Spatial distribution of organic matter in the surface sediments of Ubatuba Bay (Southeastern - Brazil)

Abstract

Analyses of organic matter content, organic carbon, nitrogen, sulfur and granulometric variables were performed on 101 surface sediment samples from Ubatuba Bay in order to investigate the spatial distribution of organic matter, its origin and the relationships among its components. The samples were obtained with a manual corer, from water depths between 1 and 15m during 5 cruises of the R/V ''Veliger II'', two months apart. Pearson correlation, regression and Principal Component Analysis (PCA) statistical methods were used to analyze the data. Strong correlations between organic matter and fine sediment fractions were obtained. The PCA revealed at least two main sample groups that reflect the different environmental conditions prevalent in the bay. There is a simple linear relationship between organic carbon content and the organic matter content determined by the calcination technique. Taking into account that the analysis of organic matter content is less expensive and less time consuming than the analysis of organic carbon, the present method of estimation can be useful when fast evaluation of the organic carbon content is needed for samples from similar environments.

Spatial distribution and sources of organic carbon in the surface sediment of Bosten Lake, China

“…The magnitude of TOC in surface sediment may depend on many factors, including column water productivity, terrestrial inputs of organic materials, properties of sediment, and rate of microbial activity (Burone et al, 2003;Gireeshkumar et al, 2013). Among them, contributions of autochthonous and allochthonous sources have direct impacts on the spatial dis-tribution, which varies largely across regions (Bechtel and Schubert, 2009;Anderson et al, 2009), partly due to differences in lake productivity and morphology (Barnes and Barnes, 1978).…”

On the parameterization of biological influences on offshore sand wave dynamics

“…E. cordatum is regarded as a nonselective deposit feeder (Lohrer et al 2005). However, fine particles which have a higher relative surface area and a higher organic content than coarse particles (Burone et al 2003) have a higher probability of being ingested and brought downward than coarse particles (Cramer et al 1991). This causes the heterogeneous sediment distribution in the top centimeters of the bed.…”

Organic Matter Source in the Freshwater Tropical Lakes of Southern India

“…Lake floor sediments play a significant role as a trap and offer a surface for sediment deposition. They act as a natural regulator for biological processes in the lakes 3,4 . They are also a source of nutrients to the water column that lead to benthic-pelagic mixture, which influences the principal productivity 3,4 .…”

“…They act as a natural regulator for biological processes in the lakes 3,4 . They are also a source of nutrients to the water column that lead to benthic-pelagic mixture, which influences the principal productivity 3,4 . Spatial changes in the floor sediment types often carry signatures of variations in the hydrological processes that operate within the lakes and the local sediment sources 5,6 .…”