General Description Wetlands are broadly dened as the transitional lands that occur between the terrestrial and aquatic systems where the water table is usually at or near the surface, or the land is covered by shallow water. There are ve major systems of wetlands — marine, estuarine, riverine, lacustrine (lake), and palustrine (freshwater marsh). This paper discusses California’s marine and estuarine wetland systems. However, it should be noted that all ve systems occur in the state, all of which serve important roles as sh and wildlife habitat and in many ways are ecologically tied to one another. One of the most widely used and comprehensive wetland classication system was developed for the U.S. Fish and Wildlife Service and is referred to as the Cowardin denition. This classication system denes wetlands as having one or more of the following three attributes: 1) at least periodically, the land supports predominantly hydrophytes; 2) the substrate is predominantly undrained hydric soil; and 3) the substrate is nonsoil and is saturated with water or covered by shallow water at some time during the growing season of each year. Although this system is commonly used to classify wetlands, regulatory agencies such as the U.S. Army Corps of Engineers, the U.S. Environmental Protection Agency, and other public agencies use varying denition when regulating the discharge of dredged or ll material or other alterations to wetland areas. The term “tidal wetland” refers to areas that are covered with shallow intermittent tidal waters. Coastal tidal wetlands in the California include a number of natural communities that share the unique combination of aquatic, semi-aquatic, and terrestrial habitats that result from periodic ooding by tidal waters, rainfall, and runoff. These coastal wetlands, also referred to as salt marshes, provide a vital link between land and open sea, exporting nutrients and organic material to ocean waters. Wetlands also help to improve water quality, protect lands from ooding, provide energy to the estuarine and marine food webs, and help stabilize shorelines against erosion. Tidal wetlands are dominated by a community of plants that are tolerant of wet, saline soils, and are generally found in low-lying coastal habitats which are periodically wet and usually saline to hypersaline. In fact, no other feature denes a salt marsh better than the plant communities that form there. The location of plant species within a salt marsh is dened by zone, with cordgrass (Spartina foliosa) forming the most seaward edge of the emergent marsh plant community. Of the thousands of plant species in North America, only cordgrass thrives in

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the lowest zone of a salt marsh. This lower marsh zone occurs from approximately mean sea level to the line of mean high tide. The middle zone of a tidal marsh occurs from approximately the line of mean high tide to the mean higher high tide line and is characterized by the occurrence of pickleweed (Salcornia sp.). Pickleweed is less tolerant of tidal inundation than cordgrass, but is the most dominant plant of California tidal wetlands. Jaumea (Jaumea carnosa) also occurs, but to a lesser extent within the middle zone of California’s coastal marshes. The upper zone of a tidal marsh is dened by the line of mean higher high tide to extreme high tide. This upper zone of a salt marsh may only be inundated infrequently, in some locations as little as once or twice annually. Such innundation usually occurs during the spring tide cycle (highest annual tides) and during severe storm events. The upper zone of the tidal marsh is characterized by the dominance of salt grass (Distichlis spicata) which tolerates only occasional tidal inundation. This upper area of marshes contains the largest plant species diversity of the three zones. Species such as fat hen (Atriplex patula), sand spurrey (Spergularia marina), marsh rosemary (Limonium californicum), brass buttons (Cotula cornopifolia), can be found within the upper zone of salt marshes throughout California. In the southern portion of the state, species such as Australian salt bush (Atriplex semibaccata), sea-bite (Suaeda californica and Suaeda fruticosa), shoregrass (Monanthochloe littoralis), and salt marsh bird’s beak (Cordylanthus sp.) can be found within the upper salt marsh zone.

