Difference between revisions of "FOOD BASE"

Food Base

• 100824_AMWG Meeting- Attachment 12.a

• USGS- GCMRC Aquatic Food Base Link

• Black Flies and Midges fuel RBT growth.
• Black Flies and Midges respond positively to HFE's
• Mud Snails were introduced to the system around 1995.
• Temperatures/ TCD on Food Base: Benthic algae and invertebrates that form the fish food base are adapted to constatn, cold water temperatures. They may not be able to withstand cycling between warm and cold temperatures. (pg23)
• GCMRC scientists and their university cooperators (University of Wyoming, Idaho State University, and Loyola University, Chicago) are studying the kinds of organic matter (for example, algae and leaf litter) and invertebrate communities (for example, black flies and bloodworms (Families: Lumbricidae and Tubificidae)) in the Colorado River below Glen Canyon Dam and how the sun’s energy is captured and passed from one species to another. Collectively, organic matter and the aquatic invertebrates that consume it largely constitute the food base for fish in the Colorado River ecosystem. Current research efforts focus on the temporal patterns, multi-year trends, and factors that affect the amount and sources of food for humpback chub and rainbow trout (Oncorhynchus mykiss). This information is used to understand the role that food plays in determining the distribution, population density, and growth of these animals. A better understanding of the aquatic food web of the Colorado River will allow natural resource managers to describe the conditions that would be expected to support the Grand Canyon population of humpback chub, the economically important Lees Ferry trout fishery, and other fish species.