173 Journal of Foraminiferal Research, v. 29, no. 3, p. 173–185, July 1999 SCALING PERCENTAGES AND DISTRIBUTIONAL PATTERNS OF BENTHIC FORAMINIFERA WITH FLUX RATES OF ORGANIC CARBON ALEXANDER VOLKER ALTENBACH 1 ,UWE PFLAUMANN 2 ,RALF SCHIEBEL 3 ,ANDREA THIES 2 , SVEN TIMM 2 AND MARTIN TRAUTH 4 ABSTRACT Seafloor organic matter flux from marine primary productivity is quantified, and the range of annual flux rates is calculated and compared to the counts of benthic foraminifera at 382 surface sediment stations from the equatorial Guinea Basin to the Arctic Ocean. Benthic foraminifera show high variability in flux range dependent distributional patterns, with maximum deviations at lowest percentages. The occurrence of a single species covers flux ranges within one to three or- ders of magnitude. Only a small number of species shows a correlation of this broad range of organic fluxes versus percentages in a count. For C. wuellerstorfi a functional relationship for the recalculation of flux rates from per- centages in a count can be given within a standard de- viation below 2 g organic carbon [m 22 yr 21 ]. However, such functions have to be restricted to a specific size range counted. The patterns of dominance more closely scale the en- vironmental optimum of the species in general. For in- terspecific combinations, these patterns identify the ranges of overlap, where it is impossible to distinguish between higher 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 one spe- cies. On an ocean wide scale, a number of taxa can be used to define threshold values for the nutritive needs of the assemblages, most pronounced within annual flux ranges at 2–3 g org. C [m 22 ]. Different trophic needs of species can be attributed to their infaunal, epibenthic, or op- portunistic behavior respectively, and examples for the flux dependent takeover in dominance are given. These quantifications may offer approximations for flux rate dependent faunal patterns in surface sediments and for the detection of flux rate dependent faunal fluctuations in the Quaternary record. INTRODUCTION One of the pioneering works on food-related patterns and morphotypes in foraminifera was carried out by Seiglie (1968), however the theme took on a new meaning with observations on Uvigerina peregrina (e.g., Lutze, 1980, Miller and Lohmann, 1982). Numerous subsequent publi- cations reported observations on foraminiferal species cor- related with high amounts of organic carbon or other high 1 Inst. Paleontology, Richard-Wagner-Str. 10, D-80333 Munich, Ger- many. 2 Geol. Paleont. Inst., Olshausenstr. 40, 24118 Kiel, Germany. 3 Geol. Paleont. Inst., Siegwartstr. 10, D-72076 Tu ¨bingen, Germany. 4 Inst. f. Geowissenschaften, Postfach 601553, D-14415 Potsdam, Germany. productivity markers in surface sediments as well as in core samples. During the plenary session on paleoproductivity reconstructions at the IXth Congress of the R.C.M.N.S (Re- gional Committee on Mediterranean Neogene Stratigraphy) at Barcelona/Spain, Hans Schrader identified the main prob- lem that developed from these studies: as long as we only distinguish between ‘‘higher’’ or ‘‘lower’’ productivity, without calibrating productivity by numbers, observations are not comparable and remain descriptive. Local trophic resources are provided by the input of ter- rigenous matter (river mouths, etc.), submarine volcanic vents (black smokers) and the escape of lithogenic or bio- genic gas from the sediment (cold seeps). Pelagic input, however, dominates the input of organic matter in the deep sea by far (Sarnthein and others 1988, 1992; Asper and oth- ers 1992). Most benthic food chains are ultimately depen- dent on primary productivity and the resulting flux rates of organic matter to the seafloor (Graf 1989a, b; Gooday and others 1992). For example, biomass formation of marine benthic bacteria, as a valuable trophic source for foraminif- era, is strongly influenced by the flux rate of organic matter derived form primary productivity; the influence of water depth or the long-term stable concentration of organic car- bon in the sediment is low (Deming and Yager 1992; see also Gooday and Turley 1990). During the last decade, primary productivity values and resulting flux rates of organic carbon have been used as a quantitative measure of food supply to benthic foraminifera (Altenbach 1988, Altenbach and Sarnthein 1988, Loubere 1996, Schmiedel and others 1997). The link between the distribution of foraminiferal species and the organic carbon flux is recognized for several assemblages of the Atlantic Ocean (for discussion see Sarnthein and Altenbach 1995, Schmiedel and others 1997, Fariduddin an Loubere 1997). In the present study, we focus on the influence of flux rates on the abundance of foraminiferal species in general. Our data base is derived from the ‘NOSOFO’—working group (North to South Atlantic Ocean Foraminiferal Tran- sects) of G. F. Lutze at Kiel University. Co-workers adopted the taxonomy of Lutze (1980) and Lutze and Coulbourn (1984). New taxa were discussed within the group, ontogeny and variability of species were documented, keeping the tax- onomic concept well-defined. Over more than 2 decades a data set was compiled of percentages and standing stocks per 10cm 22 for 474 taxa in 382 surface samples. From glob- al maps of surface productivity and empiric flux rate equa- tions, the seafloor organic flux for these stations were cal- culated. This provides a data set of more than 20,000 species occurrences related to local food input at the sea floor de- rived from the surface waters. These compilations were named ‘Lutze-Tables’ within the working group.