Cold Water as a Climate Shield to Preserve Native Trout through the 21 st Century

Transcription

1 Cold Water as a Climate Shield to Preserve Native Trout through the 21 st Century Michael Young, Dan Isaak, Dave Nagel, Dona Horan, Matt Groce Northern Rockies Adaptation Partnership

2 Climate Changing Western Streams ( ) b) Less snow & earlier runoff Warmer Air Temps c) C Decreasing summer flows Mote et al Stewart et al Increasing wildfire Leppi et al Westerling et al. 2006

3 Temperature Trends In Northwest Rivers Fraser River - Annual = 0.18 C/decade Columbia River - Summer = 0.40 C/decade Morrison et al Crozier et al Snake River, ID - Summer Missouri River, MT - Summer = 0.27 C/decade = 0.33 C/decade Isaak et al Climatic Change 113:

4 Why cold-water fishes? Most species at risk are in freshwaters Ectotherms Temperature is destiny Losses from climate change are underway Williams et al Bull trout, EF Bitterroot River Wenger et al Eby et al. 2014

5 A future for coldwater fish? Most projections are for % declines Eaton & Schaller 1996 Reusch et al Rahel et al Mohseni et al Flebbe et al Rieman et al Kennedy et al Williams et al Wenger et al Almodovar et al etc. Substantial uncertainty Depends on emissions Depends on GCMs Depends on habitat models Depends on species 1980s baseline ( ) Hamlet al s ( ) 2080s ( ) 2040s = moderate change 2080s = extreme change

6 Precise information needed to empower local decision makers Previous High-resolution models landscape are too coarse models Not Good Enough for Zombie Detection I m going to invest here instead of here Rieman et al. 2007

7 Assessing the vulnerability of native trout to climate change NRAP project Occupancy models Accurate, necessary, sufficient Consider invasive species Founded on field data Predictions and projections Address climate change Straightforward to understand and apply Versatile and specific in space & time Identify climate refugia

8 Taking Climate into the Water Where Fish Live Climate model (air temp & precip) Regional patterns Stream temperatures & flow Stream reach patterns VIC

9 GIS data for stream temperature & flow VIC streamflow scenarios Mean August stream temperature scenarios Google Stream flow metrics Liang et al J. Geophys Res 99: Wenger et al Water Res Res 46:W Hamlet et al Atmosphere-Ocean 51: Isaak et al Ecol. Apps. 20: Isaak et al Climatic Change 113: Luce et al Wat Res Res DOI: /2013WR Ver Hoef et al Environ Ecol Stat 13: Ver Hoef & Peterson Journal Am Stat Ass 105:6 18. Google NorWeST stream temp

10 High-resolution stream temperature scenarios 40,397 summers of data - 380,000 stream kilometers modeled R 2 = 0.91; RMSE = 1.0 C; 1-km resolution

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12 1-km data model Process Additional filters Gradient 15% & width 1 m ArcGIS Python script aggregated discrete areas < 11 C into cold-water habitats Assumed Trout populations >1 km Life history immaterial

13 Cold-water habitats (1980s) 70,335/259,052 stream km in the analysis area 56,545 km 52,966 km

14 Cold-water habitats (2040s) 43,556/248,330 stream kilometers in analysis area 37,841 km 31,714 km

15 Cold-water habitats (2080s) 29,789/246,759 stream kilometers in analysis area 24,296 km 20,752 km

16 Native trout occurrence within cold-water habitats Present Absent n = 566 n = 512 Fish data from literature & agency reports Predictors (for juveniles) Habitat size (km 11 C) Stream slope Temperature Mean Minimum % Brook trout

17 Model performance: overall & in climate refugia Classification success If this increases... Coldwater habitat Stream slope Temperature % Brook trout 0.5 (78%), 0.9 (96%) P(occupancy)... : 17 km, 65 km Minimum: (@50%, CWH 2x) 0.5 (85%), 0.9 (98%) P(occupancy)... : 1 km, 13 km, Mean: (fails below 8 C, bullies above 11 C) (at 50%, CWH 2x)

