A micronucleus test is a common test used as a biological indicator reflecting environmental genotoxicity caused by some of the hazardous substances’ presence, and due to this it is recommended as one of the indicators for marine environmental status assessment. To determine the status of the environment, herring blood samples were collected in 2014-2017 in the southern Baltic Sea area at seven fishing grounds. The conducted analysis revealed that there is no significant correlation between the number of micronuclei in erythrocytes and sampling locations each year. This could be a result of a similar chemical status of the assessed areas as well as similar physico-chemical characteristics, but also the individual condition of the examined fish has to be taken into account as well as the their size parameters (length and weight). Statistical analysis showed statistically significant differences between the results over the years of research. The highest median values in all locations occurred in 2017, in which they were in the range of 0.57-1.37, probably as a result of longer lengths. The threshold value was exceeded in 2016 and 2017 in all locations, indicating inadequate status of the marine environment.