Burial of mangroves by mobile dunes: a climate change threat in semiarid coasts

Abstract

In the northeastern coast of Brazil, between the states of Maranhão and Rio Grande do Norte, the semiarid climate extends to the littoral. This sector of the Brazilian coast, known as the “dune coast”, also harbours mangroves located along estuaries and coastal lagoons. At the extreme west of this sector, the semiarid conditions transits into humid equatorial climate, typical of the Amazon region. In this transition, there is located the enormous Parnaíba Delta, the largest open sea delta in the Americas, covering about 270,000 ha. The Delta is encircled by an Environmental Protection Area (EPA), a 313,809-ha federal conservation unit established in 1996 and located at 02°37’– 03°05’ S and 42°29’– 41°09’ W (Figure 1). Within the Delta, the “Reserva Extrativista (RESEX) Delta do Parnaíba” was created by the Federal Government in 2000. This 27,021-ha extractive reserve was constituted by 3,600 families of local fishermen which depend mostly on mangrove products. Uca-crab, Ucides cordatus, is the most explored resource and the RESEX has the largest concentration of crab catchers in Brazil. The EPA, apart from preserving over 100,000 ha of mangroves and associated ecosystems, protects the IUCN Red List, Red-handed Howler Monkey Alouatta belzebul; a relatively large cetacean diversity and a highly diversified avifauna, including colonies of the iconic scarlet ibis Eudocimus ruber