The environment inhabited by soft-bottom benthic infauna is an open, dynamic system consisting of biogeochemical reactants and products in a mineral matrix. Seasonality in temperature and supply of labile organic material modulate rates of microbial activity causing variation in vertical and horizontal locations of chemical strata (e.g. the sulfide containing layer). A deterministic model of sediment biogeochemical processes which considers temperature, dissolved oxygen in the overlying water, and labile organic material successfully emulated EH observations at an enriched site in the New York Bight. Using the modeled relationships, sediment biogeochemistry is interpreted as being forced by availability of labile organic material. These forces interact to present an ever changing, three-dimensional milieu of benthic animals.

Distribution of benthic animals have historically been associated with sediment type. Having evolved (or retained) anoxyphilic capabilities, the thiobios, together with the better studied ixybios, form a set of animals capable of exploiting the spectrum of environment conditions from strongly reducing to fully oxidizing. Collectively, they parallel the microbial series of anaerobic, microaerophilic and aerobic bacteria, and as the microbes, the macro-benthos affects and is affected by sediment biogeochemistry.

Total numbers of macrofaunal special at stations in the New York Bight apex were found to have a strong inverse association with surface redox potential. Nucula proxima was numerically dominant in more oxidizing conditions (EH 200 mV), where as, dominance shifted to Capitella spp. under reducing conditions (EH below 100 mV). Of the 40 most abundant macrobenthic species, half had occurrence and abundance distributions characterized by oxyphilic, with specific anoxia and sulfide tolerance appear to be strong factors in determining breadth of niche in the EH range studied. This is consistent with a biochemical mechanism, while etoxification of trace metals by solid sulfide appears not to be a factor in the study area. Field experiments on the influence of a biogeochemical product (sulfide) on larval settlement and patterns of use of habitats by Limulus polyphemus , tend to confirm the hypothesis that sediment biogeochemistry is a major factor structuring benthic communities.