North Bay steelhead: the historical record andimplications for restoration

Gordon Becker, Senior ScientistCenter for Ecosystem Managementand Restoration (CEMAR)

Outline• The fish. Quick review of steelhead (Oncorhynchus mykiss)

• Historical distribution/current status. Collecting, analyzing, and presenting fisheries information for Bay Area streams

• San Francisco Estuary Watersheds Evaluation. An intuitive, rapid technique to identify and guide restoration activities

• Steelhead passage and habitat projects. Developing “right fit” solutions in a “quick fix” world

• Big picture. Current limitations of the steelhead recovery process and the “Big 3” problems/opportunities

Key traits of steelhead• Two forms. Steelhead are anadromous, or ocean going;

resident rainbow trout can have a stream-only life cycle.

• Iteropary. Some SH spawn in more than year (kelts).

• Swimming performance. Power allows headwaters access.

• Environmental tolerance. Adapted to mediterranean climate, thus largest range of the salmonids.

• Plasticity. Depending on environmental conditions, steelhead can vary run and rearing in space and time.

Middle Fork Eel summer steelhead

Specific growth in the estuary was significantly greater than upstream habitats for 2003 and 2004 (t(501)=22.7, p<0.001, Figure 7 ). Mean growth in the estuary for 2003 and 2004 was 0.36% increase in FL per day, while mean upstream growth was 0.06% increase in FL per day for the same period. [Data from Scott Creek, Santa Cruz County]

Estuarine rearing

Bond, M.H. 2006. Importance of estuarine rearing to central California steelhead (Onocorhynchus mykiss) growth and marine survival. Master of Arts thesis, University of California Santa Cruz.

Steelhead distribution study goals

• Provide authoritative Oncorhynchus mykiss information resource

• Expand O. mykiss historical distribution and current status record

• Contribute to O. mykiss conservation and recovery planning

Steelhead distributionstudy approach

• Report for broad audience: text, tables, maps (and database in newer projects)

• Comprehensive information

• Transparent process of data mining

• Peer review

Estuary streams report results• Coho. Nine historical runs; now extirpated from region.

• Chinook. Nine streams with possible historical runs; now at least six streams with recurring runs.

• Steelhead/rainbow trout. 194 streams with historical definite use; now 134 (69 percent) streams with definite runs or populations.

• Oncorhynchus mykiss abundance. Reliable evidence of population decline in 158 streams (81 percent).

• O. mykiss anadromy. Anadromous life history possible in 19 watersheds (53 percent of historical SH watersheds) and 67 streams (35 percent of historical SH streams).

O. mykiss of Marin County streams

Historical “DF” 18

Current “DF” 17

Current ”DF"/

historical "DF"

94 percent

Marin County findings

• Arroyo Corte Madera del Presidio and Corte Madera Creek both productive, both heavily channelized

• San Anselmo Creek highest productivity in Corte Madera Creek watershed

O. mykiss of Sonoma County streams

Historical “DF” 27

Current “DF” 22

Current ”DF"/

historical "DF"

81 percent

Sonoma County findings

• Estimated run of 500 in 1965

• Best productivity likely in Carriger Creek and upper mainstem and headwaters tributaries (e.g., Stuart Creek)

O. mykiss of Napa County streams

Historical “DF” 44

Current “DF” 36

Current ”DF"/

historical "DF"

82 percent

Napa County findings

• Napa River system most important Bay Area steelhead resource: historical 6K to 8K average?; 1,200-1,300 in 1969?

• Best productivity in west-side tributaries like Redwood, Dry, and Sulphur creeks

O. mykiss of Solano County streams

Historical “DF” 6

Current “DF” 4

Current ”DF"/

historical "DF"

67 percent

Solano County findings

• Likely substantial Suisun Creek run until construction of Gordon Valley Dam (Lake Curry) in 1926

• History of calls for instream flow protection on Wooden Valley Creek

North Bay findings• O. mykiss remains in higher percentage

of No. Bay streams than Bay average

• Streams supporting anadromous life history populations greatly reduced

• Population decline in all streams

• Many reproducing isolated populations (i.e., run refreshing genome decreased)

Data findings

• Number of surveys per stream low

• Sampling, effort and information sharing problems limit O. mykiss understanding

• Recent (≤ ten years) information lacking

• Population features (e.g., density, year classes, abundance) rarely estimated; habitat characterizations unusable

Anchor Watersheds Rationale• Steelhead/rainbow trout populations. Reproduction

indicates functioning habitat.

• Substantial available habitat. Considered at a screening level, the rearing habitat accessible in a watershed restored through highly likely actions.

• Passage barrier programs. Barriers identified and subject of engineered designs to modify or remove them.

• Collaborative restoration planning. Watershed has a regulatory or stakeholder process to “drive” restoration.

• Land use controls. This criterion reflects the importance of watershed areas in public ownership or otherwise protected from adverse land use effects.

Next steps

Instream flow provisions. Reservoir releases or minimum flows based on availability study.

Limiting factors reviews lead to:Passage barrier modifications. Design informed

by hydrologic/geomorphic principles.

Land use improvements. Ideal of dedicated stream corridor and effective erosion control.

San Anselmo Ck, Corte Madera Ck watershed

Stuart Ck, Sonoma

Creek watershed

Ritchey Creek, NapaRiver watershed

Fish passage design

• Optimize passage using migration season 95 percent and 2 percent exceedence flows

• “Design” high flow at 10 percent annual exceedence (i.e., low end of in-migration flow)

• Minimum depth 0.8 feet for short reach only!!!

• Natural fishway over low flow (e.g., Denil)

Generalized watershed-level restoration planning

• Action Plan of necessary restorations

• Stakeholder process critical

• High quality information speeds progress

• Extra planning, extra $ for best designs

North Bay big picture issues

• Seasonal supply/demand dichotomy

• Land too valuable for riparian use

• Land in private ownership

• Last hope for region

Even bigger picture issues

• Without water conservation, growth remains the 800 pound gorilla

• Science to policy work needed (e.g., re: barriers, hatcheries, ESUs)

• Structural problems inhibit water and land use decision-making regarding steelhead

• Ultimately, all restoration is local

“Big 3” - #1, Barriers• Flood works and road crossings in lower

watershed, downstream from habitat - cost of right-of-way and free-span

• Major water supply features without fishways downstream from habitat - efficiency of large or low-flow ladders

• Dry season diversions strand and inhibit summer movement - long standing tradition with potentially costly fix

Barrier solutions

• Design fishways and channels to modern hydrograph

• Consider re-connecting up- and down- stream populations (e.g., trap+truck)

• Free-span

• Monitored off-stream storage

“Big 3” - #2, Sediment

• Jurisdiction/enforcement - “take” case hard; missing prosecutors

• “Non-point” - access and coverage issues

• Disregard/lack of understanding - poor logging, grading, encroachment practices

• Riparian area policy - Setbacks not enforced; revisions unsuccessful

Sediment solutions

• RWQCB process

• Re-establish riverine access

• Steelhead stream campaign

• Achieve setback consensus

“Big 3” - #3, Water

• Balance data - supply and demand information inaccurate and incomplete

• Instantaneous/annual over-appropriation: diversion (allowable + illegal) ≥ supply

• Groundwater - unregulated; hard to show “take”

• Fish flows - methods for setting rearing and migration flows sub-standard

Water solutions

• Metering and seasonal diversion control

• Water budget for critical streams

• Biologically based in-stream flows

• Groundwater and illegal diversion management program

• Make pigs fly