The Mnazi Bay-Ruvuma Estuary Marine Park (MBREMP) was established on 1 July 2000 under Act No.

The park is in the Mtwara district of Southeast Tanzania and extends to the border with Mozambique.

The area is considered to have globally significant marine biodiversity values and covers 650 square kilometres, of which 33% is on land.

The park extends from the northern portion of the Ruvuma Estuary to Mnazi Bay, including the headland of Ras Msangamkuu.

The environment within the park includes mangroves, rocky and sandy shoreline, mudflats, salt pans, fringing coral reefs, lagoonal patch reef, seagrass beds, three islands (Namponda, Mongo and Kisiwa Kidogo) and numerous small rocky islets.