CURRENT STATUS OF THE CALIFORNIA OYSTER INDUSTRY by

The oyster culture operation in Moro Bay is typical of the United States Pacific Coast Crassostrea gigas mariculture industry. Of this Bay's 1,000 hectares of marshes, tidelands and channels 400 hectares have been alloted by the State of California for private oyster cultivation. Approximately 180 hectares of this allotment are suitable for bottom and stake culture on a three-year growing cycle. Each year this 60 hectares is planted with cultch shell at the rate of 60 cases of cultch per hectare. Each case contains an average of 1,000 cultch shells with 10 oyster spat per shell. A typical survival rate of 30% yields, 3,000 liters of oyster meat per hectare after 36 months of growth. The history of the California oyster industry and the start of mariculture in the state began in San Francisco following the discovery of gold. Along with the quest to strike it rich, the easterners also brought an appetite for their east coast favorite, the eastern oyster, Crassostrea virginica. BARRETT (1963) reported that attempts were first made to bring this eastern species to San Francisco both fresh and preserved, but evidently the few successful shipments could not satisfy the California market. In the 1850's the native Pacific oyster, Ostrea lurida was shipped from Shoalwater Bay (now Willapa), Washington, to San Francisco (BARRETT 1963). This Shoalwater source supplied the greatest part of the San Francisco market, yet a number of other locations in Oregon (Yaquina and Netart's Bays) and Washington's Puget Sound were harvested (HITTELL 1882). BARRETT (1963) indicates that while the oysters were initially sold wholesale and retail, the industry, with its increased size, began organizing and started the practice of holding oysters on suitable mudflats in San Francisco Bay until needed. The completion of the transcontinental railroad linking San Francisco to the east coast marked a time of change in the Pacific coast oyster industry (BARRETT 1963). BARRETT (1963) reported that eastern oysters were immediately imported and soon the Washington source became insignificant. This involved, in addition to adults, the importation of baby (seed) oysters, and marked the beginning of relatively independent oyster production. At Department of Biological Sciences, California Polytechnic State University, San Luis Obispo, CA. 93407. 115 Mar. Res. Indonesia Vol.20, 1977: 115-130 DOI: 10.14203/mri.v20i0.386 THOMAS L. RICHARDS & PHILLIP R. TAYLOR this period BARRETT (1963) reports that the major drawback to sustained mariculture was the inability of the introduced oysters to reproduce in California waters, resulting in a continued need for seed oysters. BARRETT (1963) indicates that this seed mariculture was quite profitable in San Francisco in 1875, and continued to be so past the turn of the century at which time a noticeable decline began. There has been speculation that reports of pollution (EBERT 1973, FREY 1 9 7 1 ) and consequent fear of contaminated oysters played a part in this period of decline, but eventually oysters failed to mature and survive in the Bay (BARRETT 1963). The importation of mature eastern oysters increased as did the imports from Washington (BARRETT 1963). While San Francisco was the center of the organized oyster industry, San Diego, Tomales and Humboldt Bays were approached with varying degrees of success. San Diego Bay was proposed as a location to be involved in the importation of Mexican oysters (BARRETT 1963). The idea was to use the bay for freshening Mexican oysters on their way up to San Francisco (INGERSOLL 1881). TOWNSEND (1893) reported an attempt at raising easterns in San Diego Bay but apparently with no success. Tomales Bay was first used for rearing eastern oysters in 1875 (TOWNSEND 1893) but this effort ceased until the decline of the San Francisco Bay industry (BARRETT 1963). The early industry at Tomales Bay involved seed and full-grown eastern oysters as well as native Olympic oysters (Ostrea lurida) from Washington (BARRETT 1963). Humboldt Bay's early encounters with the culture of oysters fell to failure. In the late 19th century the U.S. Bureau of Fisheries made an unsuccessful attempt at raising oysters and later in the early 1900's the oysters translocated from the failing San Francisco beds met with similar lack of success (BARRETT 1963). In 1902 the Pacific oyster, Crassostrea gigas was introduced to the waters of Washington (GALTSOFF 1932) from Japan, and in 1905 commercial mariculture of this species began (BARRETT 1963). Due to lower costs, lower mortalities, and fine success in its growth, the Pacific oyster has become the principle species of the west coast oyster industry in the U.S. (BARRETT 1963). It was not, however, until the late 1920's and early 1930's that commercial interest in the Pacific oyster in California got started (BONNOT 1935, BARRETT 1963, FREY 1971, EBERT 1973). The Tomales Bay Oyster Company made the initial experimental plantings in 1928 (BARRETT 1963) and in 1929 plantings of seed were made in Elkhorn Slough (BONNOT 1935). The major factor hampering the industry was the dependence on seed oyster imports as Crassostrea gigas, like C. virginica, does not successfully reproduce in the cold California waters (BARRETT 1963, FREY 1971). As a conse116 Mar. Res. Indonesia Vol.20, 1977: 115-130

