Microplastics and histological analysis of the digestive gland of the mussels Mytilus galloprovincialis Lamarck, 1819 from the northern Adriatic

Zbog nepravilnog odlaganja otpada, nedovoljnog gospodarenja otpadom i otpadnim vodama dolazi doznačajnog nakupljanja čestica mikroplastike u kopnenim, slatkovodnim i morskim ekosustavima.Ulaskom u ekosustave mikroplastika može imati znatni utjecaj na morske organizme, a posebice školjkaše. Cilj ovog rada je utvrditi broj, oblik i veličinu čestica mikroplastike u probavnoj žlijezdi dagnje Mytilus gallopovincialis uzorkovanena 6 postaja u sjevernom Jadranu (područja uz gradove Pula, Rovinj i Kopar). Provedena je histomorfometrijska analiza i semikvantitativna procjena atrofije mikrotubula probavne žlijezde dagnji. Najveći broj identificiranih čestica mikroplastike pronađen je u probavnim žlijezdama dagnji uzorkovanih na postaji Rovinj (30.2 ±29.9), a najmanje na postaji Katarina (8 ±2.4) i Strunjan (10 ± 0.5). Najzastupljenije čestice mikroplastike prema boji bile su bijele boje (91%), a najmanje zastupljene žute boje (1%).Prema veličini, najzastupljenije su bile čestice 5 – 10μm, a prema obliku film.Histološka analiza probavne žlijezde dagnji pokazala je da najveći utjecaj mikroplastika može imati na atrofiju probavnih tubula i smanjenje debljine epitela probavnih kanalića (Rovinj, Kopar). Atrofija probavnih tubula i smanjenje debljine probavnih kanalića pokazali su se kaDue to improper waste disposal, insufficient waste and wastewater management, microplastic particles significantly accumulate in terrestrial, freshwater and marine ecosystems. By in entering ecosystems, microplastics can have a significant impact on marine organisms, especially shellfish. The aim of this study was to determine the number, shape and particle size of microplastics in the digestive gland of mussel Mytilus gallopovincialis collected at 6 stations in the northern Adriatic (areas near the cities of Pula, Rovinj and Koper). Histomorphometric analysis and semiquantitative atrophy of the digestive gland microtubules were performed. The largest number of identified microplastic particles was found in the digestive glands of mussels sampled at the Rovinj station (30.2 ± 29.9), and the least at the Katarina (8 ± 2.4) and Strunjan (10 ± 0.5) stations. The most common microplastic particles by color were white (91%), and the least common were yellow (1%). According to the size, the smallest particles from 5 to 10μm the most represented, and according to the shape, the film was the most abundant. Histological analysis of the digestive gland of mussels showed that microplastics can have the greatest impact on the atrophy of the digestive tubules and a decrease in the thickness of the digestive gland epithelium (Rovinj, Kopar). The atrophy of the digestive tubules and decrease in the thickness of the digestive gland epithelium have been shown to be a useful tool for monitoring the influence od microplastics on changes in the histology of the digestive gland