Organic-carbon-rich sediments: benthic foraminifera as bio-indicators of depositional environments

摘要: Abstract. Fjords have been described as hotspots for carbon burial, potentially playing a key role within the cycle climate regulators over multiple timescales. Nevertheless, little is known about long-term fate of that may become stored in fjordic sediments. One the main reasons this knowledge gap arriving on seafloor is prone to post-depositional degradation, posing great challenge when trying discriminate between an actual change deposition rate and loss. In study, we evaluate use of modern benthic foraminifera bio-indicators organic content in six voes (fjords) west coast Shetland. Benthic are known be sensitive changes sediments, and their assemblage composition therefore reflect synchronous variations quantity and quality reaching seafloor. We identified four environments based relationship benthic foraminiferal assemblages sediments: (1) land-locked regions influenced by riverine and/or freshwater inputs organic matter, namely head fjords with restricted geomorphology; (2) stressed heavily stratified water column sediments rich matter low nutritional value; (3) depositional environments moderate mild or episodic current activity; (4) marginal coastal settings content, such as fjords unrestricted geomorphology. We conclude foraminifera potentially provide tool disentangle primary signals from degradation loss because of their environmental sensitivity high preservation potential the sedimentary record.