To responsibly manage intensive aquaculture breeding process, the composition and abundance of meiofauna is monitored and used as an indicator for monitoring the state of the marine environment and changes in the benthos caused by cage farming. Meiofauna sampling has numerous advantages such as wide distribution, easy accessibility, the ability to react more quickly to various environmental factors, constant and close contact with polluted sediment, and short generation cycles of individual taxa. Nematodes are the most numerous taxa of the meiofauna and are widely used as indicators of the state of the environment. This work aims to determine the impact of fish farming on the composition and structure of meiofauna communities in the sediment, as well as the intensity and distance at which cage farming has a significant impact. The research was conducted at the fish farm near the island of Vrgada, samples were collected by autonomous diving at three stations: on the edge of the cage of the farm (i.e., P1), below the cage of the farm (i.e., P2), and about 700 m from the cage of the farm (i.e., REF) which is also a reference station, in three replicas. During the sampling period, accompanying chemical-physical parameters were collected, such as temperature, salinity, dissolved oxygen, and pH value of the sea. The purpose of this thesis is to gain new knowledge about the impact of cage farming in the Adriatic and the possibility of applying this method in future programs for monitoring the impact on the marine environment during the operation of the farm. The results of the research showed that the abundance of meiofauna in the sediment was the highest at the station immediately below the cage, while the biodiversity of meiofauna taxa is the highest at the reference station. The research established that the Nematode group is largely dominant at the station directly below the cage, and it has been proven that it is the group that is the most resistant to various disturbances in the environment. Also, by analyzing the structure of the community of rare taxa, it was determined that the biodiversity was significantly higher at the reference station compared to the other two stations. The results confirmed the impact of cage farming on the abundance and structure of meiofauna communities and highlighted the importance of regular monitoring as well as the use of meiofauna as an indicator for monitoring the state of the environment.