Fish_Flow-Biology_Hypotheses

SUMMARY OF FISH - BIOLOGY HYPOTHESES - Blann, K. and E. Kendy. 2012. Developing Ecological Criteria to Support Sustainable Water Management in Minnesota. The Nature Conservancy, Minneapolis,
MN. (Appendix 3)
Fish Common Name
Longnose dace
Central stoneroller
Margined madtom
Fantail darter
Sculpin
White sucker
Shorthead redhorse
small mouth bass
Redbreast sunfish
Creek chub
River chub
brook trout
American eel
Alewife
Walleye
Scientific Name
Rhinichthys cataractae
Campostoma anomalum
Noturus insignis
Etheostoma flabellare
Catostomus commersoni
Moxostoma macrolepidotum
Micropterus dolomieui
Lepomis auritus
Semotilus atromaculatus
Nocomis micropogon
Salvelinus fontinalis
Anguilla rostrata
Alosa pseudoharengus
Guild
riffle obligate
rifle obligate
rifle obligate
rifle obligate
rifle associate
rifle associate
rifle associate
nest builder
nest builder
nest builder
nest builder
nest builder
nest builder
nest builder
nest builder
cold headwater
anadramous
anadramous
January
Reduced flows lead to loss of riffle habitat
high flow events may flush eggs
Maintain high flows for habitat maintenance
February
Loss of flushing flows reduces spawning success
March
Decreased flows during spawning reduce recruitment
Increases in high flow events flushes larva downstream
Increase in extreme low events impacts movement between habitats
Decreased flows during spawning limits recruitment
April
high flows could delay spawning
stable flows needed to maintain spawning habitat
May
Decreased low flows will reduce high velocity habitat
Dereased flow magnitude leads to decreased habitat and food availability
Extreme low flows can expose nests
Increased high flows reduces spawning success
Stable flows are needed to keep males on nest
Decreased flow magnitude reduces connectivity between pools over riffles
June
flows outside of mean reduce recruitment
July
Decreased flows during spawning limits juvenile growth
pools maintained for successful adult growth
Extreme summer low flow can negatively affect juvenile and adult growth
August
September
October
maintain longitudinal connectivity during spawning
Cue migration
Cue migration
November
December

Summary of Fish Flow-Biology Hypotheses from the following sources:
GENERAL IMPACTS:
Low Flows
Standard / Median Flows
High Flows
Floods
Flashiness
Blann, K. and E. Kendy. 2012. Developing Ecological Criteria to Support Sustainable Water Management in Minnesota. The Nature Conservancy, Minneapolis, MN. (Appendix 3)
DePhilip, M. and T. Moberg. 2010. Ecosystem Recommendations for the Susquehanna River Basin. The Nature Conservancey, Harrisburg, PA (Appendices)
DePhilip, M. 2012. Working Hypotheses developed for fishes in Ohio River basin habitats (Table 2). The Nature Conservancy, Harrisburg, PA (work in progress)
IMPACT:
Reduced
Increased
Reduced
Increased
Increased
Decreased
SOURCE:
Susquehanna EF
TNC EF Hypotheses/Ohio Basin EF/Susquehanna
Susquehanna EF
Ohio Basin EF
Ohio Basin EF
TNC EF Hypotheses
TNC EF Hypotheses /Susquehanna EF
TNC EF Hypotheses
TNC EF Hypotheses
Ohio Basin EF
TNC EF Hypotheses
TNC EF Hypotheses/Ohio Basin EF
Ohio Basin EF
Susquehanna EF
Susquehanna EF
Susquehanna EF
Ohio Basin EF/Susquehanna EF
Ohio Basin EF
Ohio Basin EF
Susquehanna EF
TNC EF Hypotheses
TNC EF Hypotheses/Ohio Basin EF/Susquehanna
TNC EF Hypotheses/Ohio Basin EF/Susquehanna
Ohio Basin EF
TNC EF Hypotheses
Susquehanna EF
Susquehanna EF
TNC EF Hypotheses
Ohio Basin EF
Ohio Basin EF
Ohio Basin EF
EK Appendix 3/Ohio Basin EF/Susquehanna EF
Ohio Basin EF
Ohio Basin EF
Ohio Basin EF
Ohio Basin EF
TNC EF Hypotheses
TNC EF Hypotheses /Susquehanna EF
TNC EF Hypotheses/Susquehanna
TNC EF Hypotheses
Ohio Basin EF
TNC EF Hypotheses
TNC EF Hypotheses
Ohio Basin EF
Ohio Basin EF
TNC EF Hypotheses
SEASON:
March - May
March - August
May - October
June - September
June - September
June - August
July - September
July - September
December - February
December - February
all seasons
March - May
April - July
May - July
May - October
May - September
June - September
June - September
June - September
July - September
July-September
October - February / March - June
October - June
December - February
December - February
April - June
May - July
December - February
all seasons
February - June
June - August
October - May / April - August
October - November / February - March
February - June
April - August
April - June
October -September
October -September / December - May
November-May
all seasons
all seasons
March-May
all seasons
all seasons
April - August
July - September
GUILD TYPE/SPECIES:
riffle associates
riffle obligates/nest builders/other species
riffle obligates
trout
NS
sensitive species
riffle obligates/brook trout
NS
NS
riffle obligates
riffle obligates
fluvial fish/riffle associates and potadromous fish