Coastal Wetlands - Emergent Marshes

Coastal Wetlands Emergent Marshes

The zonation of marshes in southern California is somewhat more complex than that described above. Southern California salt marshes lack expansive stands of cordgrass; instead they are dominated by succulents. Within the Mugu Lagoon, Anaheim Bay, Newport Bay, Mission Bay, San Diego Bay, and the Tijuna River estuary, zones of saltwort (Batis maritima) and annual pickleweed (Salcor-

Carpinteria Salt Marsh, Santa Barbara Co. Credit: USEPA, 1995

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nia bigelovii) integrate with cordgrass in the lower zone and perennial pickleweed (Salcornia virginica) and other middle zone plant species occur at higher than normal elevations in these and other southern California marshes. In addition to the plant communities, other dening characteristics often associated with California’s tidal wetlands include mudats, tidal creeks, intertidal channels and sloughs, salt ats, and shallow pannes. Fresh water inows are also often found in many of the state’s coastal wetland areas, adding to the diversity of habitat types and associated species use. Many of California’s coastal wetlands are estuarine salt marshes. These salt marshes, associated mudats, and eelgrass beds develop along the shores of protected estuarine bays and river mouths, as well as in more marinedominated bays and lagoons. Overall, the state’s tidal and estuarine wetland ecosystems provide some form of food, shelter, or other benets to nearly a thousand species of sh, amphibians, reptiles, birds, mammals, and a multitude of invertebrates. During peak annual migration periods, hundreds of thousands of birds migrating along the Pacic Flyway descend upon the state’s estuarine wetlands in search of refuge and food. California’s tidal wetlands also provide habitat for an array of endangered species, including the salt marsh harvest mouse, California clapper rail, certain runs of salmon, and wetlands plants such as a species of salt marsh birds peak. Wetlands produce an abundant yield of vegetation, which in turn provides the basis for a complex food chain nourishing a rich assortment of living organisms. The diversity and abundance of organisms in coastal wetlands is remarkable, given the often extreme and variable conditions that can occur. Bacteria, protozoa, algae, vascular plants, invertebrates, amphibians, sh, birds, and mammals can all be found within the state’s coastal wetland ecosystems, and together comprise the biotic community of the wetland. Many of these organisms are dependent on the wetland for their existence, either spending their entire lives in the wetland, or spending a critical portion of their life cycle in the wetland.

Status of Biological Knowledge Literature on wetland science addresses a broad range of topic and setting, and much has also been written specic to California’s estuarine and coastal wetlands. Programs such as the San Francisco Bay National Estuary Project, San Francisco Bay Baylands Ecosystem Habitat Goals Project, and organizations such as the Pacic Estuarine Research Laboratory, state and private universities, and numerous state and federal resource agencies have contributed extensively to the knowledge base of California’s coastal wetland ecosystems. This is not to say that questions do not remain about the functions and science of the state’s coastal wetlands. Scientic study in the eld of wetland science is ongoing. The role that the state’s coastal wetland habitats play in the support of sh and wildlife resources is an area of extensive research, particularly in the effects of, and techniques for enhancement and restoration. Many of the coastal wetland restoration projects undertaken within the state include research and monitoring aspects within the project designs. Such analyses are vital to the overall knowledge base of wetland science and are critical to the improvement of subsequent wetland restoration activities.

Status of the Habitat Human inuence along California’s coastline has a long history. The effect of this history is evidenced by the profound alteration of the natural environment, most pronounced of which are the modication of the shallowwater habitats within the state’s bays and estuaries and the staggering loss of coastal wetlands. The total loss of California coastal wetlands is estimated at ve million acres. This represents some 91 percent of the historic wetland acreage present before 1850. Although the entire coastline of the state has experienced losses of coastal wetland habitat, the largest losses are believed to have occurred in the San Francisco Bay estuary and along the southern coast of the state.

A variety of activities have contributed to the dramatic loss of California’s wetlands. These include diking, lling, Estimated Estimated Estimated draining, and vegetation removal for agricultural uses; Percent Remaining Original diking and lling for residential, commercial, and indusReduction Acreage Acreage Region trial development; placement of ll material for road and Northern Coast unknown 31,300 unknown pad construction associated with oil and gas exploration Central Coast unknown 3,800 unknown and development; lling and other associated construction San Francisco Bay 93,000 54% (tidal and mudflat) 200,000 for roads, highways, and railways; dredging and lling Southern Coast 53,000 13,100 75% for port and marina development; and channelization and Statewide 5,000,000 450,000 91% lling for ood control purposes. Coastal wetland losses, including those historically occurring within bays and estuHistoric Losses of California Coastal Wetlands Historic Losses of California Coastal Wetlands aries, throughout the state are primarily attributed to Source: Procedural Guidance for the Review of Wetland Projects in California’s urban development. Although state and federal regulaSource: Procedural Guidance for the Review of Wetland Projects in California’s Coastal Coastal Zone, California Coastal Commision. Zone, California Coastal Commission.

