SANTA CRUZ DE TENERIFE, 17 May. (EUROPE PRESS) –
The magazine ‘Polymers’ has published an article that shows the presence of microplastics in the gastrointestinal tract of specimens of sea bream (Sparus aurata) and sea bass (Dicentrarchus labrax) from marine aquaculture farms on the island of Tenerife.
The work carried out by the Applied Analytical Chemistry research group (AChem) of the University of La Laguna (ULL), coordinated by the tenured professor of Analytical Chemistry Javier Hernández Borges, highlights the wide distribution of microplastics in the marine environment and the high degree of affectation by these pollutants that organisms suffer.
The study also points out that the problem is not unique and exclusive to the aquaculture sector, since, according to other recently published studies, similar results are observed in wild fish, the ULL details in a note.
To carry out this study, 86 specimens of fish, 41 sea bream and 45 sea bass, were acquired in different establishments in Tenerife, ensuring that the product came from aquaculture farms on the island itself.
All the specimens were dissected in an isolation chamber, proceeding to the subsequent digestion of the gastrointestinal tract to eliminate the tissues and after filtering the digested material, the filtrates were visualized in a stereoscopic magnifying glass.
The microplastics were classified according to their size, color and shape (parameters that provide information about their possible origin), and their composition was subsequently identified by Fourier transform infrared spectroscopy.
Of the 86 specimens studied, a total of 450 plastic particles were isolated, 208 in sea bream and 242 in sea bass, with an average of 5.2 particles per individual, mostly microfibers.
As for the colors of the fibres, there were many colorless/translucent ones (60.9% for sea bream and 47.7% for sea bass), followed by blue (24.8% compared to 35.3%), black (7 .9% compared to 8.7%) and red (5.4% compared to 4.2%).
In the case of sea bream, white and pink fibers were also found in 0.5%, while seabass had yellow fibers (2.5%), green (0.4%) and violet fibers (0.4%).
Regarding the composition of these materials, a prevalence of cellulosic fibers was observed in 56.1% (both natural and semi-synthetic), along with polyester and polyacrylonitrile, among other polymers.
The morphological and compositional patterns of the microplastics, similar for both species, coincided with other studies carried out by this same research group on marine sediments and sea urchins.
In addition, in 5.8% of the specimens analyzed, the presence of ‘microplastic tangles’ was detected, which constitute larger structures that could potentially obstruct the gastrointestinal tract of the fish.
ORIGIN: DISCHARGES OF WASTEWATER
In relation to the possible sources of the microplastics found, it was possible to conclude that they have a mainly anthropogenic origin, indicating the discharge of wastewater and treated water as one of the potential causes of the introduction of this pollutant into the marine ecosystem.
The research team points out that although the effects of the presence of microplastics on the development and physiology of fish are not entirely clear, the principle of prevention should trigger greater control of pollution in coastal areas.
Similarly, although the evisceration of fish for consumption represents a significant reduction in the risk of microplastics entering humans, it does not completely eliminate this possibility.
Therefore, it is necessary to continue conducting research in this field, not only in confined fish populations, but also in wild populations of the archipelago, they point out from the ULL.