Analysis of benthic invertebrate communities as a function of distance from two fish processing plant effluent discharges in New Brunswick, Canada

Abstract

Benthic invertebrate communities have been known to change due to impacts from nutrient-rich industrial outputs such as those from pulp and paper, sewage treatment plants or aquaculture. Fish processing plants have been recognized as contributors of large volumes of nutrient rich effluent to marine and estuarine environments but their effect on benthic invertebrate communities is unknown. Benthic invertebrates and sediment samples were obtained from marine sampling stations at 0, 10, 30 and 100m distance from two fish processing outfalls in Atlantic Canada. Sediment grain size, total organic carbon (TOC), ammonia, sulphide and redox as well as invertebrate abundance, density, taxa richness, Simpson’s inverse diversity index, Bray Curtis index and the AZTI marine biotic index (AMBI) were determined for all sampling sites. Results from this study illustrate that taxa richness and density significantly increased as distance from the outfall discharge increased. In our study, TOC was only significantly correlated to AMBI but not to the other benthic invertebrate assemblage descriptors calculated in this study (invertebrate density, taxa richness, Simpson’s inverse diversity). The study results suggest that taxa richness and density may be affected by the effluent from fish processing plants.