Sedimentation in the adjacencies of a southwestern Atlantic giant carbonate ridge

Abstract

The continental margin off the southeastern Brazilian coast is punctuated by a series of geological-geomorphological features, such as subsurface saline diapirs and pockmarks at the seafloor interface, which evidence the abundant presence of oil and gas in the region. In several of these sites, hydrocarbons can be naturally released into the water column, areas are cold seep areas. These are marked by the presence of oil- and gas-dependent ecosystems, where specific organisms are able to fix carbon from hydrocarbon chemosynthesis. In addition, light hydrocarbon fluid flow through the sediment may build up authigenic carbonates that can be further colonized by cold-water corals, generating large carbonate mounds over geological time, normally positioned at the border of these pockmark features. The present work reports on a multidisciplinary oceanographic cruise carried out in the Santos Basin, SW Atlantic, to seek, map, and collect geological, chemical, and biological data from different deep-sea habitats. The cruise occurred in November 2019 on the R/V Alpha Crucis of the Oceanographic Institute of the University of São Paulo (IOUSP). We intended to discover and detail different geomorphological features, characterize free-living and symbiotic microorganisms, determine the chemosynthetic rates in relation to heterotrophic microbial production, and characterize the fauna and study their ecological and evolutionary links within and across ocean basins. All discoveries made during the cruise and their respective results will be presented separately in several papers that comprise this special volume.

Predicting large-scale spatial patterns of marine meiofauna: implications for environmental monitoring

“…Moreover, in comparison with traditional statistics, when a large amount of information is available, ML algorithms can better handle some of the shortcomings typically faced by large-scale studies, such as unbalanced designs, covariate effects, missing data, non-linearity, among others . The area under study, Predicting spatial patterns of marine meiofauna Gallucci et al the Santos Basin, shows increasing industrial activities related to oil and gas exploration from its coast to the deep sea (Perez et al, 2020;ANP, 2021;Sumida et al, 2022;Moreira, et al, 2023). Such routine activities may cause a variety of disturbances to the soft-sediment environment, which may have detrimental effects on benthic communities (Netto et al, 2010;Ellis et al, 2012;Washburn et al, 2016;De Léo et al, 2020).…”