Mesocosm validation of the marine No Effect Concentration of dissolved copper derived from a species sensitivity distribution

Abstract

The Predicted No Effect Concentration (PNEC) for dissolved copper based on the species sensitivity distribution (SSD) of 24 marine single species tests was validated in marine mesocosms. To achieve this, the impact of actively maintained concentrations of dissolved copper on a marine benthic and planktonic community was studied in 18 outdoor 4.6m(3) mesocosms. Five treatment levels, ranging from 2.9 to 31μg dissolved Cu/L, were created in triplicate and maintained for 82days. Clear effects were observed on gastropod and bivalve molluscs, phytoplankton, zooplankton, sponges and sessile algae. The most sensitive biological endpoints; reproduction success of the bivalve Cerastoderma edule, copepod population development and periphyton growth were significantly affected at concentrations of 9.9μg Cu/L and higher. The No Observed Effect Concentration (NOEC) derived from this study was 5.7μg dissolved Cu/L. Taking into account the DOC concentration of the mesocosm water this NOEC is comparable to the PNEC derived from the SSD.

Applying Generic Water Quality Criteria to Cu and Zn in a Dynamic Aquatic Environment—The Case of the Brackish Water Formation Strömmen-Saltsjön

“…These PNEC or NOEC values are derived from vast datasets of the highest validity and quality in relation to available ecotoxicological reference databases. For both Cu [3] and Zn [32], additional marine mesocosm studies were performed which verify and support these values. For Zn, no marine PNEC value was derived in the risk assessment report [2].…”

“…As a result, only minor fractions of their total concentrations exist in any bioavailable form, i.e., accessible for organism uptake. Numerous studies show that when metal bioavailability is considered on a larger spatial scale in fresh-and saltwater, neither Cu nor Zn can be concluded to pose any considerable threat to the aquatic environment [1][2][3][4][5]. However, there may occasionally be exceptions due to very specific water chemistry conditions in terms of concentrations of organic matter and dissolved organic carbon (DOC), water pH and ionic strength (salinity) and/or total metal concentrations [6,7].…”

“…These values are derived from vast datasets of the highest validity and quality in relation to available ecotoxicological findings. After additional mesocosm studies [3,32] and the verification of derived PNEC values based on species sensitivity distributions (SSD), the EU has, via their Committees on Health and Environmental Risks (SCHER), accepted an assessment factor (AF) of 1 for Cu [33]. The risk assessment report of Zn [2] presents NOEC values for marine organisms spanning from 10 to 2700 µg/L dissolved Zn with the lowest marine NOEC of 10 µg/L.…”

Leaching of Metals from Steel Slag and Their Ecological Effects on a Marine Ecosystem: Validating Field Data with Mesocosm Observations

“…Chemical analyses. At weekly intervals water samples were collected for analyses of the dissolved fraction of 18 inorganic compounds (Table 1), following the method described in Foekema et al (2015). In short, 60-mL samples were collected from each mesocosm at half the water depth using a polyethylene syringe.…”