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BEAVERS ROLE IN CREATING AND MAINTAINING HABITAT IN CALIFORNIA’S ESTUARIES
Elijah Portugal Redwood Community Action Agency
Contributions: Joe Wheaton, Wally Macfarlane; Utah State University
Redwood Symposium Sept. 15th, 2016
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Elijah Portugal - Introduction
Projects Coordinator/Geomorphology/Hydrology- RCAAEducation
• 2014 MS. Geomorphology/Hydrology, Utah State University, Logan UT.
• 2008 BS. Fisheries Biology, Humboldt State University, Arcata, CA.
Background• Fish Habitat
• Watershed-scale erosion and sediment dynamics
• Beaver as ecosystem engineers, ‘partnering’ in a restoration context while mitigating for nuisance behavior
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Workshops On Beaver Restoration
Website: http://beaver.joewheaton.org/
Tons of other resources on the website:
Beaver Restoration Guidebook published by USFWS:
http://www.fws.gov/oregonfwo/ToolsForLandowners/RiverScience/Documents/BRG%20v.1.0%20final%20reduced.pdf
State of Beaver Restoration in California Workshop
SRF Conference, Davis CA March 29 –April 1, 2017
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Partnering with Beaver…in Estuary Restoration?
I. Introduction, overview and objectives
II. Estuaries, degradation and beaver extirpation
III. Beaver ecology & dam building basics
IV. Management, conservation & restoration planningI. Beaver Restoration Assessment Tool and Beaver Dam Analogs
V. Questions/Comments?
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How Does This Relate to Redwood Science?
ESTUARY BASICS
• Coastal, forested northern CA watersheds terminate in estuaries
• Dynamic depositional setting, complex network of salt, brackish and freshwater channels supporting a range of stream velocities and habitat types
• High Sediment supply and hydrology -> High rates of lateral migration, overbank flow and channel avulsion
• Wet (high water table), low gradient, wide valley bottoms: spruce, alder, willow dominant trees with salt tolerant shrubs, forbes and grasses also present. Redwoods on hillslopes
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ESTUARY BASICS
• Buffer between ocean and river (combat climate change)
• Benefit flood control, water quality
• Highly biologically productive, support highly variable aquatic, wetland and riparian habitat for endangered salmonids and other species
• SONCC Coho Recovery and numerous other studies identify loss of estuarine habitat and beaver trapping as factors leading to ESA listing (NMFS 1997)
• Geomorphic and ecological setting = Excellent beaver habitat!
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Estuary Degradation
Nationally - 2/3 of estuarine wetlands lost over last century / California - 91% of wetland habitat lost
Figures: SFEI San Francisco Estuary Institute & Aquatic Science Center
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Estuary Degradation
Diked, drained and leveed for ag., grazing and urban dev
Complex multithreaded planform, high water table, highly heterogeneous habitat
Simplified, single thread planform, water table drops , homogeneous habitat
Widespread estuary degradation took place in northern CA after beaver were largely extirpated and has coincided with decline of pacific salmonids in northern CA
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Beaver are Native to Coastal Northern California
• Lanman et al., 2013; Lundquist et al., 2013
– Evidence of historic beaver occupation:
– Mattole R. Estuary
– Klamath R. Estuary
– Humboldt Bay Tribs
– Mendocino Coast
– Other locations inland
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Beaver Nearly Extirpated from Coastal CA by early 1900’s
– Inaccurate range in CA originally est. in 1937 (Grinnell) and 1942 (Tappe) after beaver had been nearly extirpated
– Estuary beaver particularly vulnerable to maritime fur trade and Spanish missions late 1700’s and early 1800’s
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California Beaver on the Rebound
– Increasing evidence of past occupation and reestablishment in historic range
– Trapping pressure reduced, natural predation down
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Beaver as a Restoration Agent in California
I am going to talk a bit about beaver, restoration strategies using beaver and techniques to deal with nuisance behavior
• To do this, we need to: Know a bit about beaver biology/ecology
– Focus on their role as ecosystem engineers (dam building)
– Understand where in the landscape such strategies makes sense
From: www.ankn.uaf.eduFrom: http://wolfmaan.ca/wp-content/uploads/2011/10/beaver_lodges.jpg
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The Hope is…
• Beaver can
– Help us restore degraded streams, rivers and estuaries for a lot less $ than traditional methods and create a restoration model that increases local employment opportunities
– Promote dynamic behavior in streams & rivers that leads to better water quality, healthier ecosystems & higher biodiversity
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But Lets Not Forget They Can Be Pests!