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Coastal Wetlands - Emergent Marshes Principle Coastal Wetlands of California

tions, as well as social pressures have reduced activities that cause wetland losses, many are still occurring. Much of the current loss of wetlands is attributed to a lingering legacy of past development, such as continued use of wetland areas for agriculture, or expansion of existing urban and industrial complexes within wetland habitats. Secondary or indirect impacts also have contributed to the continued loss of coastal wetlands, including point and non-point source storm and wastewater discharges, and

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alteration of natural fresh and salt water inows to the state’s estuaries and wetland areas. The Bolsa Chica wetlands in the Huntington Beach community is a site of recent controversy over wetland development and is an example of one of southern California’s continuing struggles with the preservation of remnant coastal wetlands. The Bolsa Chica wetlands are the largest stretch of unprotected coastal marshland south of San Francisco, and provide 1,100 acres of wetland habitat, sup-

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porting many species of plants, sh, and wildlife, including several endangered species of birds, such as the California least tern, light-footed clapper rail, Belding’s Savannah sparrow, and peregrine falcon. Southern California once had over 53,000 acres of coastal wetland areas. This number is now down to approximately 13,000 acres. Such wetland losses have contributed to a decline in California’s wintering bird population. Once estimated to be about 60 million, yway populations now uctuates between two and four million waterfowl, one and two million shorebirds. For the Pacic Flyway as a whole, there has been some improvement in recent years, partly because of the end of a multi-year drought in the northern breading areas, but also because of the efforts made at restoring California’s coastal and inland wetlands. In many ways, the degree and type of tidal wetland habitat losses within the San Francisco Bay estuary reect what has occurred in the state. Early reclamation activities resulted in the draining and diking of tidal, freshwater, and brackish marshes in the San Francisco Delta, as well as around Suisun Bay and San Pablo Bay. Much of this reclaimed land was cultivated for agricultural purposes. Additionally, the construction of salt production facilities resulted in the conversion of thousands of acres of tidal marsh to permanent salt pond operations. At the end of World War II, urbanization of the San Francisco Bay Area resulted in the conversion of intertidal and subtidal habitats to urbanized uplands. As a result of these wetland conversion activities, it is estimated that 95 percent of the estuary’s tidal marshes have been leveed or lled. Some of the converted wetland areas, such as salt ponds and diked lowlands, remain as wetland habitat, but of a different type, offering substantially altered functions than that which existed before conversion. At present, it is estimated that less than 38,000 acres of tidal wetlands remain in the San Francisco Bay estuary, with an additional mudat habitat of approximately 65,000 acres, diked seasonal wetland habitat of approximately 58,000 acres, and salt ponds and salt crystallization facilities of approximately 36,500 acres of non-tidal wetland habitat. Losses and alteration impacts of tidal wetland habitat associated with coastal inlets and riverine estuaries along the California coast have also been great. Many of the state’s historical wetland areas of this type have been lost or reduced in size due to direct impacts such as channelization, dredging and continued breaching of outer sandbars for ood control, and marina and harbor construction. However, off-site activities including water diversion and sediment inputs associated with watershed alterations including logging and agricultural cultivation also have signicantly impacted California’s coastal tidal wetlands. California’s remaining coastal wetlands are highly valued as habitat for the multitude of species that depend on

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them, and as aesthetic, functional, environmentally necessary elements. In fact, tidal wetland protection and restoration activities have become front-page news in many areas of the state and funding sources, once unobtainable, are now becoming increasingly available. Even with such changes in the political, economical, and environmental settings, much work needs to be done to recapture and protect California’s tidal wetland habitats. Additional research and continued monitoring of existing wetland restoration projects are needed to build and contribute to the database on how best to address and undertake these activities. Additionally, methods need to be developed to address problems which could lead to the further loss of coastal wetland areas due to the anticipated rising sealevel, and other factors such as invasive species. Further public education, community involvement, and political action are needed. Eric J. Larson California Department of Fish and Game

