Steelhead Management in the Monterey Bay Region

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A watershed-related issue examined by the ENVS 560/L Watershed Systems class at CSUMB.


Overview

Steelhead present unique management challenges compared to other salmonids due to their life history plasticity. These management challenges are compounded because salmonids in the Monterey Bay Region are split into two Distinct Population Segments (DPSs): South-Central and Central California Coast Steelhead. A DPS is a population that is discrete and reproductively isolated from other populations [1]. Steelhead in the Monterey Bay Region face difficult environmental conditions because of the unique topography of the area, and proximity to the southern limit of the species range. Both DPSs in the Monterey Bay Region are currently listed as threatened under the Endangered Species Act (ESA).

Management Challenges in the Monterey Bay Region

There are two areas designated as critical habitat for steelhead in the Monterey Bay area.[2]. The Central California Coast Section extends from the Russian River south to Aptos Creek, and the South Central California Coast Section extends from the Pajaro River south to just north of the Santa Maria River, effectively splitting the Monterey Bay in half. Since the critical area spans across multiple cities and counties, different parties need to work together to manage the species.

Habitat in the Monterey Bay Region

The Monterey Bay, located on the Central Coast of California, is the centerpiece of the Monterey Bay National Marine Sanctuary. Steelhead in the Monterey Bay Region are of particular interest because they are near the southern limit of the species range, and face environmental conditions distinctly different from Northern California populations. The Mediterranean climate of the Monterey Bay Region results in temperatures that are typically higher than those found to the north, with mild winters and productive high-flow springs that support high growth rates [3].

In contrast, rainfall and stream-flow are low during the summer and fall, limiting growth rates. The small coastal streams of the Monterey Bay Region frequently feature sand-bar closed estuaries during low-flow periods that may provide ideal nursery habitat for smolts [4] [3], but also constrain potential emigration and return dates to when stream-flow is high enough to breach the sandbar [5].

Major steelhead habitats in the Monterey Region include:

A detailed list of steelhead habitat can be found in the Habitat Recovery plans for the North Coast and South Central Coast DPSs.

Population Decline Estimates

The population size of both the South Central Coast steelhead and the Central Coast Salmon are declining. Spawning runs of the Central Coast Salmon have declined by roughly 80-90% in the past 50 years. [8] The South Central Coast steelhead have faced similar declines with historical runs of 27,000 fish reduced to 500 by 1997. [9]

Steelhead once had a large run up the Salinas River, today the population is facing drastically reduced population sizes. Similarly Steelhead in the Salinas Watershed are also facing population size reductions. The Salinas Watershed encompass the Salinas River as well as many tributaries within the Central Coast.

Steelhead counts at the San Clemente Dam have also declined since a recorded peak of 800 fish in 1997.[10] By the end of April 2009, this number had decreased to 94. [11]

Conservation and Restoration Efforts

The National Oceanic Atmospheric Administration, National Marine Fisheries Service, and Southwest Fisheries Science Center [1] have been working closely with the Monterey Bay Salmon and Trout Project [2] on the restoration of Steelhead populations in the Monterey Bay Region. NMFS and MBSTP operate the Kingfisher Flat Conservation Hatchery outside Davenport, CA, in an effort to restore Steelhead populations and maintain the genetic diversity of local populations. Returning adult Steelhead are captured and spawned with both wild returning adults and with captive broodstock adults to ensure greatest possible genetic diversity. Yearlings are transported and released into rivers and streams in the Monterey Bay Region each fall.

The MBSTP also plays an important role in educating the local community about conserving salmon and steelhead populations. The group leads a Salmon and Trout Education Program [3]. Elementary through highschool aged students from areas across San Bruno to Gonzales are able to participate in MBSTP's program. Not only are the students educated on the salmonid life cycle and habitat requirements, but the students also raise steelhead in the classroom.[12] A similar program is being conducted by the Central Coast Salmon Enhancement [4] in the South Central Coast.

Recovery Plans

The Federal Endangered Species Act of 1973 mandates that recovery plans are developed and implemented for the conservation and survival of federally listed species. Two steelhead recovery plans overlap the Monterey Bay Region: Northern California and South-Central California populations.

Northern California

A full recovery plan for the Northern California DPS is still in development. The Northern California Steelhead DPS Federal Recovery Outline, released in 2007, serves as an interim guidance document until a full recovery plan is compiled and approved. The 2007 recovery plan outline contains a biological assessment, list of threats, conservation assessment, and a recovery strategy.

