Evaluating genetic structure of interior Redband trout in Idaho Christine Kozfkay, Matthew Campbell, Kevin Meyer, Dan Schill, Bruce Zoellick.
Interior O. Mykiss in Idaho Found east of the Cascades upstream to Shoshone Falls on Snake R. and Kootenai Falls on Kootenai R. Not in Clark Fork or Coeur d'alene drainages Resident pops above Hells Canyon Dam are found in Boise, Weiser, Payette, Owyhee, Wood, Snake, Bruneau R. drainages
Interior Columbia R. O. Mykiss Includes formerly anadromous steelhead Boise
Interior Columbia R. O. Mykiss Found in montane streams as well as arid desert drainages Juan Calvillo.
Desert vs. Montane Populations Montane Streams: Higher elevations, cooler summer water temperatures, larger substrate, more canopy covering, higher gradient streams Desert Streams: Elevations 750 to 2560 m, summer water temperatures 18 26 degrees
Desert vs. Montane Populations Desert Streams: Elevations 750 to 2560 m, summer water temperatures 18 26 degrees
Anadromous Columbia R. O. mykiss (Steelhead) Genetic Structure has been intensively studied Anadromous O. mykiss are structured at the watershed level
Goal: Investigate genetic structure of resident O. mykiss in Idaho Role of environment, hatchery stocking, anadromous life-history
Hypothesis 1: H o : Genetic structure (F ST ) is the same for populations in montane and desert drainages Follows stream hierarchy and/or geographic distance (like steelhead)
Montane: Desert: H a : Genetic structure (F ST ) is greater for populations within the desert drainages due to habitat
Hypothesis 2: H o : Genetic diversity levels are the same for populations in montane and desert drainages
Montane: Desert: H a : Genetic diversity is greater for populations within the montane drainages because gene flow is higher
Montane: Desert: H a :Genetic diversity levels are similar among montane and desert populations but diversity is different (selection).
Sampling 2,271 samples collected from 8 Weiser watersheds in Idaho Payette 4 desert, 4 montane Snake Boise Big Wood 13 microsatellite loci Bruneau Owyhee Salmon Falls
Methods Genetic diversity = avg. number of alleles per locus, avg. heterozygosity Compared across groups (montane vs. desert, 8 watersheds) and to steelhead
Methods Cont d Genetic Structure: Dendrogram - NJ tree using CSE gen. distance F ST analyses AMOVA analyses - Tests how genetic variation is partitioned between and within groups (Montane vs. Desert, 8 Watersheds, Hybridized vs. Nonhybridized)
0.1 Bruneau R Juniper Cr Squaw Cr Shack Cr. Cottonwood Cr. NF Salmon Falls Cr. MF Shoshone Cr. Crab Cr. McMullen Cr. *Deer Cr. Willow Cr. Owyhee Cr. NF Owyhee Cr. Keithly Cr. Indian Cr. Cold Springs Cr. Little Canyon Cr. Bennett Cr. Dive Cr. Jordan Cr. Tripod Cr. Willow Cr. EF Big Wood Cr. Red Warrior Cr. Big Wood R. NF Thompson Cr. Little Wood R. Copper Cr. Smith Cr. SF Boise R. Salmon Falls Cr. Boise R. McConaughey Arlee Hayspur Erwin Hilderbrand D Kamloops Hilderbrand Eagle Lake Shasta Fish Lake MW Jarbidge R. Petes Cr. 2nd Fork Squaw Cr. Beaver Cr. Shoofly Cr. Little Jacks Cr. Wickahoney Cr. Duncan Cr. Big Jacks Cr. Fawn Cr. Silver Cr. Jump Cr. (above) Jump Cr. (below) Little Weiser Cr. Hornet Cr. Big Smokey Cr. Whiskey Jack Cr. Johnson Cr. Pikes Fork Cr. MF Boise R. Roaring R. Longs Cr. Clear Cr. Eightmile Cr. Williams Cr. Manns Cr. EF Weiser R. Cedar Cr. Sinker Cr Results Hybridized Pops + Hatchery References
Genetic Diversity Results Avg. H e ranged from 0.48 to 0.78, Avg. # alleles per locus ranged from 3.23 to 10.77 Diversity was significant different in each watershed:» Weiser River - highest» Snake River - lowest
Genetic Diversity Results Mountain Pops (no hybrids): H e = 0.68, Avg. # Alleles = 4.8 Desert Pops (no hybrids): H e = 0.66, Avg. # Alleles = 4.4 Hybridized Pops: H e = 0.70, Avg. # Alleles = 5.05 Non-hybridized Pops: H e = 0.67, Avg. # Alleles = 4.6
Genetic Diversity Results Steelhead Pops: H e = 0.75, Avg # Alleles = 9.4 Montane Pops (no hybrids): H e = 0.68, Avg. # Alleles = 4.4 Desert Pops (no hybrids): H e = 0.66, Avg. # Alleles = 4.8 Diversity is higher in Steelhead populations than resident redband trout populations!
How is diversity partitioned? Largest amount of diversity partitioned between pops (89%), between drainages (10%), between montane and desert groupings (1%) Diversity between hybridized and non-hybridized groups is 5% while montane/desert groupings is only 1%
How is diversity partitioned? Locus Ots4: All Loci: N = 186 N = 166 N= 184 N = 189 N = 202
F ST Results Very Large Pair-wise Fst Values Large Moderate Small Geographic Distance Avg. F ST Montane = 0.07; Avg. F ST Desert = 0.13
Major Findings Genetic diversity is structured at the population and watershed levels
Mountain: Major Findings Desert: Genetic structure (F ST ) is greater for populations within the desert drainages due to habitat barriers but avg. diversity is not sig. lower
Mountain: Major Findings Desert: Genetic diversity levels are similar among mountain and desert populations and different subsets of the anadromous gene pool are represented in each population
Major Conclusions Resident life-history, hybridization, and environmental barriers all influence genetic structure Montane and desert populations - lower amounts of diversity than steelhead populations but not different types of diversity. Management of populations should be at the population and watershed scales
Questions?