Mugu Lagoon

GENERAL			Source
Site	Mugu Lagoon
Map	Point Mugu 7.5' USGS quadrangle
Location	The lagoon is located within Naval Air Weapons Station, Point Mugu, 8 miles southeast of the City of Oxnard, in Southern Ventura County. The lagoon has three sections: the western arm, eastern arm, and central basin.
Contacts	Naval Air Weapons Station, Point Mugu, (805) 989-8094
Approximate Wetland Acreage	1,474		3
Approximate Historic Acreage	3000		7
Ownership	Owner	Acres	Source
	U.S. Navy	1,474	1
LAND USE			Source
Land Use Designation	The lagoon is within a Naval Air Weapons Station (NAWS); the City of Oxnard 2020 General Plan provides no other designation.		17
Onsite Use	NAWS is a major center for weapons systems testing and evaluation. Stewardship of the lagoon is a high priority in the course of NAWS operations, and access to the lagoon is severely restricted. The central and eastern arms are within the Santa Monica Mountains National Recreation Area (SMMNRA) but remain under Navy control.		1, 3, 12, 18
Historic Use	Supported a relatively dense native american settlement until the late 1700's, when Spanish missions were established. The surrounding area was used for ranching and agriculture during the1800's and 1900's; Calleguas Creek was channelized and its flows diverted to the lagoon in 1884. Duck clubs and a camping resort were developed in the 1920's and 30's. Naval operations began in 1945, with much of the facility built on fill.		1, 3, 2
Adjacent Use	The lagoon is surrounded by a major weapons testing facility containing hundreds of buildings, airstrips, and more than 50 aircraft. The Weapons Station is primarily surrounded by agriculture and open space, including two duck clubs to the northwest, and Point Mugu State Park and the SMMNRA to the east. Immediately offshore is a State Area of Special Biological Significance.		1, 7, 17
Historic Adjacent Use	Native American settlements were well established along the coast until the late 1700's. The area inland of the lagoon was used for ranching during the 1800's, and agriculture in the 1900's. The nearby watershed remains predominantly agricultural.		1, 2, 7
HYDROLOGY			Source
Tidal Influence	The tidal connection is through an inlet in the barrier beach, which migrates seasonally. The tidal prism is described as large relative to the volume of water remaining in the lagoon at low tide. The maximum tidal range for the central basin is about 6 feet; ranges are smaller in the "arms". The western arm is connected to the central basin through two culverts under Laguna Road and the eastern arm is connected through tidal channels.		1
Watershed Area	343 sq miles		7
Tributaries and Flow	Tributary	Flow	Source
	Calleguas Creek	Perennial flows are from NPDES permitted discharges, runoff, and irrigation return flows; in 1989, the 10-year peak flow was estimated to be 11,810 cfs into Mugu Lagoon. The creek is leveed with either rip-rap or earthen banks with a soft bottom through much of the Oxnard Plain; some of the upper reaches are concreted.	1, 7
	A series of 7 ditches that drain nearby agricultural fields and parts of the naval station, empty into the central basin and western arm.	No data located	1
Dams	None
Other Sources	Groundwater		1
WATER QUALITY			Source
General	High concentrations of banned pesticides are found in the sediment and biota; the lagoon is included in the 1996 list of impaired water bodies; selected criteria exceeded for sediment and tissue toxicity. Amphipod survival of sediment toxicity tests ranged from poor to fair. Designated Beneficial Uses: Nav, Rec1, Rec2, Comm, Est, Mar, Wild, Biol, Rare, Migr, Spwn, Shell, and Wet.		8, 9, 4, 21
Dissolved Oxygen (DO)	Monthly surface samples taken Semptember - November 1993 at 14 to 27 sites in the lagoon and tributaries. Time of sampling not specified. Dissolved oxygen concentrations ranged from 1.9 to 17.8 mg/l. Temperatures ranged from 12.6 to 24.9 C.		5
