Measures of biological activity included effects on oxidationreduction conditions, pore and burrow water nutrient concentrations, subsurface oxygen concentrations, and relationships to benthic productivity. Trophic relationships were evaluated from stomach content analyses and carbon ratio studies, as well as analyses of thalassinid fecal pellets and microbial flora of surrounding sediments. Seasonality of recruitment and growth naturally alter density and biomass distributions in these populations. Size classes vary areally within intertidal and shallow subtidal habitats. Restoration of populations proceeds by planktonic recruitment and relocations of burrowed postlarval populations.
Population densities reflect subterranean burrow wall surface areas and burrow water volumes.
Ventilatory irrigation of reduced sediments modulates movement of nutrients in expelled burrow waters. Substrate and nutrient effects are potential determinants of productivity for benthic and water column microbiota. Physical studies of burrows have elucidated relationships between animal size and burrow physiography which, together with data on burrow densities and population size structure, allow extrapolation of burrow effects across large areas of habitat. Likewise, measurements of bioturbation rates by individual animals have facilitated estimates of sediment overturn by the overall populations, giving insight to overall impacts of their dominance in the infaunal assemblage and their conveyer-like effect on the vertical redistribution of sediments, nutrients, and microflora. Measurements of subsurface oxygen levels, redox conditions, and nutrient contents of burrow and pore waters have in turn quantified impacts of these populations on cycling of nutrients between benthic sediments and the water column, and have suggested possible relationships to productivity of benthic microflora of shallow sediments and burrow walls.