Marine migrations of Steelhead, Coastal Cutthroat, and Steelhead x Cutthroat hybrid smolts
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Megan Moore, NOAA Fred Goetz, University of Washington Barry Berejikian, NOAA Skip Tezak, NOAA Don Van Doornik, NOAA Jose Reyes Tomassini, NOAA
description
Marine migrations of Steelhead, Coastal Cutthroat, and Steelhead x Cutthroat hybrid smolts. Megan Moore, NOAA Fred Goetz, University of Washington Barry Berejikian , NOAA Skip Tezak , NOAA Don Van Doornik , NOAA Jose Reyes Tomassini , NOAA. Extent of Hybridizaton. - PowerPoint PPT Presentation
Transcript of Marine migrations of Steelhead, Coastal Cutthroat, and Steelhead x Cutthroat hybrid smolts
Megan Moore, NOAAFred Goetz, University of Washington
Barry Berejikian, NOAASkip Tezak, NOAA
Don Van Doornik, NOAAJose Reyes Tomassini, NOAA
• Hybridization has been documented in several streams from Alaska to California (first formally documented by Utter 1981*)
• Hybrid swarms are generally not formed in anadromous populations
• Rate of hybridization is generally < %30
• Frequency of occurrence:- Campton and Utter (1985) – 2/23 Puget Sound streams- Bettles et al. (2005) - 13/37 Vancouver Island streams- D. Van Doornik , (2006- 2009) – 8/8 Hood Canal streams (some very low levels)
*CJFAS 38:1626-1635
Anadromous or freshwater-residentsIteroparous
1-4 year freshwater residency
Cutthroat Steelhead
Juvenile habitat Slower water Faster water
Marine habitat Nearshore/estuaries Open ocean
Marine Duration Summer months 1-3 years
Spawning habitat Small tributaries Main river channel
115 phenotypic steelhead 68 phenotypic cutthroat
Study conducted over three years (2006, 2007, 2008) in Big Beef Creek
Steelhead and cutthroat smolts tagged with acoustic transmitters
Four diagnostic microsatellite loci were genotyped to determine hybridization- both SH and CT alleles at all four loci = F1- mix of hetero- and homozygous genotypes = F1+
more SH alleles = SH F1+more CT alleles = CT F1+
“Track” Parameters
Estuarine residence time = last estuary detection – first estuary detection
Total track distance = sum of all track segments
Tortuosity = total track distance/range of track
Hood Canal residence time = last Hood Canal detection – last estuary detection
AquaTrack, developed @ Manchester by Jose Reyes - Tomassini
Consistent frequency of hybridization between phenotypes
Also consistent with results from sampling in 1996 (Young et al. 2001) 22.2%
Phenotypic steelhead hybrids tended to be F1’s while more phenotypic cutthroat hybrids were F1+
Generally, the observed F1:F1+ ratio (1:1.3) deviates from expected (1:6)
Phenotypic Steelhead
Phenotypic Cutthroat
Total Tagged 115 68
Total Hybrids 28* (24.3%) 14 (20.5%)
F1 25 4
F1+ 2 10
CT F1+ 1 10
SH F1+ 1 0
*One hybrid of undetermined type
CT HB SH
Est
uary
Tim
e (d
ays)
0
20
40
60
80
100
120
140
CT HB SH
Tota
l Tra
ck D
ista
nce
(km
)
0
200
400
600
800
CT HB SH
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120
CT HB SH
Tortu
osity
Inde
x
0
5
10
15
20
25
30
MANOVA: Species ~ estuary time + residence time + tortuosity (F2,148 = 0.414, P = 0.000)
Cutthroat Detection Density
Cut
thro
at
Ste
elhe
ad
Hyb
rids
Cutthroat
Hybrids
Steelhead
2008 data
Distance from Big Beef Creek to last location
-50 0 50 100 150
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120 Cutthroat
(km)
Distance from Big Beef Creek to last location
-50 0 50 100 150
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120
Distance from Big Beef Creek to last location
-50 0 50 100 150
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120 Steelhead
Cutthroat
(km)
Distance from Big Beef Creek to last location
-50 0 50 100 150
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120
Distance from Big Beef Creek to last location
-50 0 50 100 150
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120 Steelhead
Cutthroat
Distance from Big Beef Creek to last location
-50 0 50 100 150
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120
Phenotypic Cutthroat Hybrids
(km)
Distance from Big Beef Creek to last location
-50 0 50 100 150
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120
Distance from Big Beef Creek to last location
-50 0 50 100 150
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120 Steelhead
Cutthroat
Distance from Big Beef Creek to last location
-50 0 50 100 150
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120
Phenotypic Cutthroat Hybrids
Distance from Big Beef Creek to last location
-50 0 50 100 150
Res
iden
ce T
ime
(day
s)
0
20
40
60
80
100
120
Phenotypic steelhead hybrids
(km)
Rates of hybridization are consistent (as opposed to episodic) and low in Big Beef Creek
Phenotypic steelhead hybrids tend to be F1’s, while phenotypic cutthroat hybrids are more likely F1+
Overall, there are fewer backcrosses than expected, suggesting lower hybrid fitness
Hybrids display different migration behaviors than do pure steelhead or cutthroat
Most hybrid migration parameters are intermediate to pure species
Hybrids do not necessarily “act” like the species they resemble
Conservation Concern: Species collapseExtinction of native genotypes
Anthropogenic Causes: Habitat loss/destruction
Evolution: Increased genetic diversity Novel genetic combinations
Increased evolutionary potential:Ability to respond to environmental change and/or variable environment
Adaptive Response: Low population sizes
Increase reproductive success:Fewer mates = less competitionFemales less choosy, sneaking more successfulBetter to mate interspecifically than not at all
