Along the coast are a series of islands that contribute to the marine diversity of their surroundings, including Ilha Grande (a UNESCO World Heritage Site, Restinga da Marambaia, the mountainous Ilhabela archipelago, and Santa Catarina Island at Florianopolis in the south of the region.

[8] The broadband anchovy (Anchoviella lepindentostole) is an important traditional fishery along São Paulo State, although unsustainable fishing practices are threatening it and other stocks like the Grey triggerfish (Balistes capriscus).

[8] Off-shore, marine diversity is increased by seasonal upwelling of nutrient-rich, cold subtropical waters from cyclonic activity of the Brazil Current.

[8] The off-shore fisheries center on trawling for shrimp, and purse seine fishing for the highly depleted sardines.

[8] Conservation threats to the ecoregion are mainly due the large urban areas along the coast (Rio de Janeiro, São Paulo), and associated industrial pollution.