The strait connects the Gulf of Riga to the open Baltic Sea. It comprises the coastal waters lying between Ovisi village and Cape Kolka, and extending from the shore of Kurzeme county to the offshore border with Estonia. Sand and gravel are the main bottom sediments. The benthic fauna is dominated by shellfish Macoma. The main marine-traffic routes from the Baltic Sea to Estonian and Latvian ports in the Gulf of Riga pass through the strait.
The strait supports internationally important concentrations of several seabirds in winter, e.g. Gavia stellata, G. arctica, Clangula hyemalis, Melanitta fusca and Cepphus grylle. There are also large concentrations of Mergus serrator and M. merganser. Species of global conservation concern that do not meet IBA criteria: Haliaeetus albicilla (wintering).
BirdLife International (2019) Important Bird Areas factsheet: Irbe strait. Downloaded from http://www.birdlife.org on 10/12/2019.