Controls on the standing crop of benthic foraminifera at an oceanic scale

Currently there is very little basin-scale information on patterns of standing crop in marine organisms or their structuring forces. Understanding modern patterns and controls on foraminifera is particularly critical because of their abundance and importance in benthic systems as well as their role as palaeoceanographic proxies. Here, we examine for the first time basin-scale patterns and predictors of benthic foraminiferal standing crop from shelf to abyssal deep sea in the Atlantic Ocean and adjacent seas using a large database of 967 quantitative samples. Spatial regression analyses reveal that the flux of particulate organic matter (POC) is a major control on standing crop size across all depths investigated, with increasing food supply increasing foraminiferal standing crops. Other factors also play a role. Dissolved oxygen is significant at slope depths and negatively related to standing crop. Temperature and possibly salinity are significant factors in the abyss. Dissolved silicate was important and positively related to standing crop in shelf seas, potentially indicating the importance of the nature of the organic material available. This study demonstrates that productivity is important in describing foraminiferal standing crop at a basin scale, supporting the use of paleoceanographic proxies, but also demonstrates that other environmental variables are also likely important in controlling the standing crop and should be considered in reconstruction of Earth’s past marine environment.