Difference between revisions of "Potential watershed impacts on Elkhorn Slough"
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Scientific studies conducted on the watershed effects on Elkhorn Slough have considered runoff from human activities and other alterations of the upstream land and how it relates to the following: | Scientific studies conducted on the watershed effects on Elkhorn Slough have considered runoff from human activities and other alterations of the upstream land and how it relates to the following: | ||
Revision as of 23:22, 2 February 2011
Sedimentation and Contamination
A watershed-related issue examined by the ENVS 560/L Watershed Systems class at CSUMB.
Contents
Summary
The Carneros Creek Watershed that feeds into Elkhorn Slough has many important resources that benefit both humans and wildlife. Due to European settlement in and around the watershed, the natural connectivity of both fresh and salt water bodies has been disrupted. Development such as the cultivation of steep slopes for agriculture and the increase of residential structures and roads has caused major changes in water flow. In addition, human activities allow for the distribution of pollution and pathogens. Various organizations in the region as well as county, state and federal regulatory bodies continuously work to limit the damage to the watershed and the ecosystem that depends on its functions.
Location
Located just inland of Elkhorn Slough along the Central California Coast, water from the Carneros Watershed flows through Carneros Creek into the Slough. The Elkhorn Slough is located within the curve of the Monterey Bay one hundred miles south of San Francisco. The area is bounded by Watsonville to the North and Castroville to the South. Anthropogenic manipulation of the watershed has increased in recent years and is characterized by agricultural and residential development. Residential and agricultural development occurs throughout the Carneros Watershed, but sedimentation and pollution accumulates and the lower stream channels are the most impacted. The Elkhorn Slough Watershed Conservation Plan (1999), was created with intention of preserving the intact natural communities. The plan identified riparian forests in the lower Carneros Creek floodplain and upland ridges with unfragmented maritime chaparral in the Elkhorn Highlands as areas in need of protection and restoration. most of the rich farmlands are concentrated in the area called Springfield Terrace.
Resources at stake
The Elkhorn Slough is a biologically rich wetland system that provides habitat for migratory birds, rare plants species, and nursery grounds for fish. Coastal estuaries and wetlands are one of California's most threatened ecosystems. High priority resources:
- Coastal marsh: Less than twenty-five percent of California's coastal marshes remain intact. Migrant and resident birds such as the Great blue heron and snowy egret use the marsh areas as feeding and roosting habitat. A small breeding population of the endangered snowy plover was found along the shores of the marsh along with nesting pairs of Golden eagles and white-tailed kites and many other species.
- Riparian forest:
- Freshwater wetlands: The wetlands house numerous threatened and endangered species including the the Santa Cruz Long-toed Salamander, California Tiger Salamander, California Red-legged frog. these species depend on freshwater wetlands and pond habitats. Functioning wetlands also provide important services to the ecosystem by acting as filters to trap sediment and contamination.
- Maritime chaparral:
- Coast live oak woodlands:
- Native grassland:
- Water quality: increase of residential development and agricultural practices on steep slopes surrounding Elkhorn Slough have increased pathogens, chemicals, and nutrients in watershed waterways
- Stream physical structure: erosion caused by human activities has increased sedimentation and has altered or filled in natural waterways
Stakeholders
Many organizations are working to address threats to the valuable resources within the watershed and reverse the damage caused by development. These organizations include:
- Elkhorn Slough Foundation (ESF): a non profit organization concerned with the health, conservation, and management of Elkhorn Slough. ESF also provides educational opportunities (tours, interpretive literature, etc.) for the public [1].
- Elkhorn Slough National Estuarine Research Reserve (ESNERR)
- ALBA & Triple M Ranch: maintain sustainable farming practices on their lands and attempt to reduce erosion and pollution flow into downstream waters [2].
- Family and corporate farms
- Residents: Residents of Elkhorn Slough and residents of the surrounding watersheds
- County regulators
- US Fish and Wildlife Service (FWS): US FWS designated Elkhorn Slough as a Critical Habitat for the threatened California red-legged frog (Rana draytonii) [3] (Critical habitat regulations only apply to federal agencies.. important for this issue?)
