The Rio Negro-Rio San Sun mangroves ecoregion covers a series of small of discontinuous mangrove forests on the Caribbean Sea coast of Costa Rica, from a small portion inside the border with Nicaragua in the west to the border with Panama in the east. The coast on this stretch is a flat, alluvial plain, and mangroves are only a small part of a diverse patchwork of local habitats including swamps, mixed rainforests, coastal lagoons, sea grass beds, and sandy beaches. Much of the territory is "blackwater river" in character - slow-moving channels in wooded swamps with water stained by decayed matter. These mangroves are periodically damaged by hurricanes, such as in 1988 from Hurricane Joan, but are able to regenerate.