Hypoxia causes preservation of labile organic matter and changes seafloor microbial community composition (Black Sea).

ABSTRACT: Bottom-water oxygen supply is a key factor governing the biogeochemistry and community composition of marine sediments. Whether it also determines carbon burial rates remains controversial. We investigated the effect of varying oxygen concentrations (170 to 0 μM O₂) on microbial remineralization of organic matter in seafloor sediments and on community diversity of the northwestern Crimean shelf break. This study shows that 50% more organic matter is preserved in surface sediments exposed to hypoxia compared to oxic bottom waters. Hypoxic conditions inhibit bioturbation and decreased remineralization rates even within short periods of a few days. These conditions led to the accumulation of threefold more phytodetritus pigments within 40 years compared to the oxic zone. Bacterial

SUBMITTER: Jessen GL 

PROVIDER: S-EPMC5302875 | biostudies-literature | 2017 Feb

REPOSITORIES: biostudies-literature