- California Department of Fish and Game
- Audubon Society: Elkhorn Slough is listed by the National Audubon Society as a Globally Important Bird Area for migratory birds along the Pacific Flyway [4] Due to eutrophication of the Slough, bird food source supplies have decreased. This decrease may have a negative effect on Elkhorn bird populations.[5]
- Local businesses:dependent on fisheries, recreation and tourism associated with the watershed Moss Landing Harbor at the mouth of the Slough
Laws, policies, & regulations
The Natural Resources Conservation Service (NRCS) Elkhorn Slough Watershed Project aids farmers in soil conservation practices to reduce erosion and subsequent sedimentation of adjacent marshlands.
Residential development is strongly discouraged due to restrictive land use regulations. The Monterey North County Land Use Plan (LUP) designated much of the western portion of the watershed to be used for "Agricultural Preservation" or "Scenic and Natural Resource Recreation." In the Carneros Creek area and the Elkhorn Highlands, land use designation restrict residential development in wetlands, chaparral and ridge tops.
Monterey County has attempted to reduce watershed erosion by enacting ordinances that require permits to be obtained for land clearing, building, and grading. [6] Sediments from activities that require development permits in areas of highly permeable soil must be retained on site. Ways in which sediment may be captured include tools such as infiltration basins and percolation pits. In areas of impervious surfaces sediment from the development must be spread on a non-erodible vegetated area.[6] Government agencies have the authority to charge landowners fines if runoff is detected from agricultural fields.
Science
The natural process of sedimentation occurs when loose particles suspended in a stream are deposited along a barrier or a bank. However, when the number of suspended particles in a waterway increases, typically due to human activity, sedimentation occurs too quickly and alters or fills the waterway.
Scientific studies conducted on the watershed effects on Elkhorn Slough have considered runoff from human activities and other alterations of the upstream land and how it relates to the following:
- California sea otter: A study conducted by Miller et al. (2002) indicated an increase in seropositive Toxoplasma. gondii occurrence in sea otters in Elkhorn Slough. T. gondii is a parasitic pathogen with two life stages. When concerning California sea otters it is transferred from the first host(typically a felid and likely a domestic cat) through waterborne fecal matter that is carried downstream to Elkhorn Slough. T. gondii affects muscle and nerve tissue and has resulted in fatal brain infections of California sea otters.
- Steelhead: ...What scientific studies are or would be relevant / already completed?...
Tools
Denitrification and Decomposition model (DNDC) developed by a team from the University of New Hampshire and the Cooperative Institute for Coastal and Estuarine Environmental Technology (CICEET) offers a model that can help monitor runoff.[7] ...What analytical (e.g. modeling) tools were or could be used?...
Future research
...What knowledge gaps remain?...
...Suggest a CWSP MS thesis topic that could contribute to the issue...
...Suggest a topic for a hypothetical study that had unlimited resources...
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.
References
- ↑ About ESF http://www.elkhornslough.org/esf/index.htm
- ↑ ALBA wetland restoration http://www.elkhornsloughctp.org/reference/subissue_detail.php?SUBISSUE_ID=48&sort=MAIN_PUB&order=ASC
- ↑ FWS http://www.fws.gov/pacific/news/2001/2001-43.htm
- ↑ Audubon Society http://www.elkhornslough.org/conservation/why.htm
- ↑ Elkhorn Slough: Technical Report Series 2009:1 http://www.elkhornslough.org/conservation/why.htm
- ↑ 6.0 6.1 Erosion Control http://www.co.monterey.ca.us/building/docs/ordinances/Erosion_Control.pdf
- ↑ Modeling Nitrogen in Elkhorn Slough http://www.elkhornsloughctp.org/reference/subissue_detail.php?SUBISSUE_ID=8
- Elkhorn Slough Foundation, The Nature Conservancy. 1999. Elkhorn Slough Watershed Conservation Plan.
- Elkhorn Slough Restoration Policy and Economics Report. 2010
