(Science Times) AVON, Maine -- On a bright March morning, Paul Christman hiked through deep snowdrifts on the bank of Avon Valley Brook in the western Maine mountains, leading a crew wearing waders and shouldering unwieldy backpacks. One crew member carried a pack basket loaded with battered funnels crafted from stovepipes, duct tape and plumbing pipes. Another lugged a water pump. The last brought a cooler full of thousands of fertilized Atlantic salmon eggs.