The history of the California oyster industry and the start of mariculture in the state began in San Francisco following the discovery of gold.Along with the quest to strike it rich, the easterners also brought an appetite for their east coast favorite, the eastern oyster, Crassostrea virginica.BARRETT (1963) reported that attempts were first made to bring this eastern species to San Francisco both fresh and preserved, but evidently the few successful shipments could not satisfy the California market.In the 1850's the native Pacific oyster, Ostrea lurida was shipped from Shoalwater Bay (now Willapa), Washington, to San Francisco (BARRETT 1963).This Shoalwater source supplied the greatest part of the San Francisco market, yet a number of other locations in Oregon (Yaquina and Netart's Bays) and Washington's Puget Sound were harvested (HITTELL 1882).BARRETT (1963) indicates that while the oysters were initially sold wholesale and retail, the industry, with its increased size, began organizing and started the practice of holding oysters on suitable mudflats in San Francisco Bay until needed.
The completion of the transcontinental railroad linking San Francisco to the east coast marked a time of change in the Pacific coast oyster industry (BARRETT 1963).BARRETT (1963) reported that eastern oysters were immediately imported and soon the Washington source became insignificant.This involved, in addition to adults, the importation of baby (seed) oysters, and marked the beginning of relatively independent oyster production.At this period BARRETT (1963) reports that the major drawback to sustained mariculture was the inability of the introduced oysters to reproduce in California waters, resulting in a continued need for seed oysters.BARRETT (1963) indicates that this seed mariculture was quite profitable in San Francisco in 1875, and continued to be so past the turn of the century at which time a noticeable decline began.There has been speculation that reports of pollution (EBERT 1973, FREY 1 9 7 1 ) and consequent fear of contaminated oysters played a part in this period of decline, but eventually oysters failed to mature and survive in the Bay (BARRETT 1963).The importation of mature eastern oysters increased as did the imports from Washington (BARRETT 1963).
While San Francisco was the center of the organized oyster industry, San Diego, Tomales and Humboldt Bays were approached with varying degrees of success.San Diego Bay was proposed as a location to be involved in the importation of Mexican oysters (BARRETT 1963).The idea was to use the bay for freshening Mexican oysters on their way up to San Francisco (INGERSOLL 1881).TOWNSEND (1893) reported an attempt at raising easterns in San Diego Bay but apparently with no success.Tomales Bay was first used for rearing eastern oysters in 1875 (TOWNSEND 1893) but this effort ceased until the decline of the San Francisco Bay industry (BARRETT 1963).The early industry at Tomales Bay involved seed and full-grown eastern oysters as well as native Olympic oysters (Ostrea lurida) from Washington (BARRETT 1963).Humboldt Bay's early encounters with the culture of oysters fell to failure.In the late 19th century the U.S. Bureau of Fisheries made an unsuccessful attempt at raising oysters and later in the early 1900's the oysters translocated from the failing San Francisco beds met with similar lack of success (BARRETT 1963).
In 1902 the Pacific oyster, Crassostrea gigas was introduced to the waters of Washington (GALTSOFF 1932) from Japan, and in 1905 commercial mariculture of this species began (BARRETT 1963).Due to lower costs, lower mortalities, and fine success in its growth, the Pacific oyster has become the principle species of the west coast oyster industry in the U.S. (BARRETT 1963).It was not, however, until the late 1920's and early 1930's that commercial interest in the Pacific oyster in California got started (BONNOT 1935, BARRETT 1963, FREY 1971, EBERT 1973).The Tomales Bay Oyster Company made the initial experimental plantings in 1928 (BARRETT 1963) and in 1929 plantings of seed were made in Elkhorn Slough (BONNOT 1935).The major factor hampering the industry was the dependence on seed oyster imports as Crassostrea gigas, like C. virginica, does not successfully reproduce in the cold California waters (BARRETT 1963, FREY 1971).As a conse-quence, up until 1957 the California oystermen were totally dependent on Japanese sources of seed oysters (BARRETT 1963, DAHLSTROM 1975).Since then natural seed and hatcheries in Washington have supplied an increasing amount of the California needs (EBERT 1973, DAHLSTROM 1975).Seed has likewise been imported from British Columbia in past years (DAHLSTROM 1975).EBERT (1973) also reported that hatcheries have developed both at Pidgeon Point (Pacific Mariculture, Inc.) and at Moss Landing -Elkhorn Slough (International Shellfish Enterprises), the latter being in the pilot stage (DAHLSTROM pers. comm., 1976).These hatcheries hold a potential for supplying an increasing proportion of the California needs.
