The Bothnian Sea is a northern extension of the Baltic Sea, located between Finland and Sweden. It is characterized by its brackish water, which is a mix of saltwater and freshwater, and is home to various marine species. The sea is relatively shallow, with an average depth of about 50 meters, making it an important area for fishing and shipping activities. The Bothnian Sea is bordered by several significant cities, including Oulu in Finland and Umeå in Sweden. It features numerous islands and archipelagos, providing habitats for diverse wildlife. The sea plays a crucial role in the local economy and is vital for transportation and tourism in the region.