Download Applying Reconciliation Ecology Concepts To Salmonid Habitat

Applying Reconciliation Ecology Concepts To
Salmonid Habitat Restoration And Enhancement
Mike Burke, Nick Nelson, Greg Koonce,
Manny DaCosta and Marty Melchior
Motivations
• Share experiences in planning and implementing
salmonid habitat enhancement in highly altered,
yet natural settings that are critically important
for conservation of salmonids.
• Use a pair of contemporary ecological
paradigms to frame the associated nuances and
complexities.
Outline
• Definitions
• Context
• Introduce Case Study
• Design Application
• Results – Habitat and Utilization
Definitions
Novel Ecosystem
(Seastedt et al. 2008):
•
Interactions between altered river systems and alien
species are resulting in unprecedented combinations of
species in habitat quite different from undisturbed habitat
•
‘In managing novel ecosystems, the point is to not think
outside the box, but to recognize that the box itself has
shifted.’
Reconciliation Ecology
(Rosenzweig 2003):
•
Practical approach to living with the new reality of these
ecosystems for which recovery may be unattainable or
even inadvisable
•
Manage these systems to provide desirable attributes, in
particular to conserve biodiversity and critical species
Application Context
Focused on Physical Habitat Improvement:
•
Interaction of the altered physical processes can be
similarly unprecedented
•
Nearly all habitat restoration effort is a direct application
of reconciliation ecology
•
WRT to stream processes and how they create, destroy
and maintain habitat, it is essentially important to not only
understand that the ‘box’ has moved, but also:
•
Is the box still moving?
•
In what direction and how fast?
•
What is left in the box to work with?
Case Study
Dry Creek:
•
230 mi2 watershed
•
150 years of impacts lead stream far from its state at time
of European contact
•
Chinook and coho salmon, steelhead trout
•
Critical resource for regional recovery of coho and
steelhead
•
•
Abundant cold water in late summer over gravel
substrate, rare for region (artifact of regulation)
Microcosm of overlapping alterations within a 14-mile
reach of stream downstream of dam
Legacy of Alteration
•
1850 - 1900: Deforestation and agricultural conversion
•
1910 – 1975: Instream gravel mining
•
Led to systemic incision (20’-25’), slowed by end of period
•
Disconnection of lateral habitats and floodplain
Legacy of Alteration
•
1980 - present: dam construction and regulation
•
Curtails sediment continuity and floods, elevates base flow
•
Veg encroachment, sequester alluvium, ‘channelization’,
•
Efficient at transporting available gravels
Current Function (what’s left and where’s it
going)
•
Laterally and vertically stable, minimal disturbance
•
limited lateral habitat creation/revitalization – limited refugia
•
limited recruitment of substrate and LWD
•
‘it’s stuck’ – not empowered or able to create new habitat
Current Function (what’s left and where’s it
going)
•
Highly efficient at transporting available sediment with
regulated hydrology
•
limited roughness, short substrate residence time
•
Deficit of riffle habitat
•
Poor quality pools: swift water, limited complexity and cover
Prescriptions
•
Disturbance!:
 thin overbank vegetation to enable recruitment of legacy
substrate and promote geomorphic change
 energy dissipation
Prescriptions
•
Sediment Augmentation:
 ‘seed’ riffles with sediment caliber that is better fit for
regulated hydrology,
 Energy breaks improve residence time for substrate
Prescriptions
•
Supplement LWD:
 Provide cover and complexity,
 Foster habitat development – scour and deposition
 Enhance substrate residence time
Prescriptions
•
Rejuvenate lateral habitats and floodplains:
 Backwaters, side channels, alcoves
 Adjust to present base level and hydrology
Feedback (so far)
•
Intensive monitoring of fish utilization
Feedback (so far)
•
Intensive monitoring of fish utilization
Feedback (so far)
•
Intensive monitoring of fish utilization
Summary Points
 Nearly all river systems are moderately to substantially altered from their predisturbance state, yet are essential for conservation of critical species.
 The paradigms of the novel ecosystem and reconciliation ecology are useful for
characterizing the realities of physical habitat enhancement planning and
implementation.
 In order to successfully achieve habitat enhancement objectives, it is necessary
to reconcile the history of alteration, current physical function and future
trajectory.
 Often, intervention is required to nudge the physical system towards a trajectory
that can sustain and replenish the habitat that is enhanced.
Applying Reconciliation Ecology Concepts To
Salmonid Habitat Restoration And Enhancement
Citations
 Moyle, P.B., 2013. Novel Aquatic Ecosystems: The New Reality for Streams in
California and Other Mediterranean Climate Regions. River Res. Applic., DOI
10.1002/rra.2709.
 Rosenzweig, M.L. 2003. Win-win Ecology: How the Earth’s Species Can Survive
in the Midst of Human Enterprise. Oxford University Press. Oxford.
 Seastedt, T.R, Hobbs, R.J, Suding, K.N. 2008. Management of Novel
Ecosystems: Are Novel Approaches Required? Frontiers in Ecology and
Environment 6: 547-553
Acknowledgements
 Sonoma County Water Agency, NMFS, CDFW