• In residential areas they can cause flooding…
• They often block culverts, which can flood roads
• They can chop down our ornamental landscape trees
• They can make a mess of irrigation diversions
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II. Beaver Ecology And Dam Building
I. Bit of Beaver Biology
II. Why do Beaver Build Dams?
III. Beaver Ecology -> Eco-geo-hydro feedbacks
Bridge Creek © Wheaton From: http://www.howstuffworks.com/beaver-dam.htm
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A Habitat Generalist And Highly Adaptable • Lakes• Rivers and streams• Abandoned channels on
floodplains• Freshwater and Brackish
Wetlands
Pierre Côtacute
California Academy of Sciences
Slide from John Stella
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A Habitat Generalist And Highly Adaptable
Hood et al., 2012 – Skagit Bay Delta Estuary
Hood, W.G., 2012. Beaver in Tidal Marshes: Dam Effects on Low-Tide Channel Pools and Fish Use of Estuarine Habitat. Wetlands, 32(3): 401-410.
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Common Habitat Ingredients: Water + Trees
• Northern tundra and treeline range boundary: wood limitation
• Southern desert range boundary: perennial streamflow and/or wood limitation
• Updated distribution to include coastal CA and OR: See Lanmanet al, 2013
Wood limitation
Waterand/or wood
limitation
Slide from John Stella
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What Do Beaver Eat?
• Spring/Summer: herbaceous plants, incl. aquatic and riparian forbs, grasses, grains and row crops
• Fall/Winter: tubers, bark and cambium of cached woody plants
• Woody plants comprise ~85% of winter diet; ~15% of summer diet
Photo: C. Demers, SUNY-ESF
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A Beaver Food Cache……..
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‘Central Place’ Foragers
• Forage from lodge
• Preferences depend on what is available (aspen, willow, cottonwood, alder)
• 100m or less from water
Nicola Plowes, ASU
Lodge
Lodge
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II. Beaver Ecology & Dam Building
I. Bit of Beaver Biology
II. Why do Beaver Build Dams?
III. Beaver Ecology -> Eco-geo-hydro feedbacks
Bridge Creek © Wheaton From: http://www.howstuffworks.com/beaver-dam.htm
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So Why Do They Build Dams?
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Aquatic Habitat Is Critical For Their Success
• Beaver more agile in water than on land; maximize time in the water
• Ponds provide cover from predators and foraging pathways
• Lodge includes underwater entrance, nest area above water
Photo by Anna M. Harrison
From: https://c2.staticflickr.com/6/5480/14429320108_de16bb8a94_b.jpg
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II. Beaver Ecology & Dam Building
I. Welcome & Objectives
II. Bit of Beaver Biology
III. Why do Beaver Build Dams?
IV. Beaver Ecology -> Important feedbacks
Bridge Creek © Wheaton From: http://www.howstuffworks.com/beaver-dam.htm
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Beaver Dams Trap Sediment -> Expand Riparian and Wetlands
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Pollock et al. 2007
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Beaver Dams can Change Hydrology
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Beaver Impacts on Fish?
Kemp et al. 2012
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Beaver Dams Benefit Endangered Salmonids
Bouwes et al., 2016 – Population level, watershed-scale increase in density, survival and production of juv. steelheaddue to natural and artificial beaver dams
NO IMPACT TO FISH MOVEMENT>35k steelhead tagged over 8 years with 4 stat ant. and yearly mobile surveys
Bouwes, N. et al. Ecosystem experiment reveals benefits of natural and simulated beaver dams to a threatened population of steelhead (Oncorhynchus mykiss). Sci. Rep. 6, 28581; doi: 10.1038/srep28581 (2016).
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Beaver Benefit Endangered Salmonids in Estuaries
LOTS of studies showing beaver ponds benefit salmonids in estuaries: (Rutherford 1964; Bustard and Narver 1975; Swales et al., 1986, 1988; Murphy et al., 1989; Keast and Fox, 1990; Baker and Hill, 2003; Pollock et al., 2004; Cooper, 2007; Hood 2012)
Habitat Benefits:
-Flow Refugia (Pollock et al., 2004)
-Increased Foraging Opportunities (Keast and Fox, 1990)
-Increased Size and Productivity (Bustard and Narver 1975;
Swales et al., 1986, Wallace, 2007, 2009)
-More Cover (Keast and Fox, 1990)
-Higher Over Winter Survival Bustard and Narver 1975; Swales et
al., 1986)
-Prevent Seasonal Floodplain Drying (Cooper, 2007)
From: Bouwes et al., 2016
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Management Conservation & Restoration Planning
I. Let’s not forget, they can be pests!
II. Living with Beaver?
III. Restoration by Rodents?
IV. Where? Meet the BRAT
V. Take Homes…
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Traditional Removal Methods Don’t Work for Long
• Dynamite and lethal removal largely: expensive, ineffective and lose benefits of beaver
• Boyles and Savitzky, 2008 -> Living with Beaver strategies less-expensive, more effective retain beaver benefits
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‘Living’ With Beaver Strategies…
• Is problem real or perceived?
• If real:
– ‘Beaver Deceivers’
– ‘Pond Levelers’
– ‘Caging’ trees
– All require $$ and maintenance
If those don’t work, live trap and relocation
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Some Guidelines For ‘Living’ With Beaver
Beaver Restoration Guidebook: http://www.fws.gov/oregonfwo/ToolsForLandowners/RiverScience/Documents/BRG%20v.1.0%20final%20reduced.pdf
Tippie, 2010
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Beaver Management Plans
• Balance the needs of landowners and the public with the benefits that beaver provide
• Common sense solutions to beaver nuisance behavior
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MANAGEMENT, CONSERVATION & RESTORATION
I. Let’s not forget, they are pests!
II. Living with Beaver?
III. Restoration by Rodents?
IV. Where? Meet the BRAT
V. Other Planning Tools
VI. Take Homes…
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Letting Beaver Do Restoration Is Not New• As early as 1930s, beaver used as
conservation tool
• In CA beaver relocated for erosion control 1923-1950 in 58 counties*
• Logic is simple… just take nuisance beaver and relocate them where we want their ecosystem engineering expertise
* “It is now understood that soil erosion and shortage of water in some places resulted from the destruction of the beavers which formerly built, and kept in repair, dams on the upper reaches of many streams.” – Donald Tappe CDFG 1942
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Popularity Growing Rapidly in CA
• Martinezbeavers.org - Heidi Perryman
• Occidental Arts and Ecology Center’s Water Ins. - Kate Lundquist and Brock Dolman
• Scott River Watershed Council –Betsy Stapleton, Charnna Gilmore
• Riverbend Sciences – Eli Asarian• Yurok Tribe• Rocco Fiori• Mid Klamath Watershed Council –
Will Harling• Sanctuary Forest• And others
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Yurok Tribe: Tributary to Klamath River Estuary
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At Least 6 Types of ‘Beaver’ Restoration
1. ‘Allow’ beaver to stay & promote/protect them (i.e. living with beaver)
2. Accidental beaver restoration
3. Transplant beaver from one area to an area where they are not currently & let them have at it
4. Riparian restoration & land use changes followed by transplanting beaver
5. In areas where beaver alone are not enough, help out with beaver dam analogues (BDAs), then hope beaver take over maintenance
6. Mimic beaver dam impacts with BDAs and artificially maintain…
Passive
Active
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A quick Interlude: What the heck are BDAs? Beaver Dam Analogs (BDAs)
I thought Beaver were supposed
to do the work???
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Beaver Dam Analogs (BDAs) -Complexes
Mimic the form and function of beaver dams, function together to achieve restoration objectives
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MANAGEMENT, CONSERVATION & RESTORATION
I. Let’s not forget, they are pests!
II. Living with Beaver?
III. Restoration by Rodents?
IV. Where? Meet the BRAT
V. Take Homes….
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BRAT: Beaver Dam Capacity Model
• Resolves where and at what level (within a drainage network) beaver dams can be built and sustained.
What’s the maximum # of dams this reach can support?
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http://brat.joewheaton.org
Two main components:1. Beaver dam capacity model2. Decision support and planning tools
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Take Homes: Opportunities for Beaver-Assisted Estuary Restoration
• Beaver are native to California’s estuaries
• Beaver are keystone species, profoundly influence the type and distribution of aquatic, wetland and riparian habitat
• Beaver create off-channel habitat critical to the recovery of coho and other salmonids
• We can mimic natural beaver dams with BDAs
• Natural and artificial beaver dams don’t make sense everywhere use BRAT and other tools to prioritize beaver-assisted restoration
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Acknowledgements
• Joe Wheaton (USU/ETAL)
• Wally Macfarlane (USU/ETAL)
• Nick Bouwes (ELR/USU)
• John Shivik (USFS/UDWR)
• Kent Sorenson (UDWR)
• Dan Keller (UDWR)
• Michael Pollock (NOAA)
• Mary O’Brien (GCT)
• Jordan Gilbert (USU/ETAL)
• Chris Jordan (NOAA)
• Carol Volk (SFR)
• Nick Weber (ELR)
• Nate Hough-Snee (USU/ETAL)
• Martha Jensen (USU/ETAL)
• Kenny DeMeurichy (USU/ETAL)
• Ryan Lokteff (USU/ETAL)
• CHaMP Field Crews
• Tim Beechie (NOAA)
• And many others…
Countless field crews & collaborators
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Questions/Comments??
Let us do what we do best to
restore endangered
species!