LETTER TO THE EDITOR — Diamond project called a threat to biological diversity

I would like to answer comments made in Bud Laporte’s letter (T.N.M., Sept.

2/96) and in the editor’s note following my own letter (T.N.M., Aug. 19/96).

Regarding the problem of some of BHP’s kimberlites being harmful to fish, I refer you to an Environment Canada study entitled A Preliminary Evaluation of the Lethal and Sub-lethal Toxicities to Fish of Effluents from Diamond Exploration in the Lac de Gras Area (Harrison, et al., 1995). You are correct in stating that most of the kimberlite pipes in the Northwest Territories have been found under lakes, but the tops of these pipes are likely covered with layers of lake-bottom sediments that effectively isolate the kimberlites from the aquatic environment. The problems seem to be caused when fine particles of kimberlite become suspended in water during exploration drilling or in tailings ponds.

As for my claim that “a number of genetically distinct fish populations will be lost forever,” I was referring to fish populations that are physically isolated from the fish in other lakes. Biological diversity is measured in three ways: diversity of ecosystems, diversity of species, and diversity of genes within species. It is genetic diversity that will be lost in the Lac de Gras area through the eradication of a number of lakes on BHP’s property. Of course, there is no danger that whole species of fish will be lost as a result of the impact of BHP’s mine, but the overall genetic diversity of these species will certainly be reduced by the destruction of these lakes, with long-term implications for the ecological integrity of the region.

Given how little we know about the functions of biodiversity, it seems prudent that before allowing activities that will reduce biodiversity (the destruction of fish populations, for example), we should consider carefully whether such activities are absolutely necessary.

Chris O’Brien

Yellowknife, N.W.T.