Studies of the plankton copepods also included the area of continental shelf and the Southern Adriatic deep valley with pronounced ocean characteristics. The deep waters of Southern Adriatic are inhabited by numerous species of all depth zones, with a pronounced domination of ocean forms, similar to the Mediterranean. The quantity of copepods in the area of open surface waters shows a pronounced spring maximum of abundance. The abundance of overall copepod population decreases from the shore toward the open sea of Southern Adriatic valley, with an increase of species abundance in plankton. That area is governed by stenothermal and stenohaline conditions. The Copepoda community is characterized by stenothermic and stenohaline species. Ranges of many of these are not increased horizontally toward the northern parts of Adriatic, and the individuals carried north by water currents quickly die.