References California Coastal Commission. 1987. California coastal resources guide. 384 pp. Faber, P.M. 1990. Common wetland plants of California: a eld guide for the layman. Pickleweed Press. 110 pp. Goals Project. 1999. Baylands ecosystem habitat goals. A report of habitat recommendations prepared by the San Francisco Bay Area Wetlands Ecosystem Goals Project. U.S. Environmental Protection Agency, San Francisco, CA. and San Francisco Bay Regional Water Quality Control Board, Oakland, CA. Josselyn, M. 1983. The ecology of San Francisco Bay tidal marshes: a community prole. U.S. Fish and Wildlife Service, Biological Services Program. Washington D.C. FWS/ OBS-82/23. Josselyn, M., L. Handley, M. Quammen, and D. Peters. 1994. The distribution of wetlands and deepwater habitat in San Francisco Bay Region. NWRC Open File 94-04. U.S. Department of Interior National Biological Survey, Washington D.C. Resources Agency of California. 1997. California’s ocean resources: an agenda for the future. State of California, Resources Agency, Sacramento. Zedler, J.B. 1982. The ecology of southern California coastal salt marshes: a community prole. U.S. Fish and Wildlife Service, Biological Services Program. Washington D.C. FWS/OBS-81/54.

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Eelgrass Introduction Worldwide there are more than 50 species of vascular plants capable of inhabiting the shallow saline waters of the estuarine environment. The most common of these species, occurring in full-strength seawater, are the seagrasses. One of the most studied seagrasses in temperate and tropical regions is eelgrass (Zostera spp.). The eelgrass commonly found in North America, Z. marina, is widely distributed in the temperate zones of both coasts. Along the U.S. Pacic Coast, Z. marina occurs from Alaska to Baja California. Another species, Z. asiatica, is also found in a number of locations on the west coast of North America including offshore of the Santa Barbara area in California at depths up to 45 feet. Eelgrass beds are generally regarded as highly productive habitats that support a rich assemblage of sh species and provide a refuge area for larval and juvenile shes. Eelgrass habitat is also a very important resource for a variety of birds. It is associated with rich bottom fauna important to waterbirds, especially diving birds and mollusc-eaters. In California’s bays and estuaries north of Monterey Bay, eelgrass provides spawning habitat for Pacic herring. Large numbers of waterbirds such as scoters, bufehead, scaup, goldeneyes, American coots, eat eggs deposited onto eelgrass by Pacic herring during the mid-winter spawn. In addition, many birds such as surface-feeding ducks and other waterfowl, including the black brant, feed directly on eelgrass.

nutrients. Organic material from natural decomposition processes or human inuences are ltered and collected by eelgrass leaves and turions, providing a nutrient source for the eelgrass bed community. Nutrients that otherwise would accumulate in the sediments or be ushed out to sea may thereby be retained and recycled within the estuarine ecosystem. The decline in eelgrass communities during the 1930s and 1940s encouraged the initiation of studies to gain a better understanding of this vital estuarine habitat. In recent years, the importance of eelgrass communities has resurfaced as a signicant measure of the health of bays and estuaries. Some protection of this ecosystem has been afforded over the years through management practices that protect it through disturbance avoidance or in-kind replacement mitigation. In southern California further protection as also been provided by the implementation of the multi-agency Southern California Eelgrass Mitigation Policy of 1991 which is routinely included within permit conditions of both the U.S. Army Corps of Engineers and California Coastal Commission. While this policy was specically designed to address eelgrass impacting projects in southern California, its principals have, at times, also been applied permit conditions for projects occurring in

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The location, abundance and health of eelgrass appear to be highly sensitive to changes in environmental conditions. For example, in the decade of 1935 to 1945, eelgrass beds on the north coasts of America and Europe suffered a substantial decline in abundance. The cause of this decline remains unknown but has been ascribed to a variety of causes ranging from parasitic infection by slime mold and fungus to greater than normal changes in rainfall or seawater temperature. A population decline in a wide variety of marine organisms dependent on eelgrass habitat was also seen during this period. Additionally, changes in bottom topography occurred in the affected eelgrass bed areas as currents and wave action reworked formerly stable bottom sediments. Recovery occurred slowly, due to the diminished and scattered distribution of individual plants resulting in reduced vegetative propagation and seed production. Aside from its interaction in the marine and estuarine food webs, eelgrass assumes an important role in cycling