In Southern California commercial oyster operations were attempted at Newport Bay, Mugu Lagoon, andAnaheim Slough in 1932 (BONNOT 1935), but none of these were financially successful (BARRETT 1963).BARRETT (1963) reported that no recent attempts have been made to commercially culture Pacific oysters in either Mission or San Diego Bays due to the polluted conditions, and efforts undertaken at Catalina Harbor on Santa Catalina Island and at Point Loma in San Diego County apparently proved a failure.
Oysters planted in Elkhorn Slough in 1929 were unsuccessful (BONNOT 1935), but good growth rates were obtained from plantings made in the 1930's (BARRETT 1963).These oysters, planted by the West Coast Oyster Farms, Ltd. were in both bottom and hanging culture.No justification was given for the 1929 failure, but the 1930's results were attributed to the relatively warm waters of the slough (BARRETT 1963).The oysters were abandoned after World War II, and in 1966 the deteriorated water quality forced public health closure (BROWNING 1972, KATKANSKY & WARNER 1974).
The history of the Crassostrea gigas industry in San Francisco Bay was begun in 1933 by the Consolidated Oyster Company.This effort was unsuccessful and by 1939 the venture ceased (BARRETT 1963).Today pollution prevents use of the bay for growing shellfish (FREY 1971).
Bolinas Lagoon was involved in a short-lived attempt by the Charles Johnson Oyster Company to establish a successful allotment in the upper portion of the lagoon.Rapid growth rates were observed, but a Public Health Department ordinance required transplantation of oysters to another area for "purging".This task of transplanting the stocks to the Johnson operations in Drakes Estero prooved economically unfeasible and the allotment was abandoned (BARRETT 1963, GIGUERE 1970).
A number of plantings were made in Bodega Harbor (BONNOT 1938) but because the area lacks certification due to pollution (FREY 1971) no commercial culture has been established there.
Today commercial oyster cultivation is found in Humboldt, Tomales and Morro Bays and in Drakes Estero ( Fig. 1, 2, 3 and 4 ) and Encina Lagoon (FREY 1971, EBERT 1973).The Encina Lagoon operations involves a pilot project of Marine Futures using the heated effluent from a power plant for cultivation of Pacific oyster (EBERT 1973).In addition, commercial hatcheries are in operation at Pidgeon Point, (Santa Cruz) and Moss Landing -Elkhorn Slough (EBERT 1973, DAHLSTROM 1976, pers. comm.).
Humboldt Bay was not a part of the initial Pacific oyster cultivation (BARRETT 1963).The California Division of Fish and Game was attempting the development of an Ostrea lurida industry in the bay, and Crassostrea gigas was prohibited from the bay (BARRETT 1963, MONROE 1973).The ban was lifted and C gigas cultivation was begun (Fig. 1) in 1953 in northern Humboldt or Arcata Bay (BARRETT 1963).Coast Oyster Company initiated this commercial operation and is presently the only company working the area.This commercial culture is the largest oyster producer in the state (Table I).Present cultivation is on an estimated 2,900 acres of county, city and private land (DAHLSTROM 1976, pers. comm.).Bottom culture methods are employed in about ninety-five percent of the cultivation, the remainder is in hanging culture, suspended off the bottom from wooden floats (DAHLSTROM 1976, pers. comm.).
Tomales Bay (Fig. 2) has had a long history of Pacific, eastern and native (Olympia) oyster commercial cultivation (BARRETT 1963).Currently, Crassostrea gigas is the most important commercially, but both the Tomales Bay Oyster Company (FREY 1971, EBERTS 1973) and the Frank Spenger Company (EBERT 1973;DAHLSTROM 1976, pers. comm.)hold mature eastern oysters for the "half shell" market.The 40 acre Tomales Bay Oyster Company's Crassostrea gigas operation located above Millerton Point (Fig. 2) is about ninety percent hanging and ten percent bottom culture (DAHLSTROM 1976, pers. comm.).The half acre bottom culture Frank Spenger operation at Sacramento Landing (Fig. 2) produces for their nearby restaurants (DAHLSTROM 1976, pers. comm.).
