In recent decades, the surging human population and expanding economic activities have led to a significant rise in maritime traffic, exerting heightened pressure on marine environments and the establishment of new marine trade routes. This rise in maritime traffic puts additional pressure on marine environments, with fuel spills thought to play a key role in environment deterioration. In this paper, we conducted a micronucleus test on 48 limpets of the genus Patella collected from four different marinas. Additionally, we collected 48 limpets of the genus Patella from a fifth site and exposed them to ship contaminants (fuels and cleaning products) for five days before conducting the MN test. Furthermore, we analyzed arsenic, cadmium, mercury, and lead (As, Cd, Hg, and Pb, respectively) in four water samples from the five sites. Our findings revealed that limpets from Gijón had the highest micronucleus count, followed by limpets from Avilés, Nalón, and Ribadesella. Limpets exposed to petrol showed the highest micronucleus count, followed by those exposed to diesel, ecological soap, and the control group. There were no statistical differences between limpets exposed to ecological soap and the control group. As was detected in all water samples, while Cd, Hg, and Pb were only found in samples from Avilés marina. These results support the hypothesis that maritime traffic may significantly contribute to the genotoxic effects of local marine fauna.