Quantifying Genetic Diversity Steelhead Stocks
Eric Parkinson, Art Tautz, Bob Hooton
BC Min. Water, Land & Air Protection
Photo: E. Keeley
~70 spp.
B.C.950,000 km2
Tennessee110,000 km2
Geographic area and the number of native species
of Freshwater Fish
~250spp.
Why care about genetic diversity:BC has very few species but lots of
Intraspecific diversity
Post-Glacial Dispersal RoutesBering Refuge
Queen Charlotte Refuge
Columbia RefugeCoastal Refuge
Missouri Refuge
Edge of Ice Sheet
Why so few species?
Fish Species at Risk in B.C.Three Directions
1. Systematic assessment of all species
2. Focal studies on specific species that are judged to be most at risk
3. Identify populations representing rare or endangered ecotypes within each species
1:50,000 Lakes and Streams (i.e. Lakes >1 ha)
Digital BC Watershed Atlas
Linked to info on: Stream length, size, gradient, flow, lake influence, species records, land use, stocking
records, terrain maps, geology etc. for 20,000 3rd order & greater watersheds
Steelhead Stock Structure
The smallest independent unit– stock = VSP?– Genetically isolated– Large enough to be viable
Genetic Groups of Stocks share:– Major Phylogenetic Associations = ESU? – Adaptation to a common environment = Strata?
Management Groups have similar: – Exploitation rates, hatchery influence, management goals – Can cut across genetic groups
Steelhead Stock Structure
The smallest independent unit– stock = VSP?– Genetically isolated– Large enough to be viable
Genetic Groups of Stocks share:– Major Phylogenetic Associations = ESU? – Adaptation to a common environment = Strata?
Management Groups have similar: – Exploitation rates, hatchery influence, management goals – Can cut across genetic groups
Steelhead Stock Structure
The smallest independent unit– stock = VSP?– Genetically isolated– Large enough to be viable
Genetic Groups of Stocks share:– Major Phylogenetic Associations = ESU? – Adaptation to a common environment = Strata?
Management Groups have similar: – Exploitation rates, hatchery influence, management goals – Can cut across genetic groups
Chehalis R.Weaver Cr.
Examples of adaptive and molecular differences among Steelhead in adjacent streamsRule: Every watershed that empties into either
the ocean or a large river contains a stock
650
700
750
800
Oyster River Quinsam River
Len
gth
at M
atu
rity
(mm
)
LDH and MDH Allozyme Frequencies
Stock Structure is quantified using data on genetic and phenotypic differences
Exclude Very Small Watersheds“Viable Salmonid Population”
Use various measures of size– Stream order and magnitude– Watershed area– Length of anadromous stream
Goal is a Viable Population– Run size > 20– 5 yr generation gives > 100
– Ne > 30?
Defining Steelhead Population Structure• Size, location, and drainage links come from
the Watershed Atlas• Find all independent stocks• Eliminate very small streams• Review by Regional Biologists
~ 630 viable steelhead stocks
in~ 580 BC streams
Steelhead Stock Structure
The smallest independent unit– stock = VSP?– Genetically isolated– Large enough to be viable
Genetic Groups of Stocks share:– Major Phylogenetic Associations = ESU? – Adaptation to a common environment = Strata?
Management Groups have similar: – Exploitation rates, hatchery influence, management goals – Can cut across genetic groups
Major Phylogenetic Lineages
Species
Breeding isolation
Recent, incomplete Ancient, complete
Sel
ecti
ve F
orc
es
Weak
StrongDisruptive
StrongConvergent
Populations
Diverge into different ecotypes
Maintains similar ecotypes
Cryptic species
Steelhead Phylogenetic Groups:
Defined using patterns of molecular genetic
variation
Queen Charlotte Glacial Refuge
South Coast Refuge
South Interior Refuge
Major Phylogenetic Lineages
Species
Breeding isolation
Recent, incomplete Ancient, complete
Sel
ecti
ve F
orc
es
Weak
StrongDisruptive
StrongConvergent
Populations
Diverge into different ecotypes
Maintainssimilar ecotypes
Cryptic species
Database of Steelhead Stocks
Watershed Code
DFO Escapement
Database
Hatchery Records
FISS Records
Land Form Databases
Land Use Databases
The Watershed Code links the Stock Database to a variety of useful info
Low Lake Influence Land (%Area)Freshwater (%Area)
Large Watersheds Stream Magnitude (max)Watershed AreaStream Order (max)
Cold, High Relief, Temperature (min)High Elevation Elevation (std.dev)
Ice (%area)Elevation (max)Elevation (mean)Elev >800m (%Area) Alpine (%area)Temperature (mean)Elev <300m (%Area)
Watershed Type Variable
High elevation Minimum ElevationInterior Migration DistanceDry Water Yield
Moderate Gradient 16-30%Gradient Gradient 9-15%
>70% gradient51-60% gradient
Low Gradient, Gradient 31-50Low Relief Gradient 3-8%
Elev 300-800mWetlands (%Area)
Cold, Temperature (max)High Latitude Latitude
Land Form Data can Characterize Watersheds Using Principle Components Analysis
e.g. of a Principle Component
Interior, Dry Coastal, Wet
Habitat differences can be used as a
proxy for adaptive differentiation
rare
common
Which stocks have the most unusual habitat?-Interior Watersheds-Low relief coastal-Lake Influence coastal