Pacific oyster culture in Drakes Estero (Fig. 3) has been successful since the mid 1930's (BARRETT 1963).Currently the Charles Johnson Oyster Company has both state allotments for a total culture area of about 1,000 acres (DAHLSTROM 1976, pers. comm.).The methods are approximately ninety percent hanging and ten percent bottom culture (DAHLSTROM 1976, pers. comm.).
The last significant Pacific oyster growing area in the state is in Morro Bay (Fig. 4).Interest in Morro Bay for oyster culture began in 1932 and during the war years Morro Bay was the state's largest producer (BARRETT 1963).Presently the J.R. Johnson Morro Bay Oyster Company is the only producer in the bay.The acreage used is comprised of an 846 acre state allotment (GERDES et.al 1974) and sixty acres of city land (DAHLSTROM 1976, pers. comm.).Operations in Morro Bay have historically been concerned only with bottom culturing, but presently experimental stake culture is being conducted.
The following gives an indication of the production figures in present day oyster cultivation.Our observations in Morro Bay, based on planting of seed oysters from a variety of sources, have shown spat counts usually ranging from eight to twenty per shell (cultch) and averaging around ten.The seed oysters are received in case units generally with 800 to 1200 cultch per case; most growers planting about twentyfive cases per acre of bottom.Following a growing period of eighteen to thirty-six months the average harvest per case of planted seeds is ten to twenty gallons of adult shelled oysters.Due to lower predation Morro Bay produces an average of from twenty-five to thirty gallons of oysters per seed case.Experimental results (BLAYLOCK& FAIRFAX 1975, unpublished report) indicate higher production rates yet are possible for bottom cultivation in Morro Bay.The shelled oysters are marketed in gallons containing 100 to 120 oysters and in 10 ounce jars containing five to eight oysters.Using average figures from Morro Bay, of the ten thousand seed oysters per case planted only around three thousand (30%) survive to harvest.
Production for the past decade in California has averaged around one million pounds of meat per year (Table I, Fig. 5) while the value of harvests has risen considerably (Table I, Fig. 6) in the 1970's, decline in production has been evident not only in California, but also in Oregon (DEMORY 1975, pers. comm.) and Washington (WESTLEY 1975, pers. comm.)(Table I I , Fig. 5).The prime factor affecting this decline has been the independable source of Pacific oyster seed in past years (DEMORY & WESTLEY 1975, pers. communications;DAHLSTROM 1976, pers. comm.).Japanese sources are unreliable and now contribute less to the fishery (Table III).Seed from other 122 Mar. Res. Indonesia Vol.20, 1977: 115-130   124 Mar. Res. Indonesia Vol.20, 1977: 115-130 Asian countries such as Korea is banned due to disease problems.(DEMORY 1975, pers. comm.).Natural seed production and development of domestic seed hatcheries is increasingly important to the Pacific oyster industry, Washington State seed has been the backbone of the industry in the past few years (DAHLSTROM 1975).British Columbia has also been a source in the past (DAHLSTROM 1975) and has been used in 1976.Commercial quantities of seed from California hatcheries have not been available (EBERT 1973).
California is relatively free of predation problems.Bay ray (Myliobatis californica) predation is controlled by fencing with stakes to protect the thinnershelled young oysters from this pest in problem beds (BARRETT 1963, FREY 1971).Rock crabs (Cancer antennarius) and red crabs (C.productus) prey on small oysters in some growing areas (BARRETT 1963, FREY 1971).The inspection of all shipments of imported oyster seed and adults by the Department of Fish and Game has been relatively successful in controlling Japanese Ocenebra japonica and western Atlantic Urosalpinx cinepea oyster drills in the state of California (FREY 1971).Tomales Bay, however, is one location in which oyster drill predation is a significant factor in seed mortality (KATKANSKY & WARNER 1974).
The principle California Crassostrea gigas diseases are bacteria, fungi, and protozoans (SNIDERMANN & ROSENFIELD 1967). TAKEUCHI et. at. (1960) implicated a gram-negative bacillus in the etiology of mass mortalities of the Pacific oysters from Hiroshima Bay, Japan.Another bacteria is suspected in the "focal necrosis" disease found in seed and adult Pacific oysters on the U.S. west coast (SNIDERMANN & ROSENFIELD 1967).
