Eastern Brook trout: Joint venture

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Eastern Brook trout Joint venture

• Editors
• M. Hudy, USDA Forest Service
• T.M. Thieling, USDA Forest Service, James Madison
  University
• N. Gnat Gillespie, Trout Unlimited
• Eric P. Smith , Virginia Tech

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and a cast of thousands

• New York
• D. Bishop
• J. Robins
• B. Hammers
• F. Angold
• W. Pearsall
• C. Guthrie
• D. Zielinski
• F. Linhart
• D. Cornwell
• W. Elliot
• L. Suprenant
• B. Angyal
• R. Pierce
• M. Flaherty
• F. Flack
• R. Preall
• J. Daley

• Virginia
• Larry Mohn
• Paul Bugas
• Steve Reeser
• Maine
• Merry Gallagher
• Paul Johnson
• Gregory Burr
• Rick Jordan
• Ron Brokaw
• Forrest Bonney
• David Howard
• James Pellern
• Francis Brautigan
• Timothy Obrey
• Nels Kramer
• David Basley
• North Carolina
• Doug Bestler

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The Big Picture Through the eyes of a brook
trout!
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• Study Area
• 25 of native range
• 70 of native range in the U.S.

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Assessment goals

• Assess the loss of reproducing brook trout
  habitat as it relates to historic
  (pre-settlement) levels.
• Assess watershed perturbations by expert opinion
  
• Assess watershed level metrics using GIS
• Make an interactive database on the web (ArcIMS)

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What the assessment is not

• Classification of wild trout
• Classification of recreational fishing quality or
  potential
• A value judgment on past or current management
  practices
• A viability assessment

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Methods
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What scale?
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Appropriate Scale

• 5th level too big
• Stream reach too small (too many)
• 6th level just right

• How big is a 6th level watershed?
• 41-163 sq. km
• 1 quadrangle map

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6th Level watersheds classifications (n gt 10,000)

• Preliminary classification with GIS layers
• Validation of Classifications with experts

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Brook trout population status classifications by
6th level watershed

• Present Reduced
• (50 to 90 of historic habitat occupied)
• Present Greatly reduced ( lt 50 of historic
  habitat occupied)

• Unknown (no data)
• AbsentUnknown history (no brook trout today, not
  known if extirpated or never occurred)
• Never occurred
• Extirpated
• Present Qualitative
• (no quantitative data in watershed or gt 10
  years old)
• Present Intact
• (gt 90 of historic habitat)

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Reducing subjectivity

• Consistency rules
• Data standards (quality age)
• Broad classification categories
• No brainers
• high repeatability
• Standard validation procedures with experts for
  each subwatershed (N gt 11,000)

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Consistency Rules for reduction

• Documented loss of reproducing populations by
  current or historical data
• Only exotic coldwater species reproducing (within
  MacCrimmon and Campbell range)
• Exotics greater than 75 of coldwater fish
  biomass or numbers
• Brook trout carrying capacity reduced by greater
  than 90 from historic or reference data within
  the watershed
• Reproducing brook trout stream inundated by dam
  and converted to warm water
• Acid mine drainage, acid rain, etc eliminated
  habitat
• Severe channelization (stream paved)
• Watershed changed from coldwater to warmwater by
  riparian changes (documented water temp)

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Results
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Study Area 6th level watersheds

• Unknown no data 14
• Absent unknown history 5
• Extirpated 21
• PresentQualitative
• 19
• Present Intact 5
• Present Reduced 9
• Present Greatly reduced 27

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Final Classifications

• Extirpated
• Predicted Extirpated from Unknown and Present
  qualitative
• Reduced gt 50
• Predicted Reduced gt 50 from Unknown and Present
  qualitative
• Intact gt 50
• Predicted Intact gt 50 from Unknown and Present
  qualitative

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Study Area 6th level watersheds

• Extirpated 21
• Predicated extirpated 8
• Reduced gt50
• 28
• Predicated Reduced gt50 7
• Intact gt50 14
• Predicated Intact gt50 17
• Absent Unknown History 5

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Limiting factors by watershed(expert opinion)
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Limiting factors by watershed(mark all that
apply)

