Large Rivers Chapter 20

Large RiversLarge RiversChapter 20Chapter 20

Large RiversLarge Rivers

Important Important longitudinal, longitudinal, horizontal, vertical horizontal, vertical interactions within interactions within riversrivers

Large RiversLarge Rivers

e.g., FPOM - fine e.g., FPOM - fine particulate organic particulate organic matter inputs from matter inputs from upstream, upstream, floodplainfloodplain

Heterotrophic ---- Heterotrophic ---- collector collector invertebrates ----- invertebrates ----- fish productionfish production

Impacted by Human Impacted by Human ModificationsModifications

Multiple-use conflictsMultiple-use conflicts Fishing, other recreationFishing, other recreation NavigationNavigation Flood controlFlood control Water sourceWater source

ImpoundmentImpoundment

Flood control, Flood control, navigation, navigation, hydropowerhydropower

Navigation/Flood Control Navigation/Flood Control AidsAids

Dikes, levees, Dikes, levees, channel channel stabilizationstabilization

Floodplain Floodplain reduction - 90% reduction - 90% in lower in lower Mississippi Mississippi RiverRiver

Boat TrafficBoat Traffic

Wave action, Wave action, turbulence, turbulence, sediment sediment suspension, suspension, erosion, erosion, dewateringdewatering

Hydropower Hydropower HydrographsHydrographs

Altered Altered seasonal, daily seasonal, daily flowsflows

Cooling WaterCooling Water

Intakes, Intakes, outflowsoutflows

Impingement, Impingement, entrainmententrainment

Heated waterHeated water

PollutionPollution

Sediment, PCBs, Sediment, PCBs, sewagesewage

Flow DiversionsFlow Diversions

Irrigation, public Irrigation, public needsneeds

The Fishery - Sport FishThe Fishery - Sport Fish

ColdCold large rivers large rivers

Salmon, troutSalmon, trout


CoolCool large rivers large rivers

Walleye, Walleye, smallmouth smallmouth bass, northern bass, northern pikepike


WarmWarm large large riversrivers

Bluegill, Bluegill, crappie, crappie, largemouth largemouth bass, catfishesbass, catfishes


Best in Best in unmodified unmodified reachesreaches

e.g., Missouri e.g., Missouri River - 2 to 2.5 X River - 2 to 2.5 X more productivemore productive

Unmodified vs. ModifiedUnmodified vs. Modified


Modified reachesModified reaches

Best in Best in tailwaterstailwaters (walleye, sauger), (walleye, sauger), main channel main channel borderborder (sunfish, (sunfish, bass, pike)bass, pike)

Modified Mississippi Modified Mississippi RiverRiver

The Fishery - The Fishery - Commercial FishCommercial Fish

Often same as Often same as sport fishsport fish

Conflict as sport Conflict as sport fishing pressure fishing pressure increasesincreases


Typical catch in Typical catch in upper upper Mississippi Mississippi RiverRiver Common carpCommon carp CatfishesCatfishes Freshwater Freshwater

drumdrum

Mississippi River CatchMississippi River Catch


Problem - Problem - benthophagic benthophagic fishfish

Uptake of Uptake of contaminants contaminants from sedimentsfrom sediments

PCBsPCBs Management Management

concernconcern

PCBs in the Mississippi PCBs in the Mississippi RiverRiver

Large Rivers Chapter 20

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