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Eelgrass, Zostera marina Credit: DFG

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northern California. The continued decline of important sh species may serve to offer additional protection for the state’s eelgrass communities by designation of this habitat type as critical habitat under federal laws, administered by the U.S. Fish and Wildlife Service and the National Marine Fisheries Service.

Status of Biological Knowledge The recognition of the importance of eelgrass within the bay and estuarine ecosystem has provided a focus of scientic research and resource management for several decades. Early last century researchers on both coasts collected an array of information on water and air temperatures along with plant data over a several year period. Additionally, measurements of eelgrass standing stock have been conducted throughout the Northern Hemisphere including the West Coast of North America. The distribution of eelgrasses within bay and estuarine ecosystems is dependent on a variety of parameters, including light, temperature, salinity, substrate, waves and currents, nutrients, and availability of seed. Most commonly, estuarine seagrasses are found in soft sediments of semi-sheltered areas where depth and turbidity conditions allow sufcient light. The typical depth distribution of eelgrass is throughout the inter- and subtidal-zones. The maximum standing crop occurs just below mean low water. Maximum biomass occurs at depths corresponding to 20 to 30 percent surface-light intensity. Distribution and abundance of eelgrass also appear to be inuenced along the land-sea axis of estuaries by the relative abundance of nutrients. Nutrient availability is higher at the riverine end of an estuary. However, the mixing zone within estuaries also tends to be more turbid. Thus, the relationship between light penetration and nutrient availability acts with other factors to dene the areas within estuaries where eelgrass beds become established and thrive. Eelgrass is a owering marine plant that grows from rhizomes in soft sediment. The establishment and expansion of eelgrass beds occur through seed production and asexual rhizome propagation. Although their roots and rhizomes help to stabilize sediments where they are established, eelgrass beds are highly susceptible to anthropogenic disturbances, particularly substrate disturbances and reduced light penetration. Eelgrass beds are also susceptible to adverse impacts from non-native invasive species. Studies looking at the response of eelgrass to a non-indigenous mussel (Musculista senhousia) found that eelgrass beds showed a negative response to colonization of this invasive bivalve, particularly where the eelgrass bed was sparse or fragmented, or in beds that had been reestablished. The recent discovery of the invasive algae Caulerpa taxifolia (Mediterranean strain)

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in Agua Hedionda Lagoon in southern California has also demonstrated the ability of an invasive species to displace eelgrass. Once disturbed, eelgrass bed recovery or recolonization is slow and may not be possible without reestablishment of favorable growth conditions. The decline of seagrass and related aquatic vegetation has reached and alarming state worldwide. Studies show documented plant losses in the United States that have approached or exceeded three-quarters of the historic distribution. Further, the importance of genetic distribution in the population dynamics of aquatic plants has in the past largely been ignored in restoration and conservation efforts. Studies in southern California found signicantly reduced genetic diversity in eelgrass beds that were reestablished through transplants or that otherwise became established in previously disturbed locations. Reduced genetic diversity in the transplanted sites corresponded in general to a smaller size and younger plant age than in undisturbed sites, although this characteristic effect on the eelgrass community is not fully understood. However, there was no evidence that genetic diversity increased in transplanted sites over time. It is likely that this genetic diversity problem occurs in many areas of the state where eelgrass bed disturbances commonly take place.

Status of the Beds Along the Pacic coastline of California, eelgrass is found to some degree in all of the larger bays and estuaries, from the Oregon border to San Diego, including Humboldt Bay, Tomales Bay, San Francisco Bay, Monterey Bay, Morro Bay, and San Diego/Mission Bay. Additionally, eelgrass is well established in several of the smaller open estuarine embayments along the state’s coastline. The historical presence of eelgrass along the California coast was much greater than it is today. Although few records exist that measure the areal extent of eelgrass within the state’s small coastal estuaries, the condition that existed prior to human disturbances in many of these locations were no doubt favorable to eelgrass bed communities.

