8
Coastal Wetlands: Multiple Management Problems in Southern California

Joy B. Zedler

San Diego State University

San Diego, California

INTRODUCTION

California's 1973 Coastal Act was one of the nation's earliest attempts to plan for the coexistence of multiple coastal users. However, lack of support from recent governors, budget cuts, and intense population pressure have eroded California's status as a leader in coastal zone management. Multiple uses are now resulting in multiple conflicts (see Attachment 8.1), and estuarine wetlands are particularly threatened. The federal government has shown little interest in California estuaries. In fact, only two have been included in the Environmental Protection Agency's National Estuary Program: San Francisco Bay and Santa Monica Bay, and only four of the 19 National Estuarine Research Reserves are on the Pacific Coast. Of these, Elkhorn Slough and Tijuana Estuary are in California. The limited interest in Pacific coast wetlands extends to research support as well. It has been suggested that management models can be based on East Coast research and relationships and then modified to fit the west coast (Sutherland, 1991). This idea needs to be questioned.

Southern California estuaries have several unique qualities. The estuaries are small and isolated. The variability of various environmental factors (annual rainfall, timing of rainfall, storm intensity, and stream flow) is very high. Catastrophic events have lasting impacts on coastal wetlands. For example, Mugu Lagoon (near Santa Barbara) recently lost 40 percent of its low-tide volume due to flood-deposited sediments (Onuf and Quammen, 1983). Periodic E1 Niño events raise sea levels and increase storm frequencies. Coastal dunes are sometimes washed into the estuaries, especially where stabilizing vegetation has been denuded. At Tijuana Estuary, the shoreline has retreated 300 ft since 1852, with major erosion during the 1983 El Niño storms (Williams and Swanson, 1987).

Hydrologic features are also unusual. Freshwater discharge greatly influences the accumulation of sand from long-shore sediment transport processes in southern California. Estuarine inlets have a tendency to close, and the size of the tidal prism determines their ability to stay open to tidal flushing. Where watersheds are highly modified (disturbed soils and vegetation), erosion and sediment inflows



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Environmental Science in the Coastal Zone: Issues for Further Research 8 Coastal Wetlands: Multiple Management Problems in Southern California Joy B. Zedler San Diego State University San Diego, California INTRODUCTION California's 1973 Coastal Act was one of the nation's earliest attempts to plan for the coexistence of multiple coastal users. However, lack of support from recent governors, budget cuts, and intense population pressure have eroded California's status as a leader in coastal zone management. Multiple uses are now resulting in multiple conflicts (see Attachment 8.1), and estuarine wetlands are particularly threatened. The federal government has shown little interest in California estuaries. In fact, only two have been included in the Environmental Protection Agency's National Estuary Program: San Francisco Bay and Santa Monica Bay, and only four of the 19 National Estuarine Research Reserves are on the Pacific Coast. Of these, Elkhorn Slough and Tijuana Estuary are in California. The limited interest in Pacific coast wetlands extends to research support as well. It has been suggested that management models can be based on East Coast research and relationships and then modified to fit the west coast (Sutherland, 1991). This idea needs to be questioned. Southern California estuaries have several unique qualities. The estuaries are small and isolated. The variability of various environmental factors (annual rainfall, timing of rainfall, storm intensity, and stream flow) is very high. Catastrophic events have lasting impacts on coastal wetlands. For example, Mugu Lagoon (near Santa Barbara) recently lost 40 percent of its low-tide volume due to flood-deposited sediments (Onuf and Quammen, 1983). Periodic E1 Niño events raise sea levels and increase storm frequencies. Coastal dunes are sometimes washed into the estuaries, especially where stabilizing vegetation has been denuded. At Tijuana Estuary, the shoreline has retreated 300 ft since 1852, with major erosion during the 1983 El Niño storms (Williams and Swanson, 1987). Hydrologic features are also unusual. Freshwater discharge greatly influences the accumulation of sand from long-shore sediment transport processes in southern California. Estuarine inlets have a tendency to close, and the size of the tidal prism determines their ability to stay open to tidal flushing. Where watersheds are highly modified (disturbed soils and vegetation), erosion and sediment inflows

