Kyoto accord signals death knell for dinosaur era fish in Canada

Sturgeon population decline attributed to global warming. Just read the headlines, it says it all. Don't bother with the paragraphs in the article that say things like "It's a big problem because hydro-electric dams are primarily built on good spawning sites or nursery areas where the fish feed. It's going to be an issue in (the provinces of) Manitoba and Ontario where they're now looking at rivers where before they weren't going to have hydro-electric dams," century ago, Canadian fishermen netted millions of kilograms of lake sturgeon each year, stacking them like logs on lakeshores. But, sightings of them nowadays are rare enough to make newspaper headlines and scientists estimate fewer than 1,000 are left in western Canadian rivers and lakes -- equal to the remaining number of plains bison that were once a symbol of Canada's vast prairies.

Changing habitat and overfishing the habitat in the past had nothing to do with it, then why the worry about adding new hydroelectric dams?