Intensive marine finfish aquaculture impacts community structure and metal bioaccumulation in meso-zooplankton

Abstract

Commercial aquaculture has a profound impact on coastal marine environments. Here, we investigate the spatial impact of intensive commercial finfish aquaculture on local meso-zooplankton communities and the bioaccumulation of aquaculturally-derived metals (and other elements) within zooplankton samples in the Vourlias Bay, Greece. The results indicate alterations to zooplankton community composition correlate with increased eutrophic compound concentrations in the water column in closer proximity to aquaculture stations (100-300 m from fish cages). During the summer sampling, higher concentrations of accumulated metals within zooplankton samples were found at reference stations furthest from fish cages (>1000 m). During the winter sampling, however, spatial differences in accumulated metal concentrations were limited. We suggest metals are rapidly accumulated at lower trophic levels near aquaculture stations and are then dispersed to greater distances while ascending the trophic chain. This research provides good evidence for future investigations into zooplankton as an environmental impact bioindicator for aquaculture.

Keywords: Aquaculture; Bioaccumulation; Elements; Mediterranean Sea; Trace metals; Zooplankton ecology.