migratory residents and riffle associates
nest builders
riffle obligates
walleye
riffle obligates
NS
juveniles and small-bodied fish
riffle obligates
riffle obligates, other fish species
brook trout/salmonids/riffle obligates
brook trout/salmonids/riffle obligates
migratory species
whitefish
nest builders
nest builders
fluvial fish
NS
riffle obligates
NS
brook trout/river chub, horny chub, and walleye/nest builders
salmon, migratory residents, riffle associates
riffle associates
NS
longnose gar
NS
NS
brook trout/nest builders
NS
NS
log perch, walleye, lake sturgeon
NS
NS
NS
trout
FLOW HYPOTHESIS:
Increase in extreme low events impact movement between habitats
Decreased low flows during spawning and rearing reduce recruitment (possible through reduced velocity and depth over redds/accumulation of fines over eggs/exposure of nests)
Decreased low flows reduce high velocity habitats
Decrease in low flow magnitude result in downstream migration of headwater fishes
Decrease in low flows reduce habitat quality, food availability, and individual growth
Decreases in summer low flows lead to replacement of sensitive species
Decrease in low flow magnitudes during juvenile growth reduce recruitment, adult survival, and population size
Low flows result in critical impacts on DO
Winter low flows must not be depleted to the point of ice out and scour
Decrease in low flow magnitude decrease availability and access to riffle habitats
Significantly reduced flow magnitudes will cause local extirpation or reduced growth
Reduced spring flows disrupt timing of spawning due to lack of a correctly timed spawn-triggering pulse
Reduction in seasonal flows reduces the availability of or connectivity to shallow-slow habitats
Stable flows are needed to keep males on nests
Decreased flow magnitude leads to decreased habitat and food availability
Decreased flow magnitude reduces connectivity between pools and riffles
Decrease in median flow limits the quality and availability of riffle habitats
Decrease in seasonal flow magnitude results in loss of persistent habitats and causes a shift in species abundance or assemblage
Decrease in magnitude of flows restricts persistence and access to shallow shoreline habitats
Decreased flows during spawning limits juvenile growth
Low flows reduce high velocity habitat for swimmers
During spawning period flows must be high enough to maintain connectivity and migration to spawning areas and redd sites
During egg incubation, redds and riffle habitat need adequate flow for O, flush sediment (prevent suffocation of eggs), and prevent ice build-up/infiltration into eggs
Decreases in seasonal flows reduce deep pool refugia for adult migratory residents
Late winter drawdown impacts white fish (spawn in late fall)
High flows delay spawning
Stable flows are needed to keep males on nests
High flows induce stress on fish that have moved into slow deep pools during the winter when cold water slows metabolism
Increase in high flow frequency, magnitude, and/or duration destabilizes habitats and flushes preferred substrates for substrate specialists
Increase in magnitude of high flows reduces availability of suitable spawning riffles and margins or impairs egg and larval development
Increase in high flow frequency, magnitude, and/or duration shifts species assemblage
Increase in high flow magnitude scours nests, damages developing eggs, or flushes eggs downstream
Increases in high flow magnitude and duration delay upstream migration
Fish in navigation reaches need high flows to provide connectivity to upstream spawning tributaries
Reduction in high flow events limits connectivity to and quality of oxbow and backwater habitats, reducing fish reproduction and species diversity
Reduction in high flow magnitude restricts access to floodplain, reducing successful reproduction
Moderately high flows facilitate seasonal and annual movement of fish
Moderately high flows help flush sediment, maintain channel habitats, and oxygenate habitats
High flow pulses required to clear gravel and maintain riffle habitat before fall spawning / Loss of flushing flows reduces spawning success
Significantly reduced magnitude, timing, and frequency of flood flows causes loss of seasonal connectivity and off-channel habitats
Changes to intermediate flood disturbances will reduce maintenance of active channel and backwater habitats
Magnitude and pattern of spring flood pulse temperatures provide cues for spawning
Increased flashiness causes loss of fluvial specialists
Increased flashiness restricts access to gravel spawning habitats and reduces success of eggs and larval development
Increased flashiness dewaters nests and reduces year class strength
Small storm events are needed to flush sediment and maintain habitat