Friday, January 15, 2016

Impact assessments with DNA Barcoding

Mining operations are supposed to track the impact of their activities on biodiversity and demonstrate the effectiveness of their site restoration programs. As soon as profitable mining comes to an end it is the responsibility of the mining company to recreate conditions allowing biota to develop on previously mined substrate to function within a natural, self-sustaining ecosystem. 

In reality however, mine sites often leave a legacy, including perpetually altered plant communities elevated contaminants in surface and groundwater, thin, compact soils, altered soil function, and magnification of contaminants within the food chain .

Government regulations on mining operations usually set guidelines for such reclamation projects but such regulations do not exist in every country. In fact I think it is fair to say that only a minority of countries have sufficient legislation in place. But even if they are in place we know little about the ideal way to properly restore former mining sites:

Despite pervasive efforts to meet and improve upon regulatory guidelines for ecosystem services at previously mined sites, there is a large degree of uncertainty in mine land restoration. Consistent application of revegetation,soil amendments, and regrading treatments can lead to very different results, even on the same site. 

There are many potential reasons for this. The authors of a new review published in the journal Restoration Ecology e.g. list variability in starting conditions, slope, aspect, and many hitherto unmeasured or insufficiently measured factors. The latter includes measures of local biodiversity which will be at the end of the day one key measure of how well a site has been restored.

Our institute has partnered with the mining company New Gold Inc. to explore the potential of DNA Barcoding for expediting environmental impact assessments. My colleagues here conducted a pilot study at New Gold’s New Afton site near Kamloops, BC. It investigated the addition of mass arthropod sampling and DNA Barcoding to evaluate the success of site remediation efforts. The pilot program involved four sites: two grassland sites (disturbed and undisturbed) and two wetland sites (disturbed and undisturbed). Between 294 and 5,560 individual invertebrates were captured in Malaise traps each week, and 51,264 specimens were identified representing 3,956 species.

The volume of taxonomic and functional data collected for arthropods at the New Afton site is unprecedented for the mining industry, owing to the successful application of DNA Barcoding. New Afton managers intend to continue monitoring with this approach on a 4–5 year time scale. Such baseline data will provide a comprehensive understanding of the trajectory arthropod communities take as this mine site develops and is reclaimed.

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