18 Occurrence Probability Map 1980s n = 3,750 habitats 225 >0.9 habitats

19 Occurrence Probability Map 2080s n = 1,973 habitats 33 >0.9 habitats

20 Occurrence Probability Map 2080s 50% Brook Trout

21 Occurrence Probability Map 1980s n = 6,784 habitats 2,184 >0.9 habitats

22 Occurrence Probability Map 2080s n = 4,502 habitats 917 >0.9 habitats

23 Occurrence Probability Map 2080s 50% Brook Trout

24 Land administration GAP analysis <11 C streams in bull trout range Land status 1980s 2080s Private 5,580 (10.5) 1,099 (5.3) Tribal 1,779 (3.4) 713 (3.4) State/City 1,621 (3.1) 420 (2.0) BLM 1,534 (2.9) 512 (2.5) NPS 652 (1.2) 182 (0.9) TNC 157 (0.3) 30 (0.1) FS-wilderness 6,483 (12.2) 2,854 (13.8) FS-nonwilderness 34,068 (64.3) 14,575 (70.2) Other 1,093 (2.0) 367 (1.8) Totals: 52,966 20,752 ~90% on public lands 13 15% protected Gergely and McKerrow PAD-US National inventory of protected areas: U.S. Geological Survey.

25 Implications & adaptation for the future Prospects Actions (in situ) Actions (ex situ) Translocation Supplementation Duplication Refounding Broodstocks Severe habitat losses & range contraction Extinction debts & risky investments Still some resilient habitats Protect habitats Community conservation Substantial habitat losses & range shrinkage Still widely distributed Many suitable habitats, but many at risk from nonnative species Protect habitats Isolate habitats? Remove nonnatives

26 Field data: challenge and opportunity 1980s n = 3,750 habitats 225 >0.9 habitats Present now & later?

27 Monitoring the biodiversity portfolio: edna Pioneering this approach for identification and detection Optimizing for local to rangewide assessments Developing user-driven applications Costs: pennies on the dollar

28 Acknowledgements: John Chatel & Scott Vuono - Sawtooth National Forest; Ralph Mitchell, Herb Roerick, & Mike Kellett - Boise National Forest; Bart Gamett - Salmon-Challis National Forest; James Brammer & Steven Kujala - Beaverhead-Deerlodge National Forest; Joan Louie - Lolo National Forest; Leslie Nyce - Montana Fish, Wildlife and Parks; Seth Wenger University of Georgia; Kevin Meyer Idaho Fish & Game; Phil Howell

29 Published Fish Literature Sources Al-Chokhachy & Budy Demographic Characteristics, Population Structure, and Vital Rates of a Fluvial Population of Bull Trout in Oregon. TAFS 137: Allen et al Distribution and Movement of Bull Trout in the Upper Jarbidge River Watershed, Nevada. U.S. Geological Survey, Open-File Report Benjamin et al Invasion by nonnative brook trout in Panther Creek, Idaho: Roles of local habitat quality, biotic resistance, and connectivity to source habitats. TAFS 136: Dunham & Rieman Metapopulation structure of bull trout: Influences of physical, biotic, and geometrical landscape characteristics. Ecol. Appl. 9: Dunham et al Influences of Wildfire and Channel Reorganization on Spatial and Temporal Variation in Stream Temperature and the Distribution of Fish and Amphibians. Ecosystems 10: Eby et al Evidence of Climate-Induced Range Contractions in Bull Trout Salvelinus confluentus in a Rocky Mountain Watershed, USA. PloS ONE 9: e Isaak & Hubert Nonlinear response of trout abundance to summer stream temperatures across a thermally diverse montane landscape. TAFS 133: Isaak et al Effects of climate change and wildfire on stream temperatures and salmonid thermal habitat in a mountain river network. Ecol. Appl. 20: Isaak et al A watershed-scale monitoring protocol for bull trout. GTR-RMRS-224. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. 25 p. Peterson et al Patch size but not short term isolation influences occurrence of westslope cutthroat trout above human made barriers. Ecology of Freshwater Fish. DOI: /eff Rieman et al Anticipated climate warming effects on bull trout habitats and populations across the interior Columbia River basin. TAFS 136: Rieman et al Have brook trout displaced bull trout along longitudinal gradients in central Idaho streams? CJFAS 63: Shepard et al Status and conservation of westslope cutthroat trout within the western United States. NAJFM 25: Wenger et al Flow regime, temperature, and biotic interactions drive differential declines of trout species under climate change. PNAS 108: Wenger et al Role of climate and invasive species in structuring trout distributions in the Interior Columbia Basin, USA. CJFAS 68: Young et al DNA barcoding at riverscape scales: assessing biodiversity among fishes of the genus Cottus (Teleostei) in northern Rocky Mountain streams. Molecular Ecology Resources 13: