Juvenile salmon use of estuaries Functional performance of restoring and natural habitats Ecological effects of shoreline modifications.

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1 Juvenile salmon use of estuaries Functional performance of restoring and natural habitats Ecological effects of shoreline modifications Jason Toft

2 Jason Toft It s my birthday!

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4 CMR GPR GPC PA P2AR NC RIR RIA DIR SIR BIA MIA VCIR LMTRSMSAUMTA PIWR LSA Density (#/m 2 ) Petaluma River Napa River Suisun Bay West Delta San Joaquin Delta Sacramento Delta

5 Fish Distribution, Abundance, and Behavior at Nearshore Habitat Types in Puget Sound, WA, USA Jason Toft Wetland Ecosystem Team School of Aquatic and Fishery Sciences University of Washington Seattle, WA, USA Charles Simenstad Jeff Cordell Lia Stamatiou Funded by the Seattle Public Utilities Department

6 PACIFIC SALMON ECOSCAPE, Puget Sound denoting freshwater, estuarine and nearshore habitat continuum Adapted by C. Simenstad from an original illustration by the GIS & Visual Communications Unit, King County Department of Natural Resources

7 THE WATERSHED-ESTUARY-NEARSHORE CONTINUUM Adapted by C. Simenstad from an original illustration by the GIS & Visual Communications Unit, King County Department of Natural Resources

8 THE WATERSHED-ESTUARY-NEARSHORE CONTINUUM with watershed and shoreline development Adapted by C. Simenstad from an original illustration by the GIS & Visual Communications Unit, King County Department of Natural Resources

9 Puget Sound Nearshore

10 Riparian vegetation in estuarine habitats

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12 Negative impacts of shoreline modifications: - Degrading of intertidal habitat and shoreline vegetation - Discontinuity in aquatic-terrestrial interface - Sediment supply cut-off - Reflecting wave energy, increasing erosion and coarsening sediments

13 FUNCTION OF ESTUARIES IN SUPPORT OF JUVENILE SALMON Migration Corridor gateway between watershed to ocean life histories Physiological Transition salinity gradient allows physiological adaptation Foraging sharp transition in prey organisms Refuge from Predation shallow water, turbidity and structural features that provide refuge from predators Source: C. Simenstad, WET/SAFS/UW

14 VARIABILITY IN ESTUARINE AND NEARSHORE DEPENDENCE BY PACIFIC SALMON high dependence low dependence ocean type chinook chum ocean type coho (?) pink stream type chinook stream type coho sockeye Source: C. Simenstad, WET/SAFS/UW

15 Salmon Species with Juveniles utilizing the nearshore: Chinook (Endangered) Coho Chum Pink, Sockeye, Steelhead trout, Cutthroat trout, bull trout Issues of Hatchery versus Wild fish

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18 Historical Perspective Increased urban development leading to the degradation of natural habitats % of the current shoreline is modified by retaining structures. Chinook Salmon listed under the Endangered Species Act. Nearshore important to juvenile salmon as a rearing and migration corridor to the ocean.

19 Major River Alterations

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21 The Duwamish River Estuary historically

22 HISTORIC DREDGING AND FILLING OF THE DUWAMISH RIVER ESTUARY HABITAT AREA (hectares) DUWAMISH RIVER / ELLIOTT BAY ESTUARINE HABITAT LOSS TIDAL SWAMPS % Change TIDAL MARSHES SHALLOWS AND MUDFLATS HABITATS GRAVEL- COBBLE BEACHES SANDSPITS RELATIVE LOSS (%)

23 Shoreline Mapping - Duwamish beach 5% other 2% vegetation 22% riprap 48% bulkhead 23%

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25 7 DUWAMISH RIVER ESTUARY RESTORATION SINCE 1988 C um ulative A rea (ha) Jan- 87 Jan- 88 COASTAL AMERICA Diagonal Marsh Jan- 89 Turning Basin I T-105 Federal Center S (GSA) Jan- 90 Jan- 91 Jan- 92 Jan- 93 Jan- 94 Jan- 95 1st Ave S Jan- 96 NRDA Turning Basin II Jan- 97 Jan- 98 Hamm Creek Herring's House Duw amish Waterw ay Park Jan- 99 Jan- 00 COMMUNITY Kenco Marine North Wind's Weir Puget Creek Jan- 01 Jan- 02 Jan- 03 Site One Jan- 04 Jan- 05 Date Completed

26 COMPLETE AND ANTICIPATED DUWAMISH RIVER ESTUARY PROJECTS T ac Herring s House 1.8 ac Puget Cr. 0.2 ac Diagonal Marsh 0.4 ac Fed. Center S. (GSA) 0.3 ac 1 st Ave. S. Bridge 2.1 ac Duwamish Waterway Pk. >0.1 ac Hamm Cr. 3.0 ac Kenco Marine 0.7 ac Turning Basin Phase II 1.3 ac Turning Basin Phase I 0.4 ac North Wind s Weir 1.0 ac Site One 2.5 ac

27 Study design natural vs. modified vs. vegetated riprap Q: How do isolated patches of natural nearshore habitat differ from extensively modified reaches?

28 Preliminary results beach seining 2004 mean fish abundance mean fish taxa richness p < p < 0.05 p < p < 0.05 riprap vegetated Herring Kellogg Malarkey Hamm Statuary Herring Kellogg Malarkey Hamm Statuary paired t-test, t test, 2-sided, 2 n = 5

29 Main Objective: Quantify the abundance and behavior of juvenile salmonids and other fishes directly along marine shoreline habitat types.

30 Sampling Techniques Typical beach seines can be problematic better for quantifying directly along shore Enclosure Nets Snorkel Surveys

31 Sampling Methods: High tides 5/12-8/1/03 Spring Tides: Enclosure nets and snorkeling - sand, cobble, riprap Neap Tides: Snorkeling - all sites

32 Fish Densities: Between cobble beaches, sand beaches, and rip-rap that ends at the high intertidal, we see minimal differences - all in bottom fishes. Enclosure Nets: Flatfish (juv. English Sole) at Sand Beaches Fish Density (#/m 3 ) * Juvenile Salmon Forage Fish Other Nearshore Fishes Surfperches Flatfish Other Demersal Fishes Gunnels Crabs 0 Cobble Beach Sand Beach Rip-Rap

33 Fish Densities: Between cobble beaches, sand beaches, and rip-rap that ends at the high intertidal, we see minimal differences - all in bottom fishes. Snorkeling: Crabs at Cobble Beaches, Sculpins at Rip-Rap Fish # / (Secchi depth(m)*transect length(m)) Cobble Beach Abundant Fish Sand Beach Rip-Rap Juvenile Salmon Forage Fish Surf Perches Other Fish Fish # / (Secchi depth(m)*transect length(m)) * * Cobble Beach Less Abundant Fish Sand Beach * Rip-Rap Other Nearshore Fishes Flatfish Other Demersal Fishes Gunnels Crabs Unknown Fish

34 Fish Densities: When shoreline modifications extend into the subtidal, we see more differences - in pelagic fishes. Snorkeling: Overall at Overwater and Deep Rip-Rap, Juvenile Salmonids at Overwater, Surfperches at Deep Rip-Rap Fish # / (Secchi depth(m)*transect length(m)) Abundant Fish * * * * Juvenile Salmon Forage Fish Surf Perches Other Fish 0.0 Cobble Beach Sand Beach Rip-Rap Deep Rip- Rap Overwater Structure

35 Fish Densities: When shoreline modifications extend into the subtidal, we see more differences - in pelagic fishes. Snorkeling: Other Nearshore Fishes and Gunnels at Deep Rip-Rap Fish # / (Secchi depth(m)*transect length(m)) * * * Cobble Beach Less Abundant Fish Sand Beach Rip-Rap * * Deep Rip- Rap Overwater Structure Other Nearshore Fishes Flatfish Other Demersal Fishes Gunnels Crabs Unknown Fish

36 Salmon Densities and School Sizes: When shoreline modifications extend into the subtidal, we see differences in juvenile salmonids. Snorkeling: Juvenile Salmonid species groupings at Overwater and Deep Rip-Rap, also greater school sizes at Overwater (numbers above bars) Fish # / (Secchi depth(m)*transect length(m)) Cobble Beach 7 Sand Beach 8 Rip-Rap * 12 Deep Rip- Rap * * * * 44 Overwater Structure Other Salmonid Groupings Chum Chinook/Chum Chinook/Coho Chinook

37 Fish Location: Juvenile salmonids found 70% > 1m away from edge, or 30% at edge, rare underneath Overwater Structures.

38 Habitat Measurements: Shoreline modifications truncate the shallow water zone, gradual slope is lost. Pelagic fish that are typically spread-out along a large area may be forced to inhabit deep water directly along shore.

39 Cobble Beach low tide Sand Beach Rip-Rap Deep Rip-Rap Overwater Structure

40 Diet Analysis: Gastric lavage of juvenile chinook shows less terrestrial/riparian input (insects) at sites with retaining structures at intertidal or supratidal. 100 Other 80 Terrestrial Riparian % IRI Supralittoral/Marsh Plant Matter 20 Marine Planktonic/Neritic 0 Unretained (n=26) Retained - Supratidal (n=13) Retained - High Intertidal (n=40) Marine Benthic/Epibenthic

41 Common Juvenile Chinook Prey Items: INSECTS: Chironomidae Amphipods, Corophium sp. Worms: Polychaete Crustacea: Crab larvae Photo Credits: Jeff Cordell

42 Chironomid Life Cycle * Aquatic/Terrestrial Interface * Adult Chinook Feeding Pupae Egg Larvae

43 Prey Resources: Unretained shorelines have a greater input of terrestrial insects into the diets of juvenile chinook salmon.

44 Timing and Size: As compared to Lake Washington: juvenile chinook avoid armored banks. Juvenile chinook are larger and more pelagic in marine waters, less dependent on shallow water. Differences are related more to indirect rather than direct effects of shoreline modifications, such as changes in water depth, substrate, and shoreline vegetation. Sum Density (#/m 3 ) /19 6/2 6/16 6/30 7/14 7/28 Date Chum Coho (unmarked) Coho (marked) Chinook (unmarked) Chinook (marked) Forklength (mm) /19 6/3 6/18 7/3 7/18 8/2 Date Coho - marked Coho - unmarked Chinook - marked Chinook - unmarked Chum

45 Seahurst Park: Just completed! Remove Rip-Rap and restore intertidal zone, with linkages to riparian habitat

46 Olympic Sculpture Park: Planned to start this year Create intertidal and linkages to riparian habitat

47 Olympic Sculpture Park: Planned to start this year

48 Future Seawall Repair: Replace degraded planks, Gribbles! Opportunity to incorporate better materials and designs to improve habitat. Seattle Waterfront Falling to Gribble Invasion John Roach for National Geographic News April 23, 2004 Flea-sized crustaceans with seven sets of legs, four moving mouth parts, and a voracious appetite for wood-borne bacteria could cause the edge of downtown Seattle, Washington, to slip into the Puget Sound.