Methods to detect and monitor environmental change using indigenous species are in demand more and more each day as they become recognized as important tools in resource management and in situ monitoring (e.g., Goldberg, 1998). The benthic foraminifera continue to emerge as an important and unique type of indicator organism. As was illustrated in Chapter 3, they are abundant, provide statistically significant populations in small samples, have rapid reproductive cycles, are preserved as fossils, and have many types of applications to monitoring programs. This chapter provides a taste of some recent developments aimed at improving the utility of this group of shelled marine protozoans.

PALEOPRODUCTIVITY

Unlike the organic matter (OM) record, which essentially registers the amount of refractory organic carbon (C-org) that has bypassed the sediment/water interface, the Benthic Foraminifera Accumulation Rate (BFAR), which is defined as the number of specimens/unit area/unit time, fluctuates in relation to the downward (i.e., exported) flux of labile OM which is consumed in the benthic ecosystem. Where bottom water oxygen concentrations remain above 0.5 ml/l, the BFAR may be useful as an estimator of “export productivity” (Jorissen, 1998). Relatively productive intervals are marked by opportunistic faunae that are able to produce high numbers of offspring per gram of labile OM arriving at the seafloor. For example, phytodetritus flux (= labile OM) has been shown to trigger the rapid opportunistic reproduction of some shallow infaunal taxa (Textularia kattegantensis, Fursenkoina sp.) in Sagami Bay, Japan (Kitazato et al., 1998).