• 1 high impact loss of life cycle component
• 2 medium impact life cycle component reduced
  but not lost
• 3 low impact potential future impact on life
  cycle component reduction or loss

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Streams
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Top Ten Threats Streams Cumulative Categories 1
2n 4,484

• Agriculture 36
• High Water Temperature 35
• Sediment-Roads 27
• All Exotics 26
• Urbanization 25
• Riparian Habitat 22.
• Brown trout 19
• Stream Fragmentation - Roads Culverts 17
• Dams 15
• Forestry 15

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• Number 1 perturbation
• Agriculture

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• Number 2 perturbation
• water temperature

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• Number 3 perturbation
• urbanization

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• Number 4 perturbation
• Exotics

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• Number 12 perturbation
• Acid mine drainage

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Lakes
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Top Ten Threats Lakes Cumulative Categories 1
2n 1,294

• All Exotics 25
• Smallmouth bass 14
• Other cool/warm exotics 13
• Largemouth bass 10
• Dissolved oxygen 4
• Eutrophication 4
• Forestry 3
• Water temp 3
• Brown trout 3
• Northern pike 3

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GIS Analysis
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10,838 6th level subwatersheds
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Candidate Metrics
Subwatershed and Subwatershed Corridor Scale

• Road Density
• Dams/area
• Road/Stream Crossings
• Population Density
• NO3 and SO4 Deposition
• Exotics
• Elevation
• Latitude/Longitude
• Land Use (21 land use classes)

Over 60 Metrics
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National Land Cover Data (30m)
Human Uses
Natural Cover

• Low Intensity Residential
• High Intensity Residential
• Commercial/Industrial/ Transportation
• Quarries/Strip Mines/Gravel Pits
• Transitional
• Orchards/Vineyards
• Pasture/Hay
• Row Crops
• Small Grains
• Fallow
• Urban/Recreational Grasses

• Woody Wetlands
• Emergent Herbaceous Wetlands
• Open Water
• Perennial Ice/Snow
• Bare Rock/Sand/Clay
• Deciduous Forest
• Evergreen Forest
• Mixed Forest
• Shrubland
• Grasslands/Herbaceous

Derived Cover

• Total Forested
• Agriculture
• Residential
• Human Use

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Metric testing screening

• Completeness
• Correct for watershed size
• Range
• Redundancy
• Responsiveness to classification categories

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Model Development

• We tried
• Single metric logistic regression
• Multi metric logistic regression
• CART Classification Trees
• Discriminate
• Nearest neighbor

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We picked CART classification trees
Because

• Higher of correct predictions
• Easier interpretation than logistic (especially
  trinomial) multi metric
• Helps in development of thresholds for land
  managers

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What CART classification trees do

• Look at all possible combination of metrics and
  metric values to most efficiently divide the
  dataset
• Sets up a decision tree using different metric
  values as splitting criteria (20 80 couplets)
• Predicts the probability of correct
  classifications at terminal nodes

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Final Core Metrics for CART Analysis

• Forested land
• Agricultural land
• Combined N03 SO4 deposition (kg/ha)
• Road density (km/km2)
• Mixed forested land in corridor
• Latitude (decimal degrees)

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Model Development CART

• M1 Presence Extirpated
• 5 core metrics
• M2 Presence Extirpated
• 5 core metrics latitude
• M3 Extirpated Reduced gt 50 Intact gt50
• 5 core metrics
• M4 Extirpated Reduced gt 50 Intact gt50
• 5 core metrics latitude

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M1 Presence Extirpated79 correct overall80
Extirpated78 Present

• Forest lt 68
• Deposition lt 23 kg/ha
• Road Density lt 1.19 km/km2
• Riparian Mixed Forest lt12
• Deposition lt 23 kg/ha
• Deposition lt 28 kg/ha

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M3 Extirpated Reduced gt 50 Intact gt 5071
correct overall76 Extirpated64 Reduced79
Intact

• Forest lt68
• Deposition lt 28 kg/ha
• Deposition lt 19 kg/ha
• Agriculture lt 27
• Road Density lt 1.67 km/km2
• Deposition lt 18 kg/ha

