The territory of Montenegro includes three freshwater ecoregional units: the Dalmatian, the Southeastern Adriatic, and the Dniester-Lower Danube Ecoregions. The boundaries of the latter ecoregion in Montenegro coincide with the border between the Danube and the Adriatic Sea basins.
Based on the FEOW ecoregion system, the main part of the Adriatic coast of Montenegro belongs to the Southeastern Adriatic Ecoregion. A smaller part of the Adriatic Sea basin in Montenegro, which includes certain small tributaries in the Bay of Kotor and the Lake Bileć basin, belongs to the Dalmatian Ecoregion whose eastern border lies near the town of Budva.
The Southeastern Adriatic Ecoregion in Montenegro includes the southern part of the Adriatic Sea basin, i.e., the Lake Skadar/Shkodra basin and the River Bojana/Buna, as well as the River Željeznica, a small tributary running into the Adriatic Sea. Moreover, a small unnamed stream (under Mount Čakor) in the municipality of Plav that runs into the River Pećka Bistrica and the River Drim also belong to Southeastern Adriatic Ecoregion.
According to Pešić et al. (2020), the eastern border of the Dalmatian Ecoregion ends or overlaps with the eastern boundary of the Trebišnjica river basin (Lake Bileć) and the distribution border of Delminichthys ghetaldi, Alburnus neretvae, and Squalius svallize. On the other hand, the western, or northwestern, boundaries of the Southeastern Adriatic Ecoregion overlap with the distribution border of the fish species Pelasgus minutus.
Figure. The revised freshwater ecoregion delineations of Montenegro.(1) The Dniester-Lower Danube Ecoregion, (2) the Southeastern Adriatic Ecoregion, (3) the Dalmatian Ecoregion. From Pešić et al. (2020).
Pešić V, Grabowski M, Hadžiablahović S, Marić D, Paunović M (2020) The biodiversity and biogeographical characteristics of the River basins of Montenegro. In: Pešić V, Paunović M, Kostianoy A (eds) The rivers of Montenegro. The handbook of environmental chemistry. Springer, Berlin, Heidelberg. https://doi.org/10.1007/698_2019_414