| Popis: |
We have investigated the spatial heterogeneity of continental shelf substrates in Equatorial Rio Grande do Norte, RN State, northeast Brazil, and the benthic communities of organisms associated with them. The integrated data set used in this study consists of acoustic data, remote sensing, ground truth video data, and sediment samples. Distinct geomorphic features observed include very large subaqueous dune fields, submerged beachrock ridges, coral reefs, and incised valleys. The inner-middle, and outer shelf are broadly distinguished by water depth, geomorphology and sediment characteristics. Our study indicates that the seabed features and associated grain size are responsible for the structure and composition of benthic macroinfaunal and epifaunal communities. On this equatorial tropical shelf, fine-grained sediments, within an incised shelf valley, exhibit less diverse and a less abundant macroinfauna assemblage than adjacent sandy bottoms, both bioclastic and siliciclastic, which harbor faunas of greater abundance and diversity. |
