One of our favourite places to find birds is in the waters and shorline in the Cowichan Bay Estuary. They seldom fail to provide shooting opportunities. Estuary facts: An estuary is a semi-enclosed coastal body of water with one or more rivers or streams flowing into it, and with a free connection to the open sea. The salinity of such areas is less than that of the open ocean but greater than that of a typical river, so organisms living in or near estuaries have made adaptations to adjust to this unique environment.