wind and waves by these constructions and could retain and accumulate more microplastics than more exposed areas, a fact that indicates a longer residence time”, explains William P. deHaan, UB researcher and first author of the article. In this sense, the points where more microplastics were detected were the Sant Sebastià, Nova Icària and Llevant beachesall in the Catalan capital.
In addition, the researchers also identified a possible seasonality: “We have observed that in areas such as in Llança (Alt Empordà) or Castelldefels (Baix Llobregat) there is a downward trend between January and February, probably due to the influence of surface currents and winds that reduce floating microplastics, and an upward trend just before and after the months of summer“, emphasizes the researcher.
Discover the origin to design effective solutions
The study has not only determined the abundance of microplastics, but has also provided a detailed characterization of the measure, the color, the form and the composition of the same ones.
The results show that foams and filaments —coming, for example, from food packaging and of the fishing activity— constitute almost 11 % of the collected plastics. However, the vast majority of plastics are identified as fragments and sheetspossibly caused by the breakage of plastic parts bigger.
How research is done
The investigation has started from the samples collected over seven months, from October 2020 to June 2021, by volunteers from fourteen entities from all over Catalonia. From Llançà to l’Ametlla de Mar (Baix Ebre). These volunteers have been coordinated by Surfrider Foundation Europe.
With a weekly or fortnightly frequencythe volunteers went out to surf for about an hour with surf boards, kayaks or other rowing boats. Hooked behind, the boats carried a net designed by researchers to collect floating microplastics larger than 0.3 millimeters.
Related news
The coordinates Tracks were recorded using a mobile device and the Wikiloc app to document latitude, longitude, time, and hauling distance. Next, the collected plastics were sent in laboratory of the UB to analyze them.
The next step of the project is to analyze whether the trends detected in this research are kept in time, what specific factors lead to the variations that have been detected and how the concentration of microplastics evolves in the short and long term. The project will continue in the coming monthsexpanding the sampling areas to the Euskadi coast.