Island connectivity

The mangroves of the Cananéia-Iguape Lagoon System, at the southern end of the coast of the state of São Paulo, have the presence of the grass Spartina alterniflora on their outer fringes, which plays a fundamental role in fixing sediments that could become mangrove propagation areas. Pioneers in the flooded mangrove region, Spartina holds and prepares the substrate for the seedlings of mangrove species to establish themselves. The mapping of Spartina alterniflora on the Cananéia and Comprida Islands, where these islands border the same lagoon channel, made it possible to identify the areas prone to its growth. The low energy points of the channel’s water flow proved to be favourable for the emergence of Spartina banks. The continuous exchange of sediments and nutrients in a lagoon environment rich in mangroves, combined with the great capacity of Spartina to capture and attach itself, resulted in a study of connectivity between two islands.