Water Salinity	Monthly surface samples September - November 1993 at 14 to 27 sites in the lagoon and tributaries. Time of sampling not specified. Concentrations ranged from 0.5 to 34.3 g/L (ppt). Low salinity readings came from stations in Calleguas Creek.		5
Sediment	1995 - average annual sediment yield from Calleguas Creek into the lagoon estimated to be 240,000 tons.		7
SOIL			Source
Soil	Soils and sediments are intermingled; sand, silt, and clay are found from the surface to depths of 85 to 135 feet.		1
Habitat	Acres	Vegetation
Open water	286.5	1981 - Diatoms, blue-green algae, macroscopic green algae - Enteromorpha and sea lettuce.	3
Tidal flats	128.4	1981 - Diatoms, blue-green algae, macroscopic green algae - Enteromorpha and sea lettuce.	3
Tidal creeks	39.5	1981 - Diatoms, blue-green algae, macroscopic green algae -Enteromorpha and sea lettuce.	3
Tidal marsh	943.5	1994 - Pickleweed, saltwort, saltgrass, iceplant*, Ca seablite, <i>Enteromorpha<i> green algae, and alkali heath were common among several areas surveyed around the lagoon. 1996 - Cordgrass and salt marsh bird's beak+ also present.	Ac. 3 Plants 1, 10
Salt pan	76.6	1984 - 1996 coyote bush, sand spurrey, big saltbush, and pickleweed listed as common.	Ac. 3 Plants 10
ANIMAL USE			Source
Birds	1979-1996 - 310 species included in a cumulative list for the area within 1km of the lagoon; of these 152 are water associated, including 32 sensitive species. Western snowy plover# (1996), light-footed clapper rail# (1995), Ca. least tern# (1994), and Belding's savannah sparrow# (1991).		11, 12, 14, 15, 16
Fish	1993 - Monthly September - November samples at 27 stations in the lagoon and tributaries using throw net, bag seine, minnow seine and dip net of 3.2 mm square mesh, collected 18 species. Topsmelt, Ca. killifish, mosquitofish, arrow goby, staghorn sculpin, and arroyo chub+ occurred most frequently; yellowfin goby* were observed but not collected. 1995 - one time summer sample did not find arroyo chub.		5, 6
Benthic Invertebrates	1994 - January samples at 51 stations in the lagoon, marsh and tributaries found 9 taxonomic groups; polychaetes, crustaceans, oligochaetes, insects, ribbon worms, and tube worms were most abundant. Arthropods, molluscs, and nematodes were also found. Ca hornsnail, olive ear snail, striped shore crab and yellow shore crab were the most abundant species found on the benthic surface. Method of sampling not described.		1
Insect	1994 - midges, shore flies, moth and sand flies, and long-legged flies were collected during January benthic sampling of 51 stations in the lagoon, marsh and tributaries.		1
Other Wildlife	1994 - January surveys of four areas in and around the marsh using small mammal traps and direct observation found 9 rodent species and evidence of coyote, red fox, opossum, raccoon, and feral dogs. Harbor seals (protected under the Marine Mammal Act) use the beach and sand bars near the lagoon mouth for hauling out and pupping.		1, 13
Special Status Species	1984-1996 - Pacific loon, ashy and black storm petrels, Amer. white and Ca. brown pelicans, double-crested cormorant, least bittern, white-faced ibis, fulvous whistling duck, harlequin duck, Barrow's goldeneye, osprey, bald eagle, No. harrier, Swainson's hawk, peregrine falcon, sandhill crane, long-billed curlew, laughing gull, Ca. gull, elegant tern, black tern, black skimmer, Xantus murrelet, rhinoceros auklet, long-billed savannah sparrow, tricolored blackbird,		11, 14, 15, 16, 5, 1, 13, 12
	Western snowy plover# (1996), light-footed clapper rail# (1995), Ca. least tern# (1994), Belding's savannah sparrow#(1991); 1996 - plants, saltmarsh bird's beak; 1993 - fish, arroyo chub (not found in 1995).
