Pearl aquaculture—profitable environmental remediation?

• Published in: The Science of the total environment Vol. 319; no. 1; pp. 27 - 37
• Main Authors: Gifford, S., Dunstan, R.H., O'Connor, W., Roberts, T., Toia, R.
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier B.V 05.02.2004; Elsevier Science
• Subjects: Animal aquaculture; Animal productions; Animals; Applied sciences; Aquaculture - economics; Bioaccumulation; Biological and medical sciences; Biological treatment of waters; Bioremediation; Biotechnology; Bivalvia; Brackish; Environment and pollution; Eutrophication; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Heavy metals; Hydrocarbons; Industrial applications and implications. Economical aspects; Invertebrate aquaculture; Marine; Metals, Heavy - pharmacokinetics; Mollusca; Natural water pollution; Nitrogen - metabolism; Ostreidae; Ostreidae - metabolism; Ostreoida; Pinctada; Pollutant cycling; Pollution; Seawaters, estuaries; Water Pollutants - pharmacokinetics; Water Pollution - prevention & control; Water quality; Water treatment and pollution; Pollutant cycling; Pinctada; Bioaccumulation; Water quality; Hydrocarbons; Bioremediation; Heavy metals; Eutrophication; Microbiology; Oyster farming; Coastal zone; Marine environment; Decontamination; Bivalvia; Site selection; Ecosystem; Pathogenic; Organic compounds; Seawater; Hydrocarbon; Pesticides; Nitrogen; Heavy metal; Pearl; Environment impact; Nutrient; Water pollution; Invertebrata; Mollusca; Biological accumulation; Aquaculture
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/S0048-9697(03)00437-6

Bivalve molluscs are filter feeders, with pearl oysters able to filter water at rates up to 25 l h −1 g −1 of dry wt. tissue. Since this process leads to rapid bioaccumulation of recalcitrant pollutants such as heavy metals, organochlorine pesticides and hydrocarbons from impacted sites, it has prompted the widespread use of molluscs as biomonitors to quantify levels of marine pollution. This paper proposes pearl oyster deployment as a novel bioremediation technology for impacted sites to remove toxic contaminants, reduce nutrient loads and lower concentrations of microbial pathogens. Estimates extrapolated from the literature suggest that a modest pearl oyster farm of 100 t oyster material per year could remove 300 kg heavy metals plus 24 kg of organic contaminants via deposition into the tissue and shell. Furthermore, it was estimated that up to 19 kg of nitrogen may be removed from the coastal ecosystem per tonne of pearl oyster harvested. Pearl oysters are also likely to filter substantial amounts of sewage associated microbial pathogens from the water column. Method of cultivation and site selection are the key to minimising negative environmental impacts of bivalve cultivation. Deployment of oysters at sites with high nutrient and contaminant loadings would be advantageous, as these compounds would be removed from the ecosystem whilst generating a value-added product. Future potential may exist for harvesting bio-concentrated elements for commercial production.