Wolves on Isle Royale declined 21 percent over the past year due in part to "toxic" inbreeding and battles between packs, while moose on the island continue to feel the effects of a warming climate. That's according to a report released Wednesday from the 52nd annual study of the predator-prey relationship between wolves and moose on the big Lake Superior island. Wolves dropped from 24 in 2009 to 19 this year, and two of the island's four wolf packs have disappeared. Researchers Rolf Peterson and John Vucetich, Michigan Technological University biologists, said the extinction of two packs f
The amount of toxic mercury in Minnesota walleye and northern pike has been going up since the mid 1990s, the Minnesota Pollution Control Agency reported Tuesday. The unexpected increase in mercury was found in an analysis of 25 years of fish from 825 Minnesota lakes by the PCA and published last week in the journal Environmental Science & Technology. The increase surprised scientists because mercury levels in fish had been slowly but steadily declining in recent decades. "It's surprising.
Cutting small trees and brush for energy can be done without harming Minnesota's northern forests, but the cost to do the work may be more than the profit. That's the finding of the first comprehensive study of the environmental effects and economics of cutting so-called woody biomass. Researchers looked at nine plots on the Superior National Forest before and after loggers cut the wood -- brush and small trees ignored by paper or boards.