Measuring flow rate and and stream height reveals how water moves through the landscape. Researchers are also tracking stream sediment loads using the next generation of computerized water-sampling devices. Arne Skaugset’s water-quality lab analyzes more than 2,000 samples per year from the Hinkle Creek, Trask, Alsea and Oak Creek (near Corvallis) watersheds.
Aquatic insects serve as water-quality indicators and as food for fish and other animals. Judith Li, retired professor of fish and wildlife, and two research assistants, Bill Gerth and Richard van Driesche, are evaluating insect populations and life-cycle patterns. Pre-harvest monitoring reveals a stream ecosystem that is “in pretty good shape,” says Gerth. Adds Li, “After comparing the first samples post-harvest, we may be observing shifts in patterns of drift and emergence associated with logging.”
Steelhead and cutthroat trout are on the move, and a team led by Bob Gresswell and Doug Bateman of the U.S. Geological Survey (both have courtesy appointments at OSU) is tracking them throughout the watershed. PIT (Passive Integrated Transponder) tags inserted into almost 2,000 fish make them register like groceries at the checkout counter every time they pass one of 30 electronic gates. The tag “allows us to see without really harassing the fish, whether they are selecting different kinds of habitat,” says Bateman.
Pacific giant salamanders are the most abundant amphibian species in Hinkle Creek streams. Working with John Hayes of the University of Florida and Mike Adams of the U.S. Geological Survey, Ph.D. student Niels Leuthold in the Department of Forest Science has been surveying in both the north and south forks to determine occupancy rates. By combining results of hydrology, insect and fish studies, researchers hope to resolve questions about the impact of harvesting on amphibians.