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Environmental Science in the Coastal Zone: Issues for Further Research can greatly reduce tidal prisms. Increased freshwater inflows cause native salt marsh vegetation to be replaced by brackish invaders (Zedler and Beare, 1986). Finally, southern California has lost most of its coastal wetland habitat. In California as a whole, 91 percent of the wetland area (coastal plus inland) has been converted to other uses; this is the nation's highest loss rate (Dahl, 1990). On the coast, only about a fourth of the historic acreage is left, and much of it is in San Francisco Bay. Most of the 26 wetlands in southern California have some protection as habitat reserves. However, all have been reduced in size and are disturbed to various degrees. In the San Diego area, salt marshes have declined drastically. The acreage of tidal salt marsh in Tijuana Estuary, San Diego Bay and Mission Bay is only 13 percent of its historic area (San Diego Unified Port District, 1990). With all these habitat losses and damages, biodiversity is at risk. The state of California recognizes 10 coastal animal species as endangered or threatened with extinction (Department of Fish and Game, 1989). The California Native Plant Society considers 17 coastal wetland plants as rare. This paper discusses two problems in southern California, both of which have aspects that are unique to the region. The first concerns wastewater management. Because municipal water supplies are imported from well outside the region, the release of treated effluent to streams threatens the hydrologic regime of coastal rivers and downstream estuaries. The second problem is mitigation. The region lacks the sites that are needed for mitigation projects, and there are no proven methods for replacing habitats used by endangered species. The paper ends with a consideration of the adequacy of the research base for dealing with these issues. The Wastewater Issue The more than 100 estuaries along California's 1100-mile-long coast receive streamflows in pulses, due to the region's Mediterranean-type climate with winter rainfall and summer drought. Under natural conditions, it is likely that streams had minimal flow in summer. In the San Diego region, dams reduce winter streamflows, and wastewater discharges increase summer streamflows, to coastal estuaries. Filling to build roads across the estuaries has reduced tidal prisms and increased chances of inlet closure. In general, the impact of development has been to decrease tidal influence and increase freshwater inflow, both by increasing the volume of fresh water discharged to the coastal wetlands and by prolonging the period of stream flow. This region continues to grow very rapidly; more than 85,000 people moved to San Diego in 1987, and growth rates were just as high in 1988 and 1989. Development is moving inland, and it is becoming more expensive to discharge wastes to ocean outfalls. It has been proposed that the wastewater be treated and discharged to coastal streams for reuse in irrigation downstream during the dry season. The California Regional Water Quality Control Board projects discharges of 10 million to 30 million gallons per day of treated wastewater for 10 coastal rivers over the next 25 years (San Diego Regional Water Quality Control Board, 1988). It is uncertain how much of the flow would reach coastal wetlands, but certainly during the wet season, the wastewater discharge would exceed irrigation demands.

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Environmental Science in the Coastal Zone: Issues for Further Research It is now recognized that changing the hydrology from intermittent to continuous flows will affect coastal water bodies and endangered species habitat. The coastal wetlands are usually saline to hypersaline ecosystems. A concern that is peculiar to semi-arid regions is salinity dilution, which occurs when intermittent streams that normally provide seasonal fresh water to coastal lagoons become year-round rivers due to wastewater discharge. Some effects of dry-season flows to coastal wetlands have been documented. We know that prolonged periods of freshwater influence can force the replacement of salt marsh habitat (which is endangered species habitat) to brackish marsh (which is not) (Zedler and Beare, 1986; Beare and Zedler, 1987). Continuous freshwater flows also eliminate the marine invertebrates and shellfish that are native to many coastal lagoons. At Tijuana Estuary, the numbers of fish and macroinvertebrate species have been reduced substantially since 1986, numbers of individuals have dropped by an order of magnitude; and size distributions are markedly altered—for clams, only young-of-the-year can be found, indicating that larvae are available to settle in the estuary, but rarely survive to reproductive age (Nordby and Zedler, 1991). Experimental tests of the effect of salinity dilution on fish and invertebrates have demonstrated that low salinity causes mortality, especially of molluscs (Nordby, Zedler, and Baczkowski, unpub. data). Detailed experimentation with California halibut shows that growth of juveniles is impaired by lowered salinity and that impacts are greatest on the smallest and youngest individuals (Baczkowski, 1992). Thus, modifications to the seasonality of streamflow (i.e., the semi-arid hydrology) of the region are seen as significant impacts, beyond the more general problems of nutrients and toxic materials that are carried in wastewater. Decisionmakers are aware of the negative impacts of year-round inflows, and plans are underway to recover much of the treated effluent downstream for use in irrigation. There would still be spills and excess water during the wet season. Unfortunately, the impacts of excess freshwater discharge, of greater volumes of freshwater inflow, and of increased nutrient loadings to coastal water bodies are only generally predictable. Raw Sewage from Tijuana The city of Tijuana includes large urban areas that are not on sewer, and wastes are discharged as raw sewage to Tijuana River. About 13 million gallons per day were released to Tijuana River and Tijuana Estuary between about 1986 and 1991 (Seamans, 1988; Zedler et al., 1992). As in other regions, wastewater inflows carry unwanted materials into estuaries. What is unique in this case is the high concentration of pollutants, because of both lower per capita water use (concentrated wastewater) and fewer controls on contaminant loadings (industrial discharges). The nitrogen and phosphorus that enter the Tijuana Estuary are largely of wastewater origin. Mexican sewage contains over 25 mg/l nitrogen and greater than 10 mg/l phosphorus. We have shown that Tijuana Estuary is nitrogen limited, and that macroalgal blooms are stimulated by wastewater inflows (Fong et al., 1987). Studies of heavy metals in Tijuana Estuary showed that surface water samples contain mean levels of 69 ppb cadmium, 55 ppb chromium, 281 ppb nickel,