OUTLOOK			Source
Enhancement Status	The Navy has undertaken 3 wetland restoration projects since 1995, resulting in a total of 23.5 acres of tidal mudflat, sandflat, channels, ponds, salt marsh and sand islands; mitigation plans were being developed in early 1997 for restoration of a 37-acre site to predominantly salt marsh.		12
Watershed Management	Several studies focused on reducing flooding and sedimentation have led to installation of sediment control structures, stream bank stabilization projects, on-farm sediment basins, and adoption of range management practices. Local communities have also instituted grading and hillside erosion control ordinances. The interagency Mugu Lagoon Task Force was formed in 1990 to improve coordination of activities affecting the lagoon and to work towards its protection and enhancement. The task force participated in preparation of a 1995 erosion and sediment control plan for the watershed. In 1996 the Calleguas Creek Watershed Management Plan Committee began the task of identifying water quality issues, and formed technical subcommittees and developed guidelines for preparing a comprehensive watershed plan.		4, 7, 22
Pressure	Sedimentation, contaminated sediments, modified hydrology caused by land uses in the watershed, and flood control efforts affect habitat quality in the lagoon.		1, 14
SOURCES
1	PRC Environmental Management, Inc. 1996. Remedial Investigation Technical Memorandum, Installation Restoration Program, NAWS Pt. Mugu. 14 volumes. The study is the first part of a multi-phased effort, conducted pusuant to the federal Comprehensive Environmental Response, Compensation and Liability Act, to characterize the risks to human health and the environment posed by the release of hazardous substances in the course of Navy activities at NAWS Pt. Mugu. The memorandum reports the results of human health and ecological risk assessments conducted for eight areas on the Station. Assessments were based on surveys of geophysical, soil, sediment, surface water, and groundwater conditions, vegetative, benthic infauna and epifauna, fish, and mammal communities, and studies on tidal influence. Samples were collected in January of1994. Groundwater and sediments were tested for a variety of toxic constituents. (Only excerpts relating to the methods and results of biological samples, and the background and regional setting were viewed).
2	Swanson, M. T. 1994. From Spanish land grants to World War II: an overview of historic resources at the Naval Air Weapons Station, Point Mugu, California. 107 pp. Provides a detailed history of ownership and land use on the Naval Weapons Station property, from the time of the Spanish explorers to the U. S. entrance into World War II. It describes land disputes and local personalities, relates trends in crops grown and farm machinery used, and characterizes the influences of the railroad, coastal highway, and recreation. Historical features on the Station are also described.
3	Onuf, C. P. 1987. The ecology of Mugu Lagoon, California: an estuarine profile. U.S. Fish Wildl. Serv. Biol. Rep. 85(7.15). 122 pp. A synthesis and analysis of data on the structure and function of the Mugu Lagoon ecosystem. The regional geology, climate, and hydrology are summarized, as are the chemical constituents of the water. The effects of storms on the lagoonmorphology and the distribution and abundance of plants, invertebrates, fish, birds, herpetofauna, and mammals are described. The ecological relationships among these variables are analyzed and conditions compared to those of other coastal wetlands in the region
4	Los Angeles Regional Water Quality Control Board. 1995. Calleguas Creek preliminary report: state of the watershed. 46 pp. and appendix. This report summarizes available information on water quality within the Calleguas Creek watershed. The report was prepared to enable assessment of the potential cumulative impacts of individual permit requests as the Regional Water Quality Control Board makes the transition to managing water quality on a watershed basis. The level of detail varies, but existing surface, ground and imported water resources are described, as well as the variety of permitted point and nonpoint discharges. Water chemistry for various water bodies in the watershed are summarized and data on pollutant accumulation within the Point Mugu Naval Weapons Station is provided in some detail. Other ongoing watershed efforts are also briefly described.
