The Shiraz model A tool for incorporating anthropogenic effects and fish habitat relationships in conservation planning

Transcription

1 The Shiraz model A tool for incorporating anthropogenic effects and fish habitat relationships in conservation planning Mark D. Scheuerell National Marine Fisheries Service Seattle, WA

2 Acknowledgments Ray Hilborn (UW) Mary Ruckelshaus (NMFS) Krista Bartz (NMFS) Kerry Lagueux (NMFS) James Battin (NMFS) Hiroo Imaki (NMFS) Andy Haas (Snohomish Co.) Kit Rawson (Tulalip Tribe) Curt Kraemer (WDFW) Muckelshoot Tribe UW PRISM Project Puget Sound Technical Recovery Team Snohomish Basin Salmonid Recovery Technical Committee

3 An early view of the salmon life cycle Adults Smolts Eggs Parr Ocean Freshwater

4 Wide range of impacts Exotic species Climate change The 4 H s Marine-derived resources

5 An expanded view Human influence Atmosphere Adults Adults Eggs Ocean Smolts Smolts Parr Freshwater

6 The Shiraz model framework Land use Hatcheries Habitat Landscape processes Life-cycle model Climate change Hydropower Harvest Shiraz Scheuerell et al. (2006) CJFAS

7 Multistage Beverton-Holt model (Moussalli & Hilborn 1986) N s + 1 = 1 p + N s 1 c N s N s = individuals alive at life stage s p productivity = max. survival rate from s to s+1 c capacity = max. N producible at s+1

8 Key model attributes In general... Freshwater survival driven by the effects of habitat c determined by quantity of habitat p determined by quality of habitat Also assume Freshwater survival is density-dependent Marine survival is density-independent

9 Relate life history to habitat Stage 1 Habitat Stage 2 Habitat Stage 3 Space

10 Evaluating recovery strategies Snohomish River basin in Puget Sound selected as a test case for evaluating recovery strategies Contains 2 of 22 populations of Puget Sound Chinook salmon listed as threatened under ESA Collaborative effort between scientists and policy makers Used scenarios to compare possible policy outcomes to current and historical conditions

11 Snohomish River basin Snohomish 5 Skykomish Snoqualmie 2

12 Fall Chinook salmon Ocean type life history freshwater Parr rear briefly in creeks & rivers (year t+1) Adults return to spawn & die in the fall (year t) Smolts emigrate in May- July (year t+1) Adults at sea (years t+2 to t+5) ocean

13 Reduction in spawner capacity Legend 0% 1 10% 11 20% 21 30% 31 40% (Sanderson et al., NMFS, unpublished data)

14 Reduction in juvenile capacity Legend 0% 1 20% 21 40% 41 60% 61 80% % (Krista Bartz & Kerry Lagueux, NMFS, unpublished data)

15 Shiraz Outputs Calculations Inputs Action Class Variables Mechanistic model in Snohomish Riparian Forest Artificial Barriers Off-channel Habitat Edge Habitat Habitat Structures Forest Cover Impervious Surface Road Density Capacity at stage s+1 (c s+1 ) Pre-spawning Temp Incubation Temp Peak Flows Fine Sediment Abundance of stage s (N s ) Bartz et al. (2006) CJFAS Survival from stage s to s+1 (p s ) Abundance of stage s+1 (N s+1 )

16 Putting the pieces together For productivity temperature Egg Fry peak flows sediment temperature Smolt Adult

17 Putting the pieces together For capacity Egg Fry Smolt channel structure edge habitat estuary connectivity stream gradient bank-full width riparian condition Adult

18 Incorporating hatchery production T S Hatchery Stock Life stage Releases Tribal Summer Fingerling 1,500,000 Fall Fingerling 200,000 State Summer Fingerling 1,000,000 Summer Yearling 250,000

19 Effects of harvest Rebuilding exploitation rate (RER) = 24% Actual ER = RER + e e ~ N(0,0.2)

20 Percent increase in spawners Model sensitivity analyses historical juvenile capacity historical spawner capacity fry-smolt s +10% egg-fry s +10% Entire basin Estuary Mainstem Lowland Headwaters Location of restoration action Scheuerell et al. (2006) CJFAS

21 Returning adults (1000s) Abundance & productivity 40 Historical 30 Test case Current Spawners (1000s) Scheuerell et al. (2006) CJFAS

22 E Puget Riverine Lowlands E Puget Uplands W Cascades Lowlands & Valleys N Cascades Lowland Forests N Cascades Highland Forests N Cascades Subalpine/Alpine Proportion Summarizing diversity Historic Current Test Scheuerell et al. (2006) CJFAS

23 Spatial structure Historical of spawners Test case Current 8400 Legend Scheuerell et al. (2006) CJFAS

24 The big picture Freshwater habitat Eggs Freshwater habitat Hatcheries Juveniles Harvest Hydrology Land use Landscape processes Climate change Ocean habitat Adults

25 Effects of climate change 2 Climate models Input: predicted CO 2 Output: air temperature meteorology Hydrology model Input: air temperature meteorology land cover land form Output: stream flow stream temp GFDL Hadley Battin et al. (2007) PNAS

26 Change in spawners (%) Climate effects in 50 years Current Test case GFDL Hadley Battin et al. (2007) PNAS

27 Shiraz summary It s a modeling framework Uses flexible life history Spatially explicit habitat characteristics Offers information on VSP criteria Basic structure can be simplified and adapted

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29 Essential Fish Habitat (EFH) Mandated by the 1996 re-authorization of the Magnuson- Stevens Act (Sustainable Fisheries Act) Intended purpose is to insure sustainable production of harvestable fish Different from critical fish habitat (CFH) as identified under the Endangered Species Act Difficult to quantify, especially for fish like salmon with complicated life histories

30 Essential Fish Habitat (EFH)

31 Essential Fish Habitat (EFH) Previous attempt concentrated on the big picture (e.g. Roni et al. 1999) Ocean is a big place and little is known about spatial distribution of salmon Concentration on freshwater habitat Examined the entire watershed as one unit Identified a need for a life-cycle approach that includes effects of habitat on various life stages

32 EFH in practice Concentrate on current conditions vs. possible restoration scenarios Given a problem, what can we do to minimize the effects of future impacts? Working definition EFH: necessary habitat likely to insure no further decline in spawner abundance

33 Model scenarios Parameterized to current path conditions Stochasticity from harvest, juvenile survival Model run for 50 years Mean spawner abundance from 100 simulations Examined effects of habitat loss on mean spawner abundance

34 Mean spawner abundance Little effect of spawner capacity baseline Spawner capacity lost

35 Mean spawner abundance Effect of juvenile habitat baseline Juvenile capacity lost

36 Mean spawner abundance Cumulative effects of habitat loss baseline Cumulative juvenile capacity lost

37 Mean spawner abundance Cumulative effects of habitat loss baseline 54% of sub-basins 12% of total capacity Cumulative juvenile capacity lost

38 Location of EFH in Snohomish Spawning & rearing Rearing only

39 Important points Not all areas equal in capacity and importance Spatial distribution of habitat important We can make inferences about location of EFH Treated both populations as one management unit (common estuary & lower reaches) Some identification of EFH dependent on active management Did not consider explicit upstream impacts on downstream regions