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Environmental Science in the Coastal Zone: Issues for Further Research and 321 ppb lead (Gersberg et al., 1989). The lead level is relatively high. The sediments of the estuary, which may act as a sink for heavy metals, contained up to 1.7 ppm cadmium, 25 ppm chromium, 14 ppm nickel, and 59 ppb lead. Hot spots of contamination do exist in the estuary. Short-term solutions and long-term plans have been developed. In fall 1991, the raw sewage was diverted to a holding lake in the United States, held briefly, and then pumped to San Diego's sewage treatment plant during off hours. However, the pumps were shut down during rain storms in winter 1992 and failed for one week in May 1992. The short-term solution is a band-aid approach. A long battle has been waged over who would pay for wastewater treatment at the border. The city of San Diego did not want to pay for treatment of "international waste". But the city did want a treatment plant that would serve new developments on the U.S. side. The federal government, in turn, did not want to pay for local infrastructures. The compromise was to build two sewage plants, a 25 millions of gallons per day plant to handle Mexico's sewage and a much larger plant to be built by the city of San Diego to treat local wastewater. To handle the effluent from both plants, a 12-foot-diameter outfall is being constructed to carry up to 300 millions of gallons per day of wastewater to the ocean. This outfall would cross Tijuana Estuary and damage a 200-foot-wide swath of endangered species habitat during construction. Mitigation is proposed. An alternative tunnel is being planned; the outfall pipe could go under Tijuana Estuary at greater construction cost. It is not clear that the estuarine biota could sustain the damages of either construction project, even with mitigation efforts. Management and Policy Needs The region faces dwindling water supplies and burgeoning effluent. The need for long-term solutions is obvious. Year-round reuse of water would obviate the need for a destructive ocean outfall. Year-round reuse would also solve problems both at the source (San Francisco bay Delta, where freshwater inflows are needed to sustain the biota of the bay) and at the disposal site. The drinking of wastewater that is produced and treated in California is permitted only if it has passed through a groundwater aquifer. The concern is apparently the potential for transmission of viruses. Further research on the safety and acceptability of total recycling is needed. Second, treated wastewater could be used to construct wetlands. Freshwater wetlands could subsidize habitat for estuarine birds; at the same time, they would improve water quality entering the estuaries. In San Diego County, freshwater bulrush (Scirpus validus) wetlands have a particularly high capability for nitrogen removal, with greater than 90 percent reduction of total nitrogen at 5-6-day hydraulic residence times (Gersberg et al., 1986). Constructed wetlands are also capable of removing both bacterial and vital indicators of pollution with a removal efficiency of nearly 99.9 percent for poliovirus (vaccine strain; Gersberg et al., 1987). Since augmented inflows are detrimental to the region's estuaries, these constructed wetlands could be engineered to discharge treated wastewater in pulses that would minimize negative impacts (i.e., salinity dilution) on the downstream estuary. Recent experimentation with pulsed-discharge regimes (alternating impoundment and discharge) demonstrated that both metal and nitrogen removal rates

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Environmental Science in the Coastal Zone: Issues for Further Research could be increased by twice-daily impoundment and discharge (Sinicrope et al., in press; Busnardo et al., in press). Several additional benefits might also occur. More nitrogen would be removed through enhanced denitrification; more metals would be immobilized through precipitation in the sediment; there might be fewer problems with mosquitoes due to the more dynamic hydrology. It appears that the problem of augmented freshwater inflows could be lessened (although not eliminated) by using pulsed-discharge wetlands to reduce the impact of salinity dilution and improve the quality of effluent entering the coastal wetlands. The potential for using constructed wetlands to manage wastewater in southern California needs to be explored. THE MITIGATION ISSUE The principal value of southern California's coastal wetlands is habitat and its role in maintaining biodiversity. Several species are dependent on our estuaries (including plants and animals, invertebrates and vertebrates, and both resident and migrant species). Three endangered bird and one plant species depend on coastal wetlands that cover less than 25 percent of their historic area and that are far from pristine. Despite laws that protect wetlands and endangered species, regulatory agencies still permit habitat alterations if mitigation plans promise compensation. Lost habitat is usually replaced by restoring disturbed wetlands, with a net loss of wetland acreage and often a decline in habitat quality (Zedler, 1991). The National Environmental Policy Act [40 CFR Part 1508.20(a-e)] defines mitigation as avoiding, minimizing, rectifying, reducing, eliminating, or compensating for impacts to natural resources. Wetland filling is regulated by the Clean Water Act, Section 404, which requires a permit for the filling of, or disposing dredge spoil into, wetlands. Filling is allowed for water-dependent uses (e.g., port facilities) and where there is ''no practicable alternative'', providing that impacts are mitigated. Wetland mitigation usually involves restoration or enhancement of disturbed wetlands. Rarely does it involve construction of new wetland habitats from nonwetlands. Whether restoration, enhancement, and construction measures can preserve coastal diversity remains a major question. Mitigation Projects in Progress The ports of Los Angeles and Long Beach propose to fill 2400-2500 acres of nearshore habitat by the year 2020 to expand port facilities. Several mitigation projects have been proposed, and at least one (at Anaheim Bay/Seal Beach National Wildlife Refuge) has been implemented. A second (374 acres of dredging at Batiquitos Lagoon) has reached the final EIR/EIS stage. Environmentalists believe the dredging is excessive and that it suits the ports' needs for mitigating fish habitat more than the lagoon's need for enhancement. The project is currently in litigation. Some projects are not water dependent, but permits are still possible in southern California. A current proposal by the city of San Diego is to relocate and expand an existing sewer pump station within an intertidal salt marsh. The specific site was recently shown to support the largest population

