Metal dispersion resulting from mining activities in coastal environments: a pathways approach

Oceanography
By:

Links

Abstract

Acid rock drainage (ARD) and disposal of tailings that result from mining activities impact coastal areas in many countries. The dispersion of metals from mine sites that are both proximal and distal to the shoreline can be examined using a pathways approach in which physical and chemical processes guide metal transport in the continuum from sources (sulfide minerals) to bioreceptors (marine biota). Large amounts of metals can be physically transported to the coastal environment by intentional or accidental release of sulfide-bearing mine tailings. Oxidation of sulfide minerals results in elevated dissolved metal concentrations in surface waters on land (producing ARD) and in pore waters of submarine tailings. Changes in pH, adsorption by insoluble secondary minerals (e.g., Fe oxyhydroxides), and precipitation of soluble salts (e.g., sulfates) affect dissolved metal fluxes. Evidence for bioaccumulation includes anomalous metal concentrations in bivalves and reef corals, and overlapping Pb isotope ratios for sulfides, shellfish, and seaweed in contaminated environments. Although bioavailability and potential toxicity are, to a large extent, functions of metal speciation, specific uptake pathways, such as adsorption from solution and ingestion of particles, also play important roles. Recent emphasis on broader ecological impacts has led to complementary methodologies involving laboratory toxicity tests and field studies of species richness and diversity.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Metal dispersion resulting from mining activities in coastal environments: a pathways approach
Series title Oceanography
DOI 10.5670/oceanog.2012.53
Volume 25
Issue 2
Year Published 2012
Language English
Publisher American Society of Limnology and Oceanography
Publisher location Waco, TX
Description 14 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Oceanography
First page 170
Last page 183