That's a difficult thing to translate into a specific percentage. I've been working on environmental issues in the Midwest and on the Great Lakes for 40 years, and I think this is one of the biggest challenges. Frankly, it is a bit of a long shot that there would be the broad public support to make this happen. However, the more I've gotten into this issue, working with the Great Lakes Commission, and doing this work with a consulting and engineering firm, it really does show that it's feasible to do it.
The technology for the barriers themselves is really not terribly complicated. The real issue is the cost and whether or not the benefits associated with stopping the movement of invasive species in both directions can justify that kind of cost. I think it's always difficult with things of an environmental nature, where a lot of the benefits are really long term and a little harder to quantify than the short-term costs associated with the construction.
The cost figures associated with this are really spread out over a 50-year period. They include capital costs and operational and maintenance costs. The one that appears to be most viable is in the $4-billion to $5-billion range, which is a huge amount of money. If you look just at the value of the Great Lakes fishery, which has been documented in the $7-billion range...and you don't know for sure if this would wipe out the whole fishery or do severe damage, though it probably would do a lot of damage.
The other costs that can be avoided by stopping the flow of invasive species are the costs incurred to deal with the invasive species once they get to some location. The Canadian government, I'm very pleased to see, has recently made a commitment for $17 million to deal with Asian carp. The U.S., by the end of next year, I think will have invested over $80 million just to try to stop the Asian carp.
It's the kind of thing where, whether you're looking at zebra mussels or sea lampreys, at over $20 million a year that our two governments are spending together, a lot of very major costs are imposed. My sense is that more work needs to be done on the cost-benefit analysis side of things. One of the things we hope to do in the next stage of this work is to be able to document that more.
So I am convinced that this case can be made, and I am convinced that this is the kind of thing that the public will support, but because of the large dollar figure it will take some more time.