5	Saiki, M. K. 1994. Survey of fishes and selected physicochemical variables in Mugu Lagoon and its tributaries, September-November 1993. 65 pp. and appendices. This document reports the results of fish surveys conducted to determine the status of the tidewater goby in Mugu Lagoon, and to examine the relationships among physicochemical conditions and the abundance and distribution of all species caught in the lagoon. Throw nets, bag seines, minnow seine and dip nets, all of 3.2 mm mesh, were deployed September-November 1993, at 27 stations in Mugu Lagoon and it's tributaries, and at 2 stations in the Santa Clara River estuary. Temperature, pH, DO, salinity, turbidity, and sediment particle size were also sampled. Stations in the Santa Clara River, where tidewater goby were known to be present, served as a check on sample methods and as a basis for comparison of habitat conditions. A series of scatter plots display relationships among various sediment and water quality parameters and occurrence of fish species. Appendices contain raw data and maps showing the stations where each species was caught.
6	Engle, J. M., K. D. Lafferty, J. E. Dugan, D. L. Martin, N. Mode, R. F. Ambrose, and P. T. Raimondi. 1995. Second year study plan for inventory of coastal ecological resources of the Northern Channel Islands, and Ventura and Los Angeles Counties. Prepared for the California Coastal Commission. 45 pp. A report on the progress and proposed plans for the second year of a monitoring program surveying selected rocky intertidal, soft bottom subtidal, sandy beach, and wetland areas of coastal Ventura and LA Counties, and the Northern Channel Islands. The discussion emphasizes program design and methods with some analysis of first year results. The LA/Ventura County portion focuses on wetlands, with fish, invertebrate, and bird surveys to be conducted at: Ventura and Santa Clara River estuaries, Ormond Beach, Mugu Lagoon Malibu Lagoon and Ballona wetlands. Other habitats will be characterized by samples at 20-30 additional sites. The study is being undertaken to enable an assessment of impacts in the event of an oil spill.
7	USDA Natural Resources Conservation Service. 1995. Calleguas Creek Watershed erosion and sediment control plan for Mugu Lagoon. 114 pp. and appendices. The report summarizes the condition of environmental resources in the Calleguas Creek watershed and describes the historical context for these conditions. It was prepared to identify and quantify erosion sources and sediment transport, and to inform development of a plan for addressing present and future erosion and sediment-related impacts. Biological and physical resources, geology, soils, and water quality are described at the watershed scale. Past, present, and projected land uses and associated flooding, erosion, sedimentation, and habitat problems are discussed. A series of alternatives for addressing these problems is forwarded, along with a recommended plan and implementation strategy. Resource information is derived from existing studies.
8	California Regional Water Quality Control Board, Los Angeles Region. 1994. Water quality control plan Los Angeles Region (4). 187 pp., plus appendices. The Los Angeles Regional Board's Basin Plan is designed to preserve and enhance the water quality and protect the beneficial uses of all regional waters. The plan designates beneficial uses and associated water quality objectives for inland surface waters, ground waters, coastal waters, and wetlands for the Los Angeles and Ventura Counties. It includes a discussion of applicable policies and statutory requirements, and identifies measures for achieving water quality objectives. It also describes ongoing monitoring and assessment programs
9	Los Angeles Regional Water Quality Control Board. 1996. Water Quality Assessment and Documentation. 106 pp. A list of waterbodies in the Los Angeles and Ventura County coastal watersheds that do not or are not expected to attain water quality standards after application of required technology-based controls. It includes a description of the methods and criteria used in the assessment. 303(d) lists are prepared as part of the Water Quality Assessment of the State's major waterbodies, and meet a requirement of Section 303(d) of the federal Clean Water Act.
10	Keeney, T. W. and J. Kameon. 1996. An annotated flora of Mugu Lagoon, California. 21 pp. A list of plant species (235) found in Mugu Lagoon and associated uplands between 1984 and 1996. Each entry indicates the location or communities in which the plant occurs and whether it is native, and provides a qualitative description of abundance.
11	Keeney, T. W. 1996. Checklist of birds of Mugu Lagoon and environs. 15 pp. List of birds seen within 1 km of Mugu Lagoon from 1979 - 1996. 310 species are listed.
12	Keeney, T. W.; Naval Weapons Station, Point Mugu. January 14, 1997. Personal communication (A report on the breeding success and population size of snowy plovers at NAWS Pt. Mugu 1993 - 1997 is planned for publication by the end of 1997.)
