Spatial sedimentary distribution, seasonality and the characteristics of organic matter on Fernando de Noronha insular shelf

A study of the Fernando de Noronha archipelago reveals that sediment distribution on its northern insular shelf shows no seasonal variation but exhibits spatial heterogeneity, influenced by bottom morphology, sediment sources, and wave action. The sediments are predominantly calcareous fine sands (CaCO3 ≈ 88.3%) with low organic matter content (TOC < 4.29%, TP < 0.44 µmol/g), primarily of marine origin (δ13C ≈ -22.17%PDB). However, some stations show relative enrichment in organic matter (TOC > 3.0%; TN > 0.4%) linked to anthropogenic impacts and local biotic/abiotic processes, with mixed isotopic signatures (δ13C = -24.5 to -23.0%PDB). The research analyzed 19 surface sediment samples collected between December 2013 and November 2014, assessing grain size, organic matter characteristics, and geochemical ratios.

Barcellos, R. L., Oliveira, L. E. E. d., & Flores-Montes, M. d. J. (2018). Spatial sedimentary distribution, seasonality and the characteristics of organic matter on Fernando de Noronha insular shelf. Brazilian Journal of Oceanography, 66(1), 131–156. https://doi.org/10.1590/s1679-87592018146206601