Humboldt Bay Measurements of eelgrass standing stock in Humboldt Bay were conducted in 1972. Distribution was determined by mapping the eelgrass beds through eld surveys and light aircraft. Eelgrass standing stock values determined through density analyses ranged from 3.1 million pounds dry weight in April 1972, to 15.2 million pounds dry weight in July 1972, with South Humboldt Bay accounting for 78 to 95 percent of the total eelgrass stock. These results were similar to an earlier assessment in 1962.

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Small North Coast Estuaries It is likely that at one time eelgrass predominated along the seaward edge of many of the small estuaries at the mouth the north coast river systems. Today, due to human alterations, such as channelization, dredging, and upstream disturbances that cause increase turbidity and siltation, eelgrass is limited to but a few such ecosystems. Remnant populations are documented within the North Coast estuaries that remain open to seawater inuence year-round, such as the Big River estuary where eelgrass forms large beds along muddy banks within the rst three miles of the estuary, and the Albion River Estuary, which also has a well-established eelgrass community.

Tomales Bay Eelgrass is the most abundant marine ora in Tomales Bay. Surveys conducted by the California Department of Fish and Game in 1985, determined the areal extent to be 965 acres. Although eelgrass distribution is relatively stable from year to year in Tomales Bay, densities of eelgrass beds are highly variable within and between individual beds seasonally. The density and distribution of eelgrass within Tomales Bay are determined annually by the California Department of Fish and Game as part of the seasonal herring spawning-ground surveys. Extensive eelgrass beds are located within Tomales Bay throughout the intertidal and subtidal areas, generally in waters less than 12 feet mean lower low water between Sand Point and Nicks Cove, and around the immediate bay perimeter on both shorelines to the vicinity of Millerton Point.

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The general locations of the Tomales Bay eelgrass beds appear to have been consistent since the early 1970s, although there is some annual uctuation. The density of eelgrass during the winter of 1987-1988 was 0.04 0.55 pounds per square foot. Similar densities were observed 1973 and 1976. Such densities represent between 70 and 100 percent bottom-coverage. The long-term evaluation of Tomales Bay eelgrass beds indicates that one bed near the mouth of the estuary is more ephemeral than any other.

San Francisco Bay San Francisco Bay, the largest of California’s estuaries, is also the most impacted by human development. An estimated one third of the historic extent of the bay has been lost to ll and development. While estuarine systems are by nature highly turbid, poor water clarity within San Francisco Bay is further exacerbated by human activities including direct treated industrial and wastewater discharges, non-point source runoff, urban-associated atmospheric deposition, and riverine inow containing urban and agricultural discharges. Data on the historic areal extent of eelgrass within San Francisco Bay are limited, although it is believed that it supported extensive eelgrass meadows in the past. Reduced light penetration due to extremely high bay turbidity has been found to limit the development of eelgrass and may be the principal cause of its decline in San Francisco Bay. Eelgrass beds in the bay today are limited to relatively small patches located in the central bay, Richardson Bay, and the eastern northernmost portions of the south bay. In 1989, the areal extent of eelgrass beds in San Francisco Bay was estimated to be 316 acres. Since that time, some eelgrass beds have increased in size and new patches have been sited.

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The differences in densities between the north and south bays appear to be persistent. A wet-weight density range (depending on location) of 0.06 to 0.43 pounds per square foot for Humboldt Bay winter eelgrass was estimated in 1979. The study attributed eelgrass density differences between the two regions of the bay to variations in sediment composition, and dredging activities in North Humboldt Bay associated with the commercial cultivation and harvest of oysters, rather than light availability or tidal ushing. Localized eelgrass bed density surveys conducted by the Department of Fish and Game in an effort to evaluate the biomass of Pacic herring utilizing Humboldt Bay eelgrass beds for spawning substrate also noted signicantly lower eelgrass densities in North Humboldt Bay compared to South Bay during the 2000-2001 commercial herring season. Total eelgrass coverage within Humboldt Bay was determined to be 3,053 acres in 1984. Since that time, a detailed bay-wide eelgrass survey has not been conducted. However, the California Department of Fish and Game, U.S. Fish and Wildlife Service, Humboldt State University, and others have proposed initiating biannual baywide eelgrass surveys to begin during the summer of 2001.