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Study Area 6th level watersheds

• Extirpated 21
• Predicated extirpated 8
• Reduced gt50
• 28
• Predicated Reduced gt50 7
• Intact gt50 14
• Predicated Intact gt50 17
• Absent Unknown History 5

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Model Analysis
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Areas of misclassification
1. Extirpated subwatersheds misclassified as
presentExotic species?
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Areas of misclassification
2. Reduced and Intact subwatersheds predicted as
Extirpated Low Total Forest and High
Deposition. Watershed size??
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Key findings
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Trouts there be good store in every brook,
ordinarily two and twenty inches

• John Josselyn New England 1674

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Brook trout are extirpated from 29 of the
subwatersheds and reduced gt 50 in another 35

• The majority of large riverine habitats are gone

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Presence does not equal persistence
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Even with no further degradation many of the
Reduced gt 50 populations could become Extirpated.

• No connectivity or redundancy to reestablish
  populations after stochastic events
• Exotics fill in
• 330 subwatersheds highly vulnerable to extirpation

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I have given the matter considerable thought,
and frankly I can think of not one stream that I
would classify as predominately brook trout. This
state and neighboring states have spent most of
their time and money stocking brown trout in what
were good brook trout waters

• All about Brook Trout from Maine to California
  Bob Elliot 1950

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Exotics, Exotics, Exotics!!!

• Biggest non land use threat
• Rainbow trout in south east
• Brown trout in New York, New England
• Smallmouth bass in lakes
• Metric ??

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If you dont know where you are going any road
will get you there !
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Important quantitative data gaps exist for many
stream habitats (33 ) in large portions of
Maine, New Hampshire, New York with smaller gaps
in portions of Vermont, Massachusetts and West
Virginia.

• Need to validate the predictive models
• Quantitative needed for monitoring land use
  changes and exotics

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very large and nice trout were formerly caught
here but since the introduction of pickerel about
the year 1820 but very few trout have been
taken
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Lake populations have all but been eliminated
except for a few strong holds in Maine

• Vulnerable to exotics
• Vulnerable to land ownership changes

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While many extirpations and losses occurred at
the turn of the century, many documented losses
have occurred in the last ten years.

• 75,000 dams
• 2 million miles road
• 90 million people

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Land use metrics at the subwatershed level are
useful predictors of brook trout for land managers
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Core Metric Total Forest

• Land managers should be concerned as Total
  Forested in the subwatershed drops below 68
• Only 6 of Intact gt 50 subwatersheds have less
  than 68 Total Forest.
• 85 of Extirpated subwatersheds have less than
  68 Total Forest

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Core Metric Agriculture

• Land managers should be concerned if the
  Agriculture in the subwatershed is in the 12-19
  range or greater
• Only 17 of Intact gt 50 subwatersheds have
  greater than 19 Agriculture
• 74 of Extirpated subwatersheds have greater than
  12 Agriculture

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Core Metric NO3 SO4 Deposition (kg/ha)

• Land managers should be concerned if the
  Deposition in the subwatershed is in the 24 - 33
  kg/ha range or greater
• Only 23 of Intact gt 50 subwatersheds have a
  Deposition greater than 33 kg/ha
• 94 of Extirpated subwatersheds have a Deposition
  greater than 24 kg/ha

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Core Metric Riparian Mixed Forest

• Land managers should be concerned if the
  Riparian Mixed Forest in the subwatershed
  corridor is less than the 17-20 range
• Only 35 of Intact gt 50 subwatersheds have a
  Riparian Mixed Forest less than 17
• 81 of Extirpated subwatersheds have a Riparian
  Mixed Forest less than 20

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Core Metric Road Density (km/km2)

• Land managers should be concerned if the Road
  Density in the subwatershed is in the 1.8-2.0
  km/km2 range or greater
• Only 17 of Intact gt 50 subwatersheds have a
  Road Density greater than 1.8 km/km2
• 72 of Extirpated subwatersheds have a Road
  Density greater than 2.0 km/km2

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Next steps Brook trout populations 2015 ?
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Brook trout Life Histories
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