Presentation on theme: "Clearwater River Habitat/Bioassessment By Corey Hanson Water Quality Coordinator Red Lake Watershed District."— Presentation transcript:
Clearwater River Habitat/Bioassessment By Corey Hanson Water Quality Coordinator Red Lake Watershed District
Clearwater River Habitat/Bioassessment The Clearwater Nonpoint Study identified a need for a detailed habitat/bioassessment on the Clearwater River Sampling completed in August 2003 Index of Biotic Integrity (IBI) –Scores a 100 meter reach of a river based upon a set of standardized metrics –Different Types of IBIs Fish Macroinvertebrate Habitat
Methods Used EPA Rapid Bioassessment Protocols for Use in Streams and Wadeable Rivers: Periphyton, Benthic Macroinvertebrates, and Fish –Barbour, M.T., J.Gerritsen, B.D. Snyder, and J.B. Stribling. 1999
Site Selection More targeted than probabilistic. Sites were associated with water quality monitoring stations and access points along the river. Sites needed to be wadeable Reaches were located upstream of bridges in order to minimize (although arguably not eliminate) the influence of the bridge. 100 ft between starting point of reach and the bridge.
Site Selection For this study, tried to pick some sites that were minimally impacted, such as sites 3 and 4 in the NLF ecoregion, 6 in the NCHF ecoregion, as well as 14 and 15 in the RRV ecoregion Some sites on channelized sections of the river were picked to show the effect of channelization on habitat and aquatic life
Fish Sampling Backpack electrofishers Fish identified, weighed, and counted in the field
Fish Sampling Scores based upon –Number of natives –Number of native darters –Number of native sunfish –Number of native suckers –Number of intolerants –Percentage of tolerants –Percentage of omnivores –Percentage of insectivores –Percentage of piscivores –Percentage of hybrids –Percentage of abnormalities –catch rate
Clearwater River Habitat/Bioassessment Macroinvertebrates D-Frame Nets Same area sampled at each site (# of jabs) Habitat types sampled proportionally –Riffles –Woody Debris –Vegetation Samples preserved in 99% Isopropyl Alcohol Sorted, Counted, Identified
Clearwater River Habitat/Bioassessment Habitat Assessment –Scores based on 10 metrics Epifaunal substrate Embeddedness Velocity/depth regime sediment depostion channel flow status channel alteration frequency of riffles or bends bank stability vegetative protection riparian vegetative zone width
Physical Characterization Watershed Features –Predominant land use, NPS pollution, local erosion Riparian Vegetation In-stream Features –Reach length, width, area, depth, velocity, canopy Large Woody Debris (cubic meters) Aquatic Vegetation Water Quality –Temp, Cond, Do, pH, Turbidity, odors, oils Sediment/Substrate –Odors, deposits, oils, inorganic and organic components
Clearwater River Habitat/Bioassessment – Zooplankton Sampling Plankton Net Preserved with 99% Isopropyl Alcohol Analyzed by MNDNR Aquatic Invertebrate Biology Lab
Clearwater River Habitat/Bioassessment – Vegetation Mapping
Positive and Negative aspects of Methods Used Positives –Standard –Available, easy to understand –Results comparable if same methods are used –Repeatable – sites are easy to locate Negatives –Habitat assessment open to subjectivity, personal judgements on %’s –Subsampling of macroinvertebrates can exclude species that don’t occur in abundance such as Nepidae and Belostomatidae –Metrics used may differ among IBI studies –Differing techniques of samplers could effect results
Reference Condition Discussion The presence of a bridge may technically rule out the use of any of our sites as reference sites, but the data can be used to find areas in which reference sites may be found (upstream of reaches that scored well in this study) There were some reaches where the bridge downstream of the reach was the only anthropogenic factor “impacting” the stream Is there an acceptable buffer between a monitored reach and impoundments, bridge areas, and large tributary confluences? Do bridges affect some IBI types more than others (fish more than macroinvertebrates and habitat)?
The End Corey Hanson Water Quality Coordinator Red Lake Watershed District 218-681-5800 email@example.com