Assessment of the ecotoxicity of urban estuarine sediment using benthic and pelagic copepod bioassays.

Maria P Charry,Louis A Tremblay,Mark Costello,Vaughan Keesing

doi:10.7717/peerj.4936

Abstract

Urban estuarine sediments are sinks to a range of contaminants of anthropogenic origin, and a key challenge is to characterize the risk of these compounds to receiving environments. In this study, the toxicity of urban estuarine sediments was tested using acute and chronic bioassays in the benthic harpacticoid Quinquelaophonte sp., and in the planktonic calanoid Gladioferens pectinatus, two New Zealand copepod species. The sediment samples from the estuary tributary sites significantly impacted reproduction in Quinquelaophonte sp. However, results from one of the estuary sites were not significantly different to those from the tributaries sites, suggesting that chemicals other than trace metals, polycyclic aromatic hydrocarbons and ammonia may be the causative stressors. Sediment elutriate samples had significant effects on reproductive endpoints in G. pectinatus, and on the induction of DNA damage in cells, as shown by the comet assay. The results indicate that sediment contamination at the Ahuriri Estuary has the potential to impact biological processes of benthic and pelagic organisms. The approach used provides a standardized methodology to assess the toxicity of estuarine sediments.

Highlights

Population growth in coastal areas has resulted in the degradation of estuarine habitats and loss of biodiversity (Lotze et al, 2006; Micheli et al, 2013)
Sediment toxicity Only the zinc concentrations of the Old Tutaekuri riverbed and at the Humber Street drain sediment samples were above the ANZECC interim sediment quality guideline (ISQG) low value (Table 1)
Acenaphthylene and acenaphthene were the only Polycyclic aromatic hydrocarbons (PAHs) above the ANZECC Interim Sediment Quality Guidelines (ISQG)-low values at the Humber Estuary site (Table S1)

Summary

Introduction

Population growth in coastal areas has resulted in the degradation of estuarine habitats and loss of biodiversity (Lotze et al, 2006; Micheli et al, 2013). The growing demand for resources and services has increased the pressure for agricultural and industrial activities, and urban development (Neumann et al, 2015; van Vliet et al, 2015). Estuaries have become highly vulnerable to this pressure, due to the continuous input of municipal, agricultural and industrial runoff, storm water discharges and accidental wastewater overflows (de los Rıos et al, 2016; Risch et al, 2018; Rodrigues et al., How to cite this article Charry et al (2018), Assessment of the ecotoxicity of urban estuarine sediment using benthic and pelagic copepod bioassays. 2017; Willis et al, 2017) These stressors, added to the increase in sedimentation, have made estuaries a sink for pollutants with affinity for small particles 2012, unpublished data: report HAM2012-048, available upon request from NIWA; Vermeiren, Munoz & Ikejima, 2016)

Objectives

Methods

Results

Discussion

Conclusion