**5. Case study: continental slope of the Campos Basin (SE, Brazil)**

The Campos Basin is located between latitudes 21°S and 23°S in the southwestern margin of the South Atlantic Ocean (**Figure 5**). It ranges from the coastal plain to the São Paulo Plateau, the outer boundary of the salt tectonic coinciding with the boundary between continental and oceanic crusts [72]. The continental slope displays a convex profile to the north and a concave one to the south, and it is cut by several canyons, such as the São Tomé, Itapemirim, Grussaí, and Almirante Câmara [72]. The Campos Basin is considered a meso-oligotrophic system with oxygenated bottom water [73].

In Campos Basin, the oil exploration activities began in 1976, with the first maritime drilling occurring at 100 m of water depth. In 1999, exploration and production of hydrocarbons in deep waters (below 2000 m of depth) started in the Campos Basin. About 65% of hydrocarbon exploration and production activities are concentrated in marine areas deeper than 400 m [74].

The first initiative to evaluate the environmental conditions of the Campos Basin occurred in the end of 1980s, through a partnership between the Fundação de Estudos e Pesquisas Aquáticas (FUNDESPA), University of São Paulo, and Petróleo Brasileiro S/A (PETROBRAS). Regrettably, the data obtained were not widely disseminated through scientific publications [74].

From this on, other projects were executed in the Campos Basin, such as "Campos Basin Deep-sea Environmental Program" (Oceanprof) and

#### **Figure 5.**

*Location of Campos Basin in the Southwest Atlantic Ocean and sampling sites of the study area (Oceanprof and Habitats project): red circle (station in the Almirante Câmara canyon); and blue circle (station in the Almirante Câmara canyon).* 

 "Environmental Heterogeneity of the Campos Basin" (Habitats) projects. These projects had a multidisciplinary goal: geology and meteoceanography; organic and inorganic components of water and sediment; and the distribution and composition of biota [73, 74].
