The effect of salmon aquaculture on marine cobble communities in the Bay of Fundy

Abstract

The environmental impact of salmon aquaculture effluents below salmon cages and on soft-bottom benthic communities has been well studied. However, investigation of their effects outside lease sites and on hard-bottom benthic communities has been sparse. This study sampled three pairs of cobble sites in the Bay of Fundy, New Brunswick. Each pair included one site ‘near’ (294–441 m) and one ‘away’ (799–1557 m) from a salmon aquaculture lease. We used analyses of multivariate community composition, AMBI index, and pollution-tolerant indicator species Nucula proxima and Capitella capitata to determine if proximity to salmon aquaculture changed community structure and enrichment levels of ‘near’ sites. We also tested qPCR as a method for quantifying indicator invertebrates in mixed-species samples. Multivariate community composition differed between the ‘near’ and ‘away’ sites. AMBI index analysis indicated the abundance of pollution-tolerant taxa was significantly higher at ‘near’ sites. We also found qPCR has potential in quantifying indicator invertebrates.