Eelgrass densities are far lower than those of the larger, healthier beds found in Tomales and Humboldt Bays. Although the eelgrass beds appear to be stressed, they have remained persistent in the bay and are heavily utilized by estuarine organisms.

Southern California The eelgrass communities found south of San Francisco are more heavily impacted by human alteration than those in northern California. Historical records suggest that eelgrass was a predominant plant species in the state’s south coast estuaries. However, the majority of southern California’s remaining eelgrass habitat exists primarily due to replanting or recolonization of eelgrass beds in new or historic locations. Patchy eelgrass communities found within the Monterey Bay Area and Morro Bay are two exceptions. The eelgrass beds within the Monterey Bay Area are limited to the estuarine environment of Elkhorn

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Slough and its entrance to the bay. These areas make up a total of approximately 50 to 75 acres of eelgrass habitat. Eelgrass remains the dominant plant in the beds of Morro Bay. The beds there are the largest and least impacted of any in the southern portion of the state. Nevertheless, there are wide uctuations in areal extent. By 1997, eelgrass distribution reached a historic low of 50 total acres. Further studies in 1998 showed an improvement in eelgrass distribution ranging from 81 to 120 acres, depending on the season of survey. Eelgrass bed communities also exist in Los Angeles Harbor, Huntington Harbor, and in adjacent coastal areas. Many of these have been established through transplant activities associated with specic development mitigation requirements. Due primarily to suitable light conditions, many of the reestablished areas have met their intended mitigation goals. However, some reestablishment attempts have been unsuccessful. A complete survey of the areal extent of eelgrass and associated density assessments within this location of the state has not been conducted. The National Marine Fishery Service and other state and federal resource agencies have conducted cursory surveys of eelgrass in these locations. While formal surveys and reports have not been completed, areas that support eelgrass have been identied. The eelgrass bed communities within San Diego County coastal areas have been heavily impacted by urbanization. All of the bays in this area of the state have been intensively modied. Attendant stresses are evidenced by very low eelgrass densities. Additionally, many of the eelgrass communities in San Diego County coastal areas have been derived through reestablishment efforts or, as in Mission Bay, through natural colonization of dredged sediments. The most comprehensive survey conducted for eelgrass in the San Diego Bay was completed in 2000. This survey followed an early bay-wide survey conducted in 1994. Similar surveys have been completed for Mission Bay, Batiquitos Lagoon, and Agua Hedionda. The location of eelgrass present within Oceanside Harbor has also been documented by the National Marine Fishery Service.

References Harding, L.W. and J.H. Butler. 1979. The standing stock and production of eelgrass, Zostera marina, in Humboldt Bay, California. Calif. Fish and Game. 65(3): 151-158. Hoffman, Robert F. 1986. Fishery utilization of eelgrass (Zostera marina) beds and non-vegetated shallow water areas in San Diego Bay. National Marine Fishery Service, Southwest Region. Administrative Report SWR-86-4. Merkel, K.W. and R. S. Hoffman. eds. 1990. Proceedings of the California eelgrass symposium: May 27 and 28, 1988, Chula Vista, California. Sweetwater River Press. 78pp. Thayer, G. W, D.A. Wolfe, and R.B. Williams. 1975. The impact of man on seagrass systems. Am. Sci. 63: 288-296. Williams, S.L., and C.A. Davis. 1996. Population genetics analyses of transplanted eelgrass (Zostera marina) beds reveal reduced genetic diversity in southern California. Restoration Ecology. 4 (2), pp. 163-180. Wyllie-Echeverria, S., A.M. Olson, and M.J. Hershman (eds). 1994. Seagrass science and policy in the Pacic Northwest: proceedings of a seminar (SMA 94-1). U.S. EPA, Water Division, Wetlands Section. EPA 910/R-94-004. 63 pp. Zimmerman, R. C., J. L. Reguzzoni, S. Wyllie-Echeverria, M. Josselyn, and R. S. Alberte. 1991. Assesment of environmental suitability for growth of Zostera marina L. (eelgrass) in San Francisco Bay. Aquatic Botany. 39: 353-366.

Management Considerations See the Management Considerations Appendix A for further information. Eric J. Larson California Department of Fish and Game

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California’s Living Marine Resources: A Status Report

CALIFORNIA DEPARTMENT OF FISH AND GAME December 2001

History of Harvest Although species in the red algal genera Gracilaria and Gracilariopsis have been harvested throughout the world for agar production and as a food source for humans and cultured shellsh, only small amounts have been harvested from the wild in California during the last few decades. Between 1965 and 1970, several applications were made to the Fish and Game Commission for permission to harvest Pacic herring eggs deposited on edible seaweeds for export to Japan, where it is considered a luxury food item. In 1970, Department of Fish and Game divers conducted a survey to determine the quantity and composition of the aquatic vegetation in Tomales Bay. The commission decided to establish one ve-ton harvest permit each for Tomales and San Francisco bays. However, siltation, which occurs in both bays during the winter months, lowered the market quality of a large portion of the eggs-on-seaweed harvest; as a result, the ve-ton quota was never reached in either bay. The harvest of herring eggs on wild edible seaweed in Tomales and San Francsico bays is now prohibited.

Status of Biological Knowledge Gracilaria pacica and Gracilariopsis lemaneiformis are commonly found in California’s bays and estuaries. Both species have numerous brownish-red thin branches loosely connected to the substrate by a small holdfast and grow to a maximum height around three feet. Because they are so similar in appearance and frequently found growing in the same area, they are often difcult to distinguish. Gracilaria pacica is commonly found in sheltered intertidal to subtidal locations from Alaska to the Gulf of California, Mexico. Gracilaria lemaneiformis occurs in areas exposed to ocean currents as well as protected intertidal and subtidal areas from Vancouver Island, British Columbia, Canada, to Santa Catalina Island in the Southern California Bight. Both species are fast growing and, when detached from the substrate, often form large dense mats in estuarine areas protected from strong currents. In Tomales and San Francisco bays, where annual vegetation density studies are conducted in conjunction with Pacic herring spawning surveys, Gracilaria and Gracilariopsis densities uctuate considerably from year to year.

appear to be among the preferred spawning substrates for Pacic herring in California waters and may be essential to herring when other aquatic vegetation is not available. These beds with herring eggs are an important feeding area for a variety of marine animals.

Management Considerations See the Management Considerations Appendix A for further information. John Mello California Department of Fish and Game

References

Submerged Aquatic Plants

Gracilaria and Gracilariopsis

Abbott, I.A. and G.J. Hollenberg. 1976. Marine Algae of California. Stanford University Press. Stanford. Hardwick, J.E. 1973 Biomass estimates of spawning herring. Clupea harrengus pallasii, herring eggs, and associated vegetation in Tomales Bay. Calif. Fish Game, 59(1) :36-61 Langtry, S.K. and C.A. Jacoby. 1996. Fish and decapod crustaceans inhabiting drifting algae in Jervis Bay, New South Wales. Aust. J. Ecology, v. 21,( n. 3),: 264-271. Spratt, J.D. 1981. The status of the Pacic herring, Clupea harrengus pallasii, resource in California 1972 to 1980. Calif. Dept. Fish and Game, Fish Bull.171. 107 p.

Little is known about the signicance of these species in bay and estuary ecosystems. One study conducted in Jarvis Bay, Australia, found relatively low numbers of sh and decapod species inhabiting drifting Gracilaria spp. beds when compared to adjacent seagrass beds, suggesting that these beds may not be a critical habitat for estuarine macrofauna. However, Gracilaria and Gracilariopsis

CALIFORNIA DEPARTMENT OF FISH AND GAME December 2001

California’s Living Marine Resources: A Status Report

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Submerged Aquatic Plants 492

California’s Living Marine Resources: A Status Report

CALIFORNIA DEPARTMENT OF FISH AND GAME December 2001