13	Hanan, D. A. and M. J. Beeson. 1994. Harbor seal, <i> Phoca vitulina richardsi<i> census in California, May-June, 1993. Prepared for NOAA Fisheries/National Marine Fisheries Service (NA27FX0273-01). 61 pp. including appendices. Presents the results of an annual aerial census of hauled out harbor seals along the entire California coast and the Channel Islands. The report includes a description of methods and a very brief discussion of results. The appendices contain counts from the 1993 census broken down by site, county, and by each of the Channel Islands. A table of total counts from previous surveys is also included.
14	Goodbred, S. L., D. B. Ledig, and C. A. Roberts. 1996. Organochlorine contamination in eggs, prey and habitat of light-footed clapper rails in three Southern California marshes. 32 pp. Presents the results of a study of organochlorine contamination at Mugu Lagoon and Seal Beach and Tijuana Slough National Wildlife Refuges. Contamination levels were measured in the sediment, shore crabs (a food source), and in rail eggs. Samples were taken 1989-1991. Data are presented only in narrative form. The discussion includes a comparison of data from each site in an effort to pinpoint contaminant sources and identify possible management actions to foster the species' recovery.
15	Caffrey, C. 1995. California least tern breeding survey, 1994 season. Prepared for the California Department of Fish and Game. (Bird and Mammal Conservation Program Report, 95-3) 49 pp. including appendix. This reports the results of the 1994 annual survey of California least tern breeding. Data were collected on the timing of reproduction activities, clutch size, site conditions, hatching success, and causes for failure, at all known California breeding sites (the most recent data provided from Point Mugu and Camp Pendleton was from 1992). The discussion considers statewide and site specific population trends over the years and provides an analysis of late season versus early season nesting pairs. Contributions to reproductive failure statewide and at particular sites is also discussed and recommendations for future study and management actions are included. Appendices provide supporting data tables.
16	U.S. Fish and Wildlife Service. 1991. A survey of the Belding's savannah sparrow in California, 1991. Report to the California Department of Fish and Game. 24 pp. and survey site maps. Report on a survey for territorial Belding's Savannah sparrow at 34 marshes between southern Santa Barbara county and the border with Mexico. Results are discussed within the context of previous years' data and recommendations are provided for further study and habitat improvements. The survey was carried out to provide an update on population data and to evaluate habitat conditions.
17	City of Oxnard. 1990. 2020 General Plan. Approx. 300 pp. The comprehensive long-term general plan for physical development of the area within the City's jurisdiction, or areas outside the City's jurisdiction which have bearing on its land use planning activities. It describes the current setting and presents findings, policies, and implementation strategies for growth management, land use, circulation, public facilities, open space /conservation, safety and noise issues. Biological information is based on existing information and provides few references.
18	Keeney, T. W. Undated. Natural Resources Management Objectives; Naval Air Weapons Station Point Mugu. 1 pp. excerpt. A statement of management objectives for the Natural Resources Management Program carried out by the NAWS Environmental Management Office at Mugu Lagoon and San Nicolas Island.
19	MacDonald, K. B. 1976. The Natural Resources of Mugu Lagoon. Coastal Wetland Series #17. 119 pp. and appendices. (Document was not cited in the profile) This report describes the natural resources of Mugu Lagoon and their condition, identifies surrounding land uses that affect them, and proposes measures for their protection and enhancement. Physical features, a brief human history, local and regional land use and ownership, and plant and wildlife communities, are described. This information is derived from existing studies. The report characterizes conflicting uses of these resources and identifies issues that should be considered in lagoon management. Appendices contain flora and fauna lists, a description of flood control alternatives for Calleguas Creek, plans and a memorandum of agreement between the Navy and U.S. Fish and Wildlife regarding management of the lagoon.
20	Pritchett, D.A.; US Fish and Wildlife Service, Ventura Field Office. March 1997. Personal Communication.
21	Biroski, S., California Regional Water Quality Control Board - Los Angeles. March 11, 1997. Personal communication.