PowerPoint Presentation
Standard River Code & RMStream NameNew Station IDLocation DescriptionDateScorerLat/Long
QHEI Header
1Substrate Metric
2Identify Two Predominant Substrate TypesBy Amount or FunctionTwo boxes in case one type is only dominant type (e.g., bedrock)Lines after boxes for checking or estimating % of all substrate types presentPebble count procedure provides good training for assessment of substrate
Substrate Metric3Substrate Size CategoriesBoulder: > 10Boulders as slabs: flat rather than round piecesCobble: 2.5 to 10Gravel: 1/12 to 2.5 (note wide range)Sand: gritty textureSilt: greasy texture, inorganicMuck: decayed organic materialDetritus: leaves, sticks, woodHardpan: usually clay, hard gummy surface4Boulder-Cobble
5Clean Gravel Substrates
6Substrate DiversityNumber of substrate typesMore substrate types = more nichesMany fish and macroinvertebrate species are associate with specific substrate typesSubstrate OriginInformationalFrom where did the substrates originate?Bedrock, tills, alluvial sediments, colluvial sediments?
Substrate Metric7Substrate OriginLimestone: Often contains fossils, easily scratched with knife, usually bedrock or flat boulders and cobblesTills: Sediments deposited by glaciers; particles often rounded. Can be carried into non-glaciated areasWetlands: Usually organic muck and detritusHardpan: Clay smooth, usually slipperySandstone: Contains rounded fragment of sand cemented togetherRip/Rap: Artificial bouldersLacustrine: Old lake bed sedimentsShale: Claystone, sedimentary rock made of silt/clay, soft and cleaves easilyCoal Fines: Black fragments of coal, generally SE Ohio only8Pebble Count Methodologies
Wolman Pebble CountZig-Zag Pebble CountRiffle Stability IndexOthers9
Pebble Count10
Pebble Count - Trends11Pervuasiveness of silt cover & embeddednessSmother habitatsReduce oxygen penetrationFines fill interstitial spacesSilt Cover & Embeddedness12Silt Cover
13Embeddedness Side View
14Embeddedness
Sands, other fines cover larger substratesDunes indicate high bedloadCan often dig down to larger substrates15Embeddedness - Aggradation
Import of fines > exportResults in aggradation of sediments in riffles and poolsSymptom can be spongy deposits of sands and fine gravels that smother larger riffle particles16Low Embeddedness: Fish-eye View
High Embeddedness: Fish-eye View
Substrate Embeddedness
20
21
Fish IBI22Affects overall community structureDecrease substrate quality leads to loss of sensitive speciesDecreasing substrate quality leads to increase in omnivoresDecrease substrate quality leads to decrease in many sport fish species (e.g., smallmouth bass).Substrate Metrics Strongly Correlated with IBI, Metrics23Substrate Score vs IBI
24
TIVs for Substrate Score
Substrate Effects: Strong on Individual Species:QHEI Substrate Score26Smallmouth Bass vs QHEI Substrate
27
28
29