Factors Limiting Salmonid Production

The sustainability of anadromous salmonid populations depends upon habitat conditions. Each freshwater life stage (returning adults, embryos and alevins within redds, juveniles, and smolts) encounters a series of environmental features or processes that provide suitable, less-than-desirable, or unusable habitat. Essential habitat requirements are known as "limiting factors." Limiting factors are a group of related environmental factors that, if at sub-optimal levels, will prevent an organism from reaching its full biotic potential (Lincoln et al. 1998). The following sections identify and describe some of the limiting factors in freshwater and estuarine areas that are common to San Mateo and Santa Cruz Counties. These factors include:

This list is not exhaustive of all factors limiting salmonid production, and each listed here is only generally discussed on the following pages. Much of the detailed information about limiting factors in San Mateo and Santa Cruz Counties is contained in watershed assessment reports that address all the limiting factors for a given watershed or geographic area, and include recommended measures for mitigating these factors and restoring habitat and stream processes. These watershed assessments / plans are listed below and, where available, are linked to PDF files. Additional references are also listed with each limiting factor discussed on the following pages.

Watershed Assessments and Plans Addressing Limiting Factors

Aptos-Soquel

Conrad, M.T., and J. Dvorsky. 2003. "Aptos Creek Watershed Assessment and Enhancement Plan." Coastal Watershed Council and Swanson Hydrology and Geomorphology. 101 (plus appendices) pp.

Habitat Restoration Group. 1990. "Soquel Lagoon Management and Enhancement Plan." Prepared for City of Capitola, Santa Cruz County, California Coastal Conservancy, California Department of Fish and Game, 67 (plus appendices) pp.

Davenport

Smith, J.J. 1990. "The Effects of Sandbar Formation and Inflows on Aquatic Habitat and Fish Utilization in Pescadero, San Gregorio, Waddell and Pompinio Creek Estuary/Lagoon Systems, 1985-1989." Department of Biological Sciences, San Jose State University.

Snider, B., K.A.F. Urquhart, and D. Marston. 1995. "The relationship Between Instream Flow and Coho Salmon and Steelhead Habitat Availability in Scott Creek, Santa Cruz County, California." CDFG, Environmental Services Division, Stream Flow and Habitat Evaluation Program. 49 pp.

Half Moon Bay

Phillip Williams & Associates Ltd., Habitat Restoration Group, Prunuske Chatham Inc., and Callander Associates. 1996. "Pilarcitos Creek Restoration Plan." 172 pp.

Pescadero

San Gregorio

San Lorenzo

County of Santa Cruz Water Resources Program Environmental Health Services and Planning Department. 2001. "Draft San Lorenzo River Watershed Management Plan Update."

Dvorsky, J., D.W. Alley, and J.J. Smith. 2002. "Final Report, San Lorenzo River Salmonid Enhancement Plan." D.W. Alley and Associates and Swanson Hydrology and Geomorphology. Prepared for Santa Cruz County Environmental Planning Department, 115 (plus appendices) pp.

Watsonville

Fall Creek Engineering Inc., Buchanan Associates, Swanson Hydrology and Geomorphology, and John Gilchrist & Associates. 2002. "Lower Pajaro River Enhancement Plan for Green Valley, Casserly, Hughes,Tynan, Coward and Thompson Creeks, Santa Cruz County, California."

Swanson Hydrology and Geomorphology, Biotic Resources Group, Dana Bland & Associates, Hagar Environmental Sciences, and VB Agricultural Services. 2003. "Watsonville Sloughs Watershed Resource Conservation and Enhancement Plan."

Other

CDFG Stream Habitat Reports (pending) for Scott Creek, Mill Creek, Gazos Creek, Waddell, San Vicente, Little Creek, Big Creek, Henry Creek, West Wadell, East Waddell, Last Chance Creek.

Peninsula Open Space District. 1998. "Cloverdale Coastal Ranch Plan 'Healing the Relationship of People and Nature.'"

US Fish and Wildlife Service (USFWS). 2003. Coho Salmon Species Profile [Web page] [cited 2003]. View on-line source.

US Geological Survey. 2000. Nonindigenous Fish Distribution Information, Species List, Oncorhynchus kisutch [Web page] [cited 2003]. View on-line source.

Zatkin, R. 2001. "Compendium of California Department of Fish and Game Information about San Mateo County Coastal Streams." Compiled for The Committee for Green Foothills. Thirteen Volumes. (This set is organized by watershed and is available at the following local libraries: Half Moon Bay Library, San Mateo County Library System; Water Resources Center Archives, UC Berkeley; Science and Engineering Library, UC Santa Cruz; and United States Geological Survey Library, Menlo Park.)

Reference

Lincoln, R., G. Boxshall, and P. Clark. 1998. A Dictionary of Ecology, Evolution, and Systematics. Second Edition. Cambridge, UK: Cambridge University Press.