Microsoft PowerPoint - Habitatslidestoweb [Compatibility Mode]Goals of SHM
To restore, protect, or improve stream habitat so that diverse natural habitats, coadapted populations, critical refugia, and natural ecosystem processes are
maintained in the face of human activities.
Unsuitable Flow
Unstable Streambanks
They are just plain, UGLY
Beaver Dam
Vannote et. al 1980 RCC
Ecosystem View of Stream
Uniform channel lacks pools, riffles, and boulders or log jams.
Straightening, widening, or deepening the stream channel.
Instream obstructions are typically removed to increase channel capacity.
Channelization – WHY?
removing bends in a river
Remedies
Revegetation, revetments made of trees and brush, rootwad installations, bank stabilization
Deflector Placement
Problem: Woody Debris Removal
Woody debris accumulates naturally in streams and plays important roles in stream mechanics and fish habitat.
Removal of Woody Debris
Remedies
Can increase stream stability and create fish cover
Problem: Fish Migration Barriers
Roadway culverts often hinder passage unless they are installed to meet special criteria for the fish involved.
Improperly installed culverts can block fish passage: (A) water velocity too great, (B) water in culvert too shallow, (C) no resting pool below culvert, and (D) jump too high.
Problem: Fish Migration Barriers
Dams are common barriers. Many now contain fish ways that allow passage
through turbines, spillways, and conduits upstream.
Downstream passage however is limited some do guide fish to safe outlets.
Remedies
Fishway and culvert design –understand the behavior and swimming capacity of fishes Work with hydraulic engineers who know
how to apply fluvial mechanics. Design should facilitate passage of all
migratory species, operate at all water levels, be navigable without undue stress, pass fish without delay.
Conclusion
To successfully manage stream habitat a biologist must have a working knowledge of: