Carbon and Nitrogen Uptake of Calcareous Benthic Foraminifera along a Depth-Related Oxygen Gradient in the OMZ of the Arabian Sea

摘要: Foraminifera are an important faunal element of the benthos in oxygen-depleted settings such as Oxygen Minimum Zones (OMZs) where they can play a relevant role processing phytodetritus. We investigated uptake phytodetritus (labeled with 13C and 15N) by cal-careous foraminifera 0-1 cm sediment horizon under different oxygen concentrations within OMZ eastern Arabian Sea. The situ tracer experiments were carried out along depth transect on Indian margin over period 4 to 10 days. phy-todetrital carbon days all species shows that is rele-vant food source for sediments. decrease total from 540 1100 m suggests higher demand low-oxygen core region or less competition macrofauna. Especially Uvigerinids showed high phytodetrital at lowest oxygenated site. Variation ratio nitrogen between sites indicates foraminiferal use be decoupled nutritional demands found spe-cies. Lower could hint greater storage food-based nitrogen, ingestion hosting bacteria almost anoxic condi-tions. Shifts assemblage structure (controlled availabil-ity) presence other benthic organisms account observed changes pro-cessing habitats. dominate short-term but lower bounda-ry biological interactions distribution foraminif-era change levels.