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QHEI Header. Standard River Code & RM Stream Name New Station ID Location Description Date Scorer Lat/Long. Substrate Metric. Substrate Metric. Identify Two Predominant Substrate Types By Amount or Function Two boxes in case one type is only dominant type (e.g., bedrock)

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  1. QHEI Header Standard River Code & RM Stream Name New Station ID Location Description Date Scorer Lat/Long

  2. Substrate Metric

  3. Substrate Metric • Identify Two Predominant Substrate Types • By Amount or Function • Two boxes in case one type is only dominant type (e.g., bedrock) • Lines after boxes for checking or estimating % of all substrate types present • Pebble count procedure provides good training for assessment of substrate

  4. Substrate Size Categories Boulder: > 10” Boulders as slabs: flat rather than round pieces Cobble: 2.5” to 10” Gravel: 1/12” to 2.5” (note wide range) Sand: gritty texture Silt: greasy texture, inorganic Muck: decayed organic material Detritus: leaves, sticks, wood Hardpan: usually clay, hard gummy surface

  5. Boulder-Cobble

  6. Clean Gravel Substrates

  7. Substrate Metric • Substrate Diversity • Number of substrate types • More substrate types = more “niches” • Many fish and macroinvertebrate species are associate with specific substrate types • Substrate Origin • Informational • From where did the substrates originate? • Bedrock, tills, alluvial sediments, colluvial sediments?

  8. Substrate Origin • Limestone: Often contains fossils, easily scratched with knife, usually bedrock or flat boulders and cobbles • Tills: Sediments deposited by glaciers; particles often rounded. Can be carried into non-glaciated areas • Wetlands: Usually organic muck and detritus • Hardpan: Clay – smooth, usually slippery • Sandstone: Contains rounded fragment of sand “cemented” together • Rip/Rap: Artificial boulders • Lacustrine: Old lake bed sediments • Shale: “Claystone,” sedimentary rock made of silt/clay, soft and cleaves easily • Coal Fines: Black fragments of coal, generally SE Ohio only

  9. Pebble Count Methodologies • Wolman Pebble Count • Zig-Zag Pebble Count • Riffle Stability Index • Others

  10. Pebble Count

  11. Pebble Count - Trends

  12. Silt Cover & Embeddedness • Pervuasiveness of silt cover & embeddedness • Smother habitats • Reduce oxygen penetration • Fines fill interstitial spaces

  13. Silt Cover

  14. Embeddedness – Side View

  15. Embeddedness • Sands, other fines cover larger substrates • “Dunes” indicate high bedload • Can often dig down to larger substrates

  16. Embeddedness - Aggradation • Import of fines > export • Results in “aggradation of sediments in riffles and pools • Symptom can be “spongy” deposits of sands and fine gravels that smother larger riffle particles

  17. Low Embeddedness: “Fish-eye View”

  18. High Embeddedness: “Fish-eye View”

  19. Substrate Embeddedness

  20. Fish IBI

  21. Substrate Metrics Strongly Correlated with IBI, Metrics • Affects overall community structure • Decrease substrate quality leads to loss of sensitive species • Decreasing substrate quality leads to increase in omnivores • Decrease substrate quality leads to decrease in many sport fish species (e.g., smallmouth bass).

  22. Substrate Score vs IBI

  23. TIVs for Substrate Score

  24. Substrate Effects: Strong on Individual Species: QHEI Substrate Score

  25. Smallmouth Bass vs QHEI Substrate

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