Environ Pollut. 2016 Mar;210:361-70. doi: 10.1016/j.envpol.2016.01.015. Epub 2016 Jan 22.
- 1Environment
and Climate Change Canada, National Wildlife Research Centre, 1125
Colonel By Drive, Ottawa, Ontario, K1A 0H3, Canada. Electronic address:
tony777@rogers.com.
- 2University of Waterloo, Department of Biology, 200 University Ave. W., Waterloo, ON, N2L 3G1, Canada.
- 3Environment and Climate Change Canada, 115 Perimeter Rd, Saskatoon, SK, S7N 0X4, Canada.
- 4Environment and Climate Change Canada, 6 Bruce St, Mount Pearl, NL, A1N 4T3, Canada.
- 5Environment and Climate Change Canada, 1550 avenue D'Estimauville, QC, G1J 0C3, Canada.
- 6Environment and Climate Change Canada, 5421 Robertson Rd, Delta, BC, V4K 3N2, Canada.
Abstract
We
investigated mercury (Hg) concentrations in small fish (mainly yellow
perch, Perca flavescens; ∼60% of fish collected) and in blood of common
loons (Gavia immer)
that prey upon them during the breeding season on lakes in 4 large,
widely separated study areas in Canada (>13 lakes per study area;
total number of lakes = 93). Although surface sediments from lakes near a
base metal smelter in Flin Flon, Manitoba had the highest Hg
concentrations, perch and other small fish and blood of common loon
chicks sampled from these same lakes had low Hg concentrations similar
to those from uncontaminated reference lakes. Multiple regression
modeling with AIC analysis indicated that lake pH was by far the most
important single factor influencing perch Hg concentrations in lakes
across the four study areas (R(2) = 0.29). The best model was a
three-variable model (pH + alkalinity + sediment Se; Wi = 0.61,
R(2) = 0.85). A single-variable model (fish Hg) best explained
among-lake variability in loon chick blood Hg (Wi = 0.17; R(2) = 0.53).
From a toxicological risk perspective, all lakes posing a potential Hg
health risk for perch and possibly other small pelagic fish species
(where mean fish muscle Hg concentrations exceeded 2.4 μg/g dry wt.),
and for breeding common loons (where mean fish muscle Hg concentrations
exceeded 0.8 μg/g dry wt., and loon chick blood Hg exceeded 1.4 μg/g dry
wt.) had pH < 6.7 and were located in eastern Canada.
Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.
KEYWORDS:
Acidification; Common loon; Fish; Mercury; Perch; Toxicity