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Environmental Science in the Coastal Zone: Issues for Further Research of an annual plant (Lasthenia glabrata) that is considered sensitive. Mitigation would be proposed. However, the native distribution, population dynamics, habitat requirements, and reproductive characteristics of this rare plant have not been studied. Highways are usually not permitted in wetlands, but most of southern California's coastal wetlands are interrupted by three roadways (Interstate Highway 5, Pacific Coast Highway, and the Santa Fe Railroad). There are continual plans to widen these roadways, with associated impacts on the remaining wetland resources. Along San Diego Bay, the salt marsh was recently damaged by three federal projects: the widening of a freeway, a new freeway interchange, and a new flood control channel. The US Fish and Wildlife Service determined that three endangered species were jeopardized by the projects, and compensatory mitigation was required (see next section). The basic problems with mitigation in southern California are that 1) there isn't enough coastal acreage to satisfy the demand for mitigation projects; 2) too much wetland habitat has already been lost, and several species are threatened with extinction; 3) even the most disturbed wetlands provide some support for threatened species, so that changing a degraded habitat into a mitigation site causes further negative impacts; and 4) we don't understand how these degraded wetlands function. In addition to these problems, the research that has been done to assess the functional equivalency of restored and natural wetlands indicates that we do not yet know how to recreate endangered species habitats. To date, the process of mitigation has been an attempt to offset losses, but the policy breaks down at several levels, including planning, site selection, and project implementation. An Attempt to Compensate for Lost Endangered Species Habitat The San Diego Bay mitigation was a habitat conversion. Disturbed high marsh/transition was converted to low marsh for a federally endangered bird (the light-looted clapper rail). Prior to excavation, the mitigation site may have supported the Belding's Savannah sparrow, a bird on the state endangered list. No biological inventory was required or conducted to document existing values of the mitigation site. Research is continuing to assess the functional equivalency of restored and natural wetlands of San Diego Bay. In 1985, eight salt marsh islands were constructed as habitat for an endangered bird. Over a two-year period (1987-89), eleven attributes of the mitigation site were compared with those at an adjacent natural marsh. There were deficiencies in soils (Langis et al., 1991), plant growth (Zedler, in press), and marsh invertebrates (Rutherford, 1989). Sampling of soils and vegetation continued through 1992, and improvements were minimal, giving little evidence that the site will eventually support the target species, the light-looted clapper rail. Compared with reference marshes, the sediment was sandier and had little organic matter. With less soil organic matter, there was less energy and nitrogen for microbial mineralization and less energy for nitrogen fixation. With lower nitrogen inputs, plant growth was limited and foliar nitrogen was lower. With lower plant production and lower-quality plant biomass, the detrital food chain was probably impaired, as indicated by lower abundances of invertebrates in the epibenthos. Five years after construction, the best sites (areas with highest plant cover) provided less than 60 percent of the

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Environmental Science in the Coastal Zone: Issues for Further Research functional value of the natural reference wetland (Zedler and Langis, 1991). More recent research shows that canopy architecture (cordgrass height and density) differed for the planted marshes (which do not support clapper rails) and natural marshes. Tall plants are needed to support nesting and provide protection from aerial predators. Transplanted marshes have few plants over 60 cm, while most stems in natural marshes exceed 60 cm (Zedler, in press). This appears to be a major reason why the marsh islands are not yet used by the light-looted clapper rail. It should be possible to accelerate development of these ecosystem processes using scientific knowledge and experimentation at existing mitigation projects. Current policies are not sufficient to protect against extinction. Research is underway to find soil amendments and enrichment schedules that will produce taller, denser cordgrass in a shorter period of time. Preliminary experiments with straw, alfalfa, and inorganic nitrogen fertilizers show that nitrogen addition can improve plant growth (Gibson, 1992). However, after 2 years, the canopy architecture is not yet equivalent to that of natural marshes. Continued research and repeated applications seem to be necessary. Management Policies and Issues It has not yet been shown that damages to endangered species habitat can be reversed or that lost wetland values can be replaced. Replacement of functional values is slow and incomplete. Yet, policies have not been changed to reflect the inadequacy of mitigation projects. Permits are still being granted with the promise that habitat can be replaced. Several federal policies are not appropriate for the southern California situation. Mitigation priorities: Federal mitigation policy (Environmental Protection Agency and Corps of Engineers Memorandum of Agreement) recommends that restoration be given priority over the creation of new wetlands from upland. This policy makes sense in some places, such as prairie potholes that are drained and farmed and no longer function as wetlands. Restoration of former potholes is more likely to provide the correct hydrology than excavation of potholes from natural upland. However, where damaged wetlands still perform critical functions, as in southern California, this strategy is doubly damaging-first, the restoration site is altered without knowing what existing values were lost; second, there is a net loss in wetland area. Mitigation ratios and "net loss of acreage and function: "The recommendation that mitigators restore 2-4 times the area they damage is a good idea. However, it is not sufficient where endangered species habitats are concerned. Since even the disturbed wetlands have valued functions, the use of a 2:1 mitigation ratio (i.e., restoration of 2 acres of marsh for every 1 acre lost) does not fulfill the policy of no net loss of wetland area. Instead, there is a net loss of 1 acre of wetland area. Only the creation of wetland from non-wetland areas can replace lost wetland acreage. Lower functional value of restored or created wetlands does not compensate for lost endangered species habitat. Even if 3:1 or 4:1 compensation is required, a larger area of unusable habitat will not replace the functional value of one acre that is critical to the endangered population. At the very least, agencies should require assessment of the functioning of the mitigation site prior to and after improvements, plus up-front mitigation, with success achieved and documented prior to destruction of the development site.

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Environmental Science in the Coastal Zone: Issues for Further Research Sediment removal: Most restoration projects in southern California involve excavation of sediments that have accumulated from coastal watersheds or former fills. However, sediments may ultimately be needed to offset sea-level rise. Most agencies lack policies that require consideration of accelerated rates of sea-level rise in their long-term planning. Dredge spoil disposal: Off-site disposal of fine sediments is extremely costly and may be environmentally damaging to the disposal site. A proposed solution for disposal of fine sediments at Batiquitos Lagoon is to bury them in situ, first excavating the underlying sand and using it for beach replenishment. However, this would extend the time period of the disruption of biota of Batiquitos Lagoon, and temporary stockpiles of spoils would affect nearby coastal areas. Regional plans for sediment disposal are needed, with an emphasis on finding beneficial uses of the material (e.g., capping toxic waste deposits). Research policies: The National Oceanic and Atmospheric Administration’s Coastal Ocean Program proposes to develop a conceptual model of estuarine habitat function based on East Coast models (Costanza et al., 1990). The objective is to "relate the location and extent of seagrass and salt marsh habitats to the production of living marine resources in an estuary or region" (Sutherland, 1991). Although this program has provided some support for the soil amendment experiment in San Diego Bay, most of the funding has been for research in East Coast and Gulf Coast habitats. The applicability of production models to southern California management issues concerning endangered species habitats is questionable. Research funding agencies need to recognize the unique attributes of Pacific Coast ecosystems and to reevaluate the geographic distribution of their funding efforts. THE STATUS OF RESEARCH ON COASTAL SOTHERN CALIFORNIA ECOSYSTEMS In November 1991, the California state Sea Program sponsored a work on "Research Needs for Restoring Sustainable Coastal Ecosystems on the Pacific Coast" at the Estuarine Research Federation meetings in San Francisco (Williams and Zedler, 1992). The consensus was that ecosystems research on Pacificestuaries lags behind that on Atlantic and Gulf Coast estuaries by several decades. Even basic data on California estuarine wetlands (size, type, historic condition) are unavailable. Little is known of the habitat requirements of Pacific estuarine species, including plants, fish, and wildlife. For plant species that have been studied, suchas Salicornia virginica and Spartina foliosa, we still do not have data on below ground dynamics. For these and other unstudied species, we lack data on dispersal mechanisms, reproductive strategies, and genetic structure. Esturine food webs have not been elucidated, and feeding relations have not been quantified. The research needs are numerous, as indicated by attendees at the recent national workshop (Table 2).

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Environmental Science in the Coastal Zone: Issues for Further Research CONCLUSION The uniqueness of Pacific coastal wetlands requires a regional approach to research and management. Whereas the nutrient content of fresh water entering East Coast and Gulf Coast estuaries needs to be controlled, in southern California the amount and timing of discharges must also be managed in order to maintain native vegetation and associated fauna. It is not sufficient for managers to worry only about the loss of fish and shellfish habitat, because endangered species are often jeopardized by wetland loss in southern California. Management models cannot be derived by extrapolation from data of East Coast and Gulf Coast estuaries, where inflows are more predictable and where plants and animals are more tolerant of brackish water. REFERENCES Baczkowski, S. 1992. The effects of decreased salinity on juvenile California halibut, Paralichthys californicus. M. S. Thesis, San Diego State University. Beare, P. A., and J. B. Zedler. 1987. Cattail invasion and persistence in a coastal salt marsh: The role of salinity. Estuaries 10:165-170. Busnardo, M. J., R. M. Gersberg, R. Langis, T. L. Sinicrope, and J. B. Zedler. In press. Nitrogen and phosphorus removal by wetland mesocosms subjected to different hydroperiods. Ecological Engineering. Costanza, R., F. H. Sklar, and M. L. White. 1990. Modeling coastal landscape dynamics. Bioscience 40:911 07. Dahl, T. E. 1990. Wetlands losses in the United States, 1780's to 1980's. Washington, D.C.: U.S. Department of the Interior, Fish and Wildlife Service. Department of Fish and Game. 1989. 1988 Annual Report on the Status of California's State Listed Threatened and Endangered Plants and Animals. Sacramento, California: Resources Agency. Fong, P., R. Rudnicki, and J. B. Zedler. 1987. Algal Community Response to Nitrogen and Phosphorus Loadings in Experimental Mesocosms: Management Recommendations for Southern California Coastal Lagoons. Technical Report to SANDAG, San Diego, California. Gersberg, R. M., B. V. Elkins, S. R. Lynn, and C. R. Goldman. 1986. Role of aquatic plants in wastewater treatment by artificial wetlands. Water Resources 20:363-368. Gersberg, R. M., S. R. Lynn, R. Brenner, and B. V. Elkins. 1987. Fate of viruses in artificial wetlands. Applied Environmental Microbiology 53:731-736. Gersberg, R. M., F. Trindade, and C. S. Nordby. 1989. Heavy metals in sediments and fish of the Tijuana Estuary. Border Health V:5-15. Gibson, K. 1992. The effects of soil amendments on the growth of an intertidal halophyte, Spartina foliosa. M. S. Thesis, San Diego State University. Langis, R., M. Zalejko, and J. B. Zedler. 1991. Nitrogen assessments in a constructed and a natural salt marsh of San Diego Bay, California. Ecological Applications 1:40-51.

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Environmental Science in the Coastal Zone: Issues for Further Research Nordby, C. S. and J. B. Zedler. 1991. Responses of fishes and benthos to hydrologic disturbances in Tijuana Estuary and Los Peñasquitos Lagoon, California. Estuaries 14:80-93. Onuf, C. P. and M. L., Quammen. 1983. Fishes in a California coastal lagoon: Effects of major storms on distribution and abundance. Marine Ecology 12:1-14. Rutherford, S. E. 1989. Detritus production and epibenthic communities of natural versus constructed salt marshes. M. S. Thesis, San Diego State University. San Diego Regional Water Quality Control Board. 1988. Staff report on stream enhancement and reclamation potential 1988 through 2015. San Diego. 35 pp. San Diego Region Water Quality Control Board. 1988. Staff Report on Stream Enhancement and Reclamation Potential 1988 through 2015. San Diego, California. San Diego Unified Port District. 1990. South San Diego Bay Enhancement Plan, Vol. 1, Resources Atlas. Oakland, California: California State Coastal Conservancy. Seamans, P. 1988. Wastewater creates a border problem. Journal of the Water Pollution Control Federation 60:1798-1804. Sinicrope, T. L., R. Langis, R. M. Gersberg, M. J. Busnardo, and J. B. Zedler. In press. Metal removal by wetland mesocosms subjected to different hydroperiods. Ecological Engineering. Sutherland, J. 1991. NOAA Coastal Ocean Program Estuarine Habitat Program. Proceedings of a Workshop of Principal Investigators, Horn Point, Maryland. November 1991 Draft. Silver Spring, Maryland: National Oceanic and Atmospheric Administration. Williams, P. B. and M. L. Swanson. 1987. Tijuana Estuary Enhancement: Hydrologic Analysis. Oakland California: California State Coastal Conservancy. Williams, S. L. and J. B. Zedler. 1992. Research Needs for Restoring Sustainable Coastal Ecosystems on the Pacific Coast. LaJolla, California: California Sea Grant College. Zedler, J. B. 1991. The challenge of protecting endangered species habitat along the southern California coast. Coastal Management 19:35-53. Zedler, J. B. In press. Canopy architecture of natural and planted cordgrass marshes: Selecting habitat evaluation criteria. Ecological Applications. Zedler, J. B. and P. A. Beare. 1986. Temporal variability of salt marsh vegetation: the role of low-salinity gaps and environmental stress. Pp. 295-306 in D. Wolfe, ed., Estuarine variability. New York, New York: Academic Press. Zedler, J. B. and R. Langis. 1991. Comparisons of constructed and natural salt marshes of San Diego Bay. Restoration & Management Notes 9(1):21-25. Zedler, J., C. Nordby, and B. Kus. 1992. The ecology of Tijuana Estuary: A national estuarine research reserve. Washington, D.C.: National Oceanic and Atmospheric Administration Office of Coastal Resource Management, Sanctuaries and Reserves Division.

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Environmental Science in the Coastal Zone: Issues for Further Research Attachment 8.1 Major Uses of the Southern California Coast Ports: The ports of Los Angeles and Long Beach occupy San Pedro Bay. To expand their role as the major Pacific Rim shipping center, they propose to fill 2400 more acres of shallow subtidal habitat by the year 2020. Problems: Nearshore fish habitat will be filled. Mitigation to compensate for lost habitat is mandated, but there are no nearby sites where compensatory habitat restoration or construction can occur, because all the historic sites have been filled and urbanized. Marinas: Many former wetlands have marinas. There is constant pressure to increase the number of boat slips for San Diego's growing population and its substantial tourism industry. America's Cup generated further expansion. Problem: Marina development impacts eelgrass beds and associated fisheries (e.g., California halibut). No studies have documented the functional value of natural eelgrass beds or of mitigation sites where eelgrass has been transplanted. Since so much eelgrass habitat has been destroyed, and since eelgrass is a clonal species, transplanted eelgrass beds may lack genetic diversity. Urbanization: Most of the coast above mean high water is urbanized. Were it not for a military base (Camp Pendleton), the 120-mile coast between Los Angeles and San Diego would be one continuous urban strip. The San Diego region now has 2.5 million people, with approximately 2 million more in adjacent Tijuana, Baja California. The growth rate is variable for the San Diego area, but newcomers averaged 85,000 per year from 1987-89. Problems: There is no buffer zone between urban areas and coastal habitats. Urban runoff degrades coastal water bodies; noise, lights, and human activities occur immediately adjacent to endangered species habitats. There is constant pressure to use wildlife preserves. Military bases: San Diego grew up around the Naval Base on San Diego Bay. There is also a Marine Corps Recruit Training Depot on San Diego Bay and a Marine Base (Camp Pendleton) in northern San Diego County. There are military airfields at Tijuana Estuary (helicopters) and Miramar Naval Airfield (jets), which is just north of San Diego. Problem: It is not known whether coastal military bases are releasing contaminants. Contaminants from anti-fouling paints (e.g., tributyltin, copper) are known to be a problem at the Navy harbor. Problem: San Diego Bay must be dredged to maintain ship channels.