Some of the priority tasks identified to improve potential for recovery include:

  • Conduct and improve research and monitoring
  • Balance the water supply quota for fish recovery needs
  • Improve water quality by identifying and treating point and non-point source pollution
  • Reduce and control impacts from urbanization
  • Enhance riparian and aquatic habitat that are important for steelhead survival. Riparian habitat provides shade to the water, which helps limit high water temperatures. Riparian habitat also provides a food source for benthic invertebrates. These invertebrates are a food source for steelhead. Large woody debris also can provide habitat for steelhead.
  • Educate the water-user community and promote multi-use/recycling of water to help reduce water withdrawals. This will provide more water flow for steelhead habitat. It can also help reduce the likelihood the creek or stream runs dry during steelhead migration.

South-central California

The South-Central California Steelhead Recovery Plan was released in 2013. The goal of the recovery plan is to "recover anadromous steelhead and ensure the long-term persistence of self-sustaining wild populations of steelhead across the DPS – and ultimately to remove south-central California steelhead from the Federal List of Endangered and Threatened Wildlife". It includes a description of steelhead biology and ecology in general, as well as specific information on the land use, watershed conditions, and threats for each biogeographic population group withing the DPS. The plan outlines overall recovery goals, objectives and criteria and strategies to achieve those goals. Major watersheds in the Monterey Region of the Recovery Planning Area include the Pajaro, Lower Salinas, and Carmel Rivers.

Major threats in the Monterey Region include [7]:

  • Dams and surface water diversions
  • Groundwater extraction
  • Agricultural Development
  • Agricultural Effluent
  • Levees and Channelization

Some of the critical recovery actions for the Region include [7]:

  • Ensuring groundwater extractions provide essential habitat functions for adult and juvenile steelhead
  • Modify stream barriers to allow steelhead migration to upstream spawning and rearing habitsts (eg. Uvas Dam, San Clemente Dam, and Los Padres Dam)
  • Identify, protect, and restore estuarine and freshwater spawning and rearing habitats, such as managing sandbar breeching at the river's mouth and supplying spawning gravel and large woody debris within the lower mainstems.

Stakeholders

Spatial Data Resources

Links

References

  1. NOAA Fisheries, Date accessed March 29, 2017 http://www.nmfs.noaa.gov/pr/glossary.htm
  2. Central California Coast Steelhead http://www.westcoast.fisheries.noaa.gov/protected_species/salmon_steelhead/salmon_and_steelhead_listings/steelhead/central_california_coast/central_california_coast_steelhead.html
  3. 3.0 3.1 Hayes SA, Bond MH, Hanson CV, Freund EV, Smith JJ, Anderson EC, Ammann AJ, MacFarlane RB. 2008. Steelhead growth in a small central California watershed: upstream and estuarine rearing patterns. Transactions of the American Fisheries Society 137:114-128.
  4. Bond MH, Hayes SA, Hanson CV, MacFarlane RB. 2008. Marine survival of steelhead (Oncorhynchus mykiss) enhanced by a seasonally closed estuary. Canadian Journal of Fisheries and Aquatic Sciences 65:2242-2252.
  5. Satterthwaite WH, Beaks MP, Collins EM, Swank DR, Merz JE, Titus RG, Sogard SM, Mangel M. 2009. Steelhead life history on California's Central Coast: insights from a state-dependent model. Transactions of the American Fisheries Society 138:532-548.
  6. 6.0 6.1 6.2 2007 Federal Recovery Outline for the Distinct Population Segment of Northern California Steelhead
  7. 7.0 7.1 7.2 7.3 Federal Recovery Plan for the Distinct Population Segment of the South-Central California Coast Steelhead. 2013. National Marine Fisheries Services.
  8. http://caltrout.org/pdf/Central%20California%20Coast%20Steelhead.pdf
  9. http://www.westcoast.fisheries.noaa.gov/publications/recovery_planning/salmon_steelhead/domains/south_central_southern_california/2013_scccs_recoveryplan_final.pdf
  10. Appendix K: DETAILED LIFE HISTORY DESCRIPTIONS FOR FISH ACTION SPECIES
  11. http://www.mpwmd.net/asd/board/boardpacket/2009/20090521/21/item21.htm
  12. Monterey Bay salmon and Trout Project http://mbstp.org/General/aboutus.html

Disclaimer

This page may contain student work completed as part of assigned coursework. It may not be accurate. It does not necessary reflect the opinion or policy of CSUMB, its staff, or students.