In this bachelor thesis it has been made an analysis between the data obtained with ortophotography pictures from the years of 2011., 2014., and 2018. and with diving monitoring in September of 2019 on six sampling stations. The sampling stations include the following places in Rovinj: Cisterne bay, Veštar bay, Saline bay, faborso bay, then the port of Vrsar and Funtana bay. The sampling was done with the quadrat method. Three samples were taken at each station. After sampling, the samples were processed in the laboratory, and after that the biometric data were obtained. Biometric data include the average number of leaves per unit area, the average leaf length per unit area, the average wet and dry leaf mass per unit area, as well the average wet and dry roots and rhizome mass per unit area. Then by using the state Geodetic Administration Geoportal of Republic Croatia the area of meadow distribution is calculated for the years of 2011, 2014 and 2018. The area of meadow distribution in the year of 2019 is calculated by direct diving monitoring of the stations. The species Cymodocea nodosa was found on all the stations, and the species Zostera noltii was found in Veštar and Funtana bay. In the Funtana bay an invasive algae species, Caulerpa cylindracea was found. The condition of the distribution area and as well the biometric data was the worst in the stations of Funtana and Vrsar bay, the stations of Veštar, Saline and Faborso showed intermediate concern, and then the station of Cisterne bay was the least concerning in the term of biometric and distribution area stability.