6
15
10
12
16
17
8
13
3
2
5
1
9
11
14
7
4
15
16 17
13
14
1012
9
11
6
8
7
54
21
3
Genetic Distance from Molecular Markers
2 ESUs
17 Stocks
4 Ecotypes(strata?)
Geographic Layout
Large Lake Piscivores
Coastal Summer-Run Steelhead
Interior Fall-Run Steelhead
Phylogenetic Groups
Interior
South Coast
North Coast
Ecotypes cut across Phlylogenetic Groups
Ecotypes
Phylogenetic vs. Adaptive Structure
Contrast with US Pacific NW
Only 3 ESUs– In a Province the size of
Wash, Ore, Calif, Idaho combined
Lots of very small coastal stocks– Rocky, heavily-indented
coastline
Reason: BC was almost entirely glaciated
Steelhead Stock Structure
The smallest independent unit– stock = VSP?– Genetically isolated– Large enough to be viable
Genetic Groups of Stocks share:– Major Phylogenetic Associations = ESU? – Adaptation to a common environment = Strata?
Management Groups have similar: – Exploitation rates, hatchery influence, management goals – Can cut across genetic groups
Hatchery History of Steelhead Stocks
Currently StockedStocked Prior to 1993Never Stocked
HatcheryHistory
Which stocks and ecotypes have not had any hatchery influence?
June-JulySept-OctDec-April
Peak Time of River Entry
Currently StockedPrior to 1993
HatcheryHistory
Land use data can be used to identify habitat concerns
0.00
0.20
0.40
0.60
0.80
1.00
< 5% 5-10% 10-20% >20%
Percent of Area Logged
Pro
po
rtio
n o
f W
ater
shed
s
BC
VanIs
BC
VanIs
} < 300m Elevation
} >50% Gradient
Management Units can also be groups of stocks that share common management goals, issues and policies
Steelhead Stock Structure
Define the Distribution Define Stock Structure (VSP?)
– Use associations between geographical isolation and molecular genetic variation
Define Genetic Groups– Major Phylogenetic groups share a
common ancestry (ESU?)– Ecotypes share common environments
(Strata?) Define Management groups
NeutralConvergent Disruptive
Selection gradient
Ge
net
ic is
ola
tion
Re
cen
t, in
com
ple
teA
nci
ent
, co
mpl
ete
Adaptive differentiation
Diff
ere
ntia
tion
at n
eut
ral l
oci
Size of Unit
NAME COQUITLAM PITT STOCK_NO_(WShedCode) 100024500 100026700ORDER 4 6MAGNITUDE 81 525CONNECTS_T 100 100CONNECTS_AT (km) 34 37Number of 3rd Order streams 4 14Watershed Area (km2) 270 1355MGMTAGG Nfraser NfraserSTATUS ExtremeCC ExtremeCCX Albers 1233606 1243044Y Albers 488653 507775Run Timing Winter WinterHatchery Classification Wild WildLast Date Stocked Jun-96Max Size (g) 192Max Number 500000Max Size since 1993 (g) 192Max No since 1993 9211Monitored? No NoAnadromous Length (km) 17.78 84.4Distance from Ocean (km) 34 37ObStructions Yes YesHarvest Analysis Observation Yes YesSteelhead Observation Yes YesSalmon Spp Observation Yes YesCoho Observation Yes YesRainbow Observation Yes Yes
Other useful info
Fish Presence/AbsenceInformation is used t
11111
Steelhead Sportfish RecordSteelhead Inventory Record
Salmon Inventory RecordCoho Inventory Record
Rainbow Trout Record
110
1110110
110
111
1110
11111
11110
11111
11111
110
101
11111
111
110
110110
10111
111
110
10111
110
11111
11111
11111
1111111111
1111111111
100
01100
0
0
1111110
10110
11111
11111
11111
110
1100
110110
1110 0
10110
11111
P<0.01
P<0.01
SamplesWithin
Streams
AdjacentStreams
<20 km <200 km Regions
Geographic Range
Inde
x of
Var
ianc
e in
Allo
zym
e Fr
eque
ncy
LDH
SOD
Allozyme Frequencies in Steelhead
vary among adjacent streams
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