Abundance, biomass, and productivity of invertebrate hyperbenthos in a temperate saltmarsh creek system

Abstract

The hyperbenthos of two saltmarsh creeks at Bull Island, Dublin, Ireland was sampled to quantify its contribution to the larger trophic system of the lagoon. The brown shrimp Crangon crangon (L.) dominated in terms of both abundance and biomass. All species displayed marked seasonal and spatial variability which was reflected in the estimates for production, and especially in the vales for incremental change in biomass (δB) and mortality (M). The major contributions to production were by C. crangon and the shore crab Carcinus maenas, (L.) and to a lesser extent by Palaeomonetes varians (Leach) although the actual proportions varied according to the method used to calculate production. Total system production by the hyperbenthos in the creeks was around 20 kJ m−2 y−1. The contribution of hyperbenthic production was negligible in terms of overall system energy transfer to Dublin Bay, but it may play a crucial role in the saltmarsh creeks’ nursery function and trophic transfers.