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Environmental Science in the Coastal Zone: Issues for Further Research Problem: Helicopters practice about 950 takeoffs and landings per day, with flights directly over the Tijuana River National Estuarine Research Reserve. Airports: Tijuana, San Diego, Long Beach, Los Angeles, and Santa Barbara all have commercial airports. San Diego's airport is entirely surrounded by high-cost housing, commercial, and military land uses. Various alternatives are under consideration for major expansion. Problem: Expansion in situ would encroach on the Marine Corps Recruit Depot and increase noise levels for nearby residents. Relocation to Miramar Naval Airfield would interfere with military activities. Locating a new airport adjacent to the international border (adjacent to Tijuana's airport) would increase flights over Tijuana and have planes taking off and landing over a National Estuarine Research Reserve. All U.S. users of the airport live north of the latter site; travel to and from the airport would be maximized, with most people having to drive through San Diego to reach the airport. Agriculture: Minimal agricultural efforts are carried out along the coast; however, there are agricultural activities in the Tijuana River Valley, several areas of floriculture inland of coastal lagoons, and vegetable farming on the marine terrace at Camp Pendleton. Problem: Non-point source pollutants and irrigation runoff flow into coastal wetlands. Algal blooms and fish kills are possible impacts. Recreation: Sandy beaches offer many recreational opportunities. Mission Bay Park is billed as the "world's largest urban water-recreation park" (1,888 acres). Formerly shallow subtidal and wetland habitat, the park was constructed by dredging embayments and building islands. The area now supports waterskiing, jet skiing, sailing, rowing, canoeing, kayaking, swimming, sunbathing, and passive nature appreciation. At Tijuana Estuary, horse trails are heavily used by equestrian clubs and rental operations. Problems: Incompatible uses are crowded into small areas. Noisy boats and jet skiers have negative impacts on those seeking quiet. Accidents occur in Mission Bay, jet skiers and boaters collide; at Tijuana Estuary, hikers get kicked by horses. It is not easy to eliminate incompatible users. A model airplane club that was located within the Tijuana River National Estuarine Research Reserve was ruled as incompatible when planes repeatedly crashed at an experimental research site. But it took over five years and considerable expense to evict them, even though their lease had expired. Research and Education: These activities take place at several habitat remnants along the coast. Visitor centers occur at Tijuana Estuary, San Diego Bay, and at some of the north county lagoons. Tijuana Estuary is a research reserve, but it is managed by the California Department of Parks and Recreation, which does not have a research mandate.

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Environmental Science in the Coastal Zone: Issues for Further Research Problem: Intensive use is damaging to native habitats and species; yet trails are desired for interpretive purposes. Most habitats are used by sensitive species, so there is no good place for interpretive or recreational facilities. Blinds are often suggested, but homeless people and undocumented migrants on their way north are attracted to such structures. International Border: Every day, hundreds of undocumented immigrants cross the border at Tijuana, Mexico. The traffic flows on many undesignated paths, a number of which cross through or near endangered species habitat, such as the beach areas where California least terns nest. Problems: Many of the immigrants walk, wade, and swim through Tijuana Estuary. They damage the habitat, as does the Border Patrol force, whose job it is to pursue and arrest them. Nests of endangered birds are damaged. Gravel and sand extraction: Coastal rivers have been mined for both sand and gravel. These materials are highly valued in a region undergoing rapid development. An extraction company has developed an ambitious proposal to remove the surface 180 feet of the highlands [at the U.S.-Mexico border, sell the sand, and crush the cobbles to make gravel]. Problem: These highlands are an important buffer between Tijuana River Valley and the metropolis along the Mexico border. Eliminating these bluffs would have serious impacts on the integrity of the national estuarine research reserve. The long-term extraction period (> 10 years) would disrupt endangered species habitat throughout the valley. It is estimated that there would be more than one truck per minute transporting sand or gravel, plus the construction and operation of a rock crusher. Coastal reserves: Coastal wetlands makeup a small but important acreage along the coast, since they support many species that are threatened with extinction. Several sites have been set aside for various conservation purposes. Tijuana Estuary is a national estuarine research reserve; it includes a state park and a national wildlife refuge for endangered species. At San Diego Bay, the Sweetwater Marsh is a national wildlife refuge. At Mission Bay, the Kendall-Frost Reserve is owned by the University of California and is set aside for research. North of San Diego, there are several coastal lagoons that are ecological reserves. The California Department of Parks and Recreation owns Los Peñasquitos Lagoon; the county of San Diego owns San Elijo Lagoon; and the California Department of Fish and Game owns Buena Vista Lagoon. Private holdings include large parts of Agua Hedionda Lagoon (San Diego Gas & Electric) and Ballona Wetland near the Los Angeles Airport (250 acres, Maguire Thomas Partners). Problem: No single agency manages the region's wetlands. Yet migratory birds and mobile fishes and invertebrates are often the management target. Several species that are unique to the region are threatened with extinction. Tijuana Estuary supports 24 sensitive plant and animal species, yet the management of these populations is not easily coordinated within the region.

