Abstract
This paper explores the biological diversity of the mussel Mytilus galloprovincialis, its ecological functions, and its economic importance for local communities. By analyzing the ecological roles of mussels in the preservation of ecosystems, as well as their contribution to the local economy through fishing and aquaculture, the work provides a comprehensive insight into their importance and the threats they face. The aim of this study is to analyze the presence of the bacterium Escherichia coli (E. coli) and determine statistical significance in mussels collected from three different locations in Montenegro: Herceg Novi, Tivat, and Kotor. The analyses were carried out during different seasons, in a period of two years, 2022 and 2023. This approach enabled a detailed analysis of seasonal variations in the level of mussel contamination. Preliminary results show that the highest concentrations of E. coli were recorded during the summer months, which can be associated with increased tourist activities and a greater load on the sewage system. The lowest levels of contamination were registered during the winter months. This reduction occurs because tourist and industrial activity decreases, resulting in less waste and wastewater production. Furthermore, precipitation and winds that dilute pollutants increase, while lower temperatures slow down biological processes. Among the localities analyzed, samples from Kotor showed the highest average concentration of E. coli, while samples from Herceg Novi had the lowest values. These results indicate significant differences in the degree of pollution between localities and seasons, which can have serious consequences for human health, and the ecosystem. The presence of E. coli in mussels directly threatens the safety of food products, because the consumption of contaminated mussels can lead to various gastrointestinal diseases. Also, long-term pollution can disrupt the balance of marine ecosystems, affecting biodiversity and the stability of mussel populations.