Scaling percentages and distributional patterns of benthic foraminifera with flux rates of organic carbon

Seafloor organic matter flux from marine primary productivity is quantified , and the range of annual flux rates is calculated and compared to the coun ts of benthic foraminifera at 382 surface sediment stations from the equato rial Guinea Basin to the Arctic Ocean. Benthic foraminifera show high variability in flux range dependent distribu tional patterns, with maximum deviations at lowest percentages. The occurre nce of a single species covers flux ranges within one to three orders of ma gnitude. Only a small number of species shows a correlation of this broad r ange of organic fluxes versus percentages in a count. For C. wuellerstorfi a functional relationship for the recalculation of flux rates from percenta ges in a count can be given within a standard deviation below 2 g organic c arbon [m(-2) yr(-1)], However, such functions have to be restricted to a sp ecific size range counted. The patterns of dominance more closely scale the environmental optimum of t he species in general. For interspecific combinations, these patterns ident ify the ranges of overlap, where it is impossible to distinguish between hi gher or lower fluxes on the basis of faunal composition. This is quantified for the co-occurrence of C. wuellerstorfi and U. peregrina near 20% for on e species, On an ocean wide scale, a number of taxa can be used to define threshold va lues for the nutritive needs of the assemblages, most pronounced within ann ual flux ranges at 2-3 g org, C [m-2], Different trophic needs of species c an be attributed to their infaunal, epibenthic, or opportunistic behavior r espectively, and examples for the flux dependent takeover in dominance are given. These quantifications may offer approximations for Aux rate dependen t faunal patterns in surface sediments and for the detection of flux rate d ependent faunal fluctuations in the Quaternary record.