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Environmental Science in the Coastal Zone: Issues for Further Research Problem: California's 91 percent loss of historic wetland area indicates that further extinctions will occur. E. 0. Wilson's island biogeography model predicts that 50 percent of the species will be lost when 90 percent of the habitat is eliminated. Problem: It is extremely costly to purchase wetland remnants for the public. The Famosa Slough was recently purchased by the city of San Diego (20 acres for $3.5 million) for a nature reserve and for public interpretation. This site had a development plan but it would probably not have received a Section 404 permit. Near Santa Barbara, public agencies paid over $340,000 per acre to acquire a 4-acre parcel adjacent to Carpinteria Marsh for purposes of restoration. This filled site was developable land. Problem: Proposed changes in the wetland delineation guidelines would seriously impair habitat conservation efforts. The higher elevations of coastal marshes support rare and endangered plants (the salt marsh bird's beak) and insects (mudflat tiger beetles). With increased rates of sea-level rise, the upper marsh and transition habitats must be available for the landward migration. The Environmental Protection Agency calculates that a half meter rise by the year 2100 is probable—this would eliminate 65 percent (6441 square miles) of the wetlands of the contiguous United States. Problem: Restoration plans are designed to meet the needs of mitigators, rather than what may be most functional at the site or most needed in the region. No program has been developed to assess the quality of each habitat type in the region, to assess losses by habitat type, or to determine the habitat needs of the region. Almost all mitigation planning is done on a piecemeal basis. Problem: Much of the wetland area that remains in the region is publicly owned, but no single agency owns all the reserves. Management is accomplished on a site-by-site basis.

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Environmental Science in the Coastal Zone: Issues for Further Research Attachment 8.2 Research Priorities for Sustainable Pacific Estuaries This list is divided into four subject areas of equal importance: conservation of biodiversity, physical processes, water quality, and restoration. The categories were numerically ranked by workshop participants using 1 as the highest and 3 as the lowest priority. The tally below represents the mean ranking by fifteen respondents. Conservation of Biodiversity Research Needs Mean Rank Value Categories 1.27 Habitat function determinants   structural (marsh edge, canopy height)   functional (productivity, trophic support) 1.30 Habitat requirements/habitat specificity of organisms   primary determinants of habitat utilization (trophic/reproduction requirements)   structure (e.g., habitat heterogeneity, canopy height)   function (e.g., productivity) 1.42 Population dynamics   genetic structure and diversity   minimum viable population sizes   community development processes (rates, rate-limiting processes)   below ground vegetation processes 1.89 Linkages between communities and habitats 1.90 Trophic dynamics   food web analysis   emergent insect communities 2.02 Exotic species biology   dispersal mechanisms   competitive effects   trophic effects 2.09 Habitat inventory   determination of estuarine acreage and habitat types   community profiles on sites with long-term data base

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Environmental Science in the Coastal Zone: Issues for Further Research Mean Rank Value Categories 2.10 Endangered species biology 2.65 Effects of rare events Physical Processes Research Needs 1.23 Hydrology   effects of altered hydrology   effects of vegetation   effects of marsh morphology (channel vs. overmarsh flow)   effects of alternating wet-dry cycles   models 1.78 Erosion/accretion responses   role of organic vs. inorganic matter in accretion   integration with hydrological effects   sediment supply processes 1.97 Model of salinity dynamics (modal & extreme) 2.22 Effects of anticipated sea level rise 2.36 Marsh morphology   role of extreme events   comparisons between marsh types Water Quality Research Needs 1.51 Nutrient dynamics   process rates   budgets   organic matter accumulation and decomposition rates   effects of alternating wet-dry cycles   effects of altered hydrology 1.53 Criteria for vegetation 1.71 Urban runoff

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Environmental Science in the Coastal Zone: Issues for Further Research Mean Rank Value Categories 1.81 Impacts of development 1.90 reatment strategies Restoration Research Needs 1.17 Inventory of projects and monitoring 1.29 Habitat architecture   habitat size to sustain minimum viable population sizes and functionality   habitat heterogeneity   landscape linkages and corridors   buffer zone requirements 1.59 Site selection criteria   identification of potential sites   consideration of regional habitat biodiversity   urban problems 1.65 Monitoring and evaluation of success   assessment and standardization of functionality evaluation criteria   assessment of appropriate temporal scales of monitoring   assessment criteria for urban projects where no natural sites remain for comparison   assessment of structure (e.g., canopy height) as surrogates for function 1.94 Methodology   identification of desired initial conditions   establishment of desired initial conditions   independent tests of design strategies   acceleration of functional development trajectory   incorporation of effects of rare/stochastic events in design 2.48 Economic evaluation of adequacy of mitigation/restoration options as compensation for loss   Source: Williams and Zedler, 1992.