The fungus Dermocystidium marinum has been found to cause emaciation and mortality in Atlantic and Gulf Coast oysters, and has been shown to be transmitable to the Olympia oyster, Ostrea lurida (SNIDERMANN & ROSENFIELD 1967).No report has been made of this fungus infecting the Pacific oyster, however.
Minchinia nelsoni, (MSX), a haplosporidan plasmodial parasite caused extensive damage to the east coast industry in the late 1950's.Parasites morphologically quite similar to M. nelsoni has been observed in Pacific oysters in Taiwan (SNIDERMANN & ROSENFIELD 1967).
Another parasite found in the Olympia oysters in Washington State and blamed by STEIN et. al (1961) is the flagellate protozoan, Hexamita sp.This form, while not found in California populations of Crassostrea gigas, has been seen in this species from Korea and Taiwan (SNIDERMANN & ROSENFIELD 1967).
Larval trematodes of the genus Bucephalus are known to infect oysters (HOPKINS 1954).Prolonged infectations with Bucephalus causes a retardation of the growth rate in oysters (MENZEL & HOPKINS 1955 a and b).SNIDERMANN & ROSENFIELD (1967) indicated infection of Crassostrea gigas in Taiwan by larval Bucephalus.
Prevention of introduction of exotic parasites is a concern of the industry.Mytilicola orientalis, a copepod parasitic on Pacific oysters is an example of a parasite introduced to California via seed imports.CHEW et. al. (1 9 6 5 ) and KATKANSKY et. al. (1967) reported that infection with this parasite reduced the condition of the oysters.KATKANSKY & WARNER (1974) however, indicate that this parasite is non-pathogenic and not a factor in mortalities in the Pacific oysters of Morro Bay, Elkhorn Slough, Drakes Estero, and Tomales Bay, although infestation in their studies ran from five to forty percent of the oysters sampled.KATKANSKY & WARNER (1974) indicated the mortalities at Morro Bay, Elkhorn Slough and Drakes Estero to be quite low (0-14%) according to experimental studies conducted in the locations.Tomales Bay mortalities (7.6-35.7%)were relatively low compared with the figures from Humboldt Bay in the study, and were not considered excessive.A variety of non-pathogenic parasites were observed in these studies however, including Mytilicola orientalis an endoparasitic copepod, ancistrocomid ciliates, the peritrichous ciliate Trichodina, and encysted cestode plerocercoids similar to Echeneibothrium.Cross infection with "microcell disease" did not occur in Pacific oysters held in proximity to infected European oysters (KATKANSKY & WARNER 1974).
Humboldt Bay Pacific oyster mortalities (averaging 30-40% and reaching 56.4%) are more severe than other areas studied by KATKANSKY & WARNER (1974).This report makes speculations implicating the high mortalities with "inclusion cells", high water temperatures, and/or bacterial diseases.While the causes of high mortalities in Humboldt Bay are yet 127 Current Status Of The California Oyster Industry (Thomas L. Richards & Phillip R. Taylor) uncertain, interest in minimizing the mortality figures has become an important concern of the industry throughout the state.
Obtaining higher survival figures for planted seed oysters, in an economically feasible manner, is being approached in a number of ways.Disease resistant varieties of oysters have been found (FREY 1971).EBERT (1973) and KATKANSKY & WARNER (1974) suggests selective breeding of mortality resistant adults in the hatchery is a feasible method of improving the basic stock.KATKANSKY & WARNER (1974) studied the differential mortalities exhibited by seed from various import sources in order to determine the more successful types.Their findings showed significant differences among seed sources.
Inovative methods of cultivation could decrease mortality rates and allow additional improvements in growth rates and quality.KATKANSKY & WARNER (1974) found significantly improved results in rack culture (approx.20%) mortalities compared with the ground culturing method (approx.55%).WESTLEY (1975, pers. comm.) reported similar results in experimental combinations of tray and ground rearing in Washington State.
Reversing the declining production trend is primarily a matter of economics.Methods of increasing production have been illustrated by researchers, and the present allotments potentially allow for the use of additional cultivation areas.A stable domestic seed supply is necessary for the fishery to grow, as imports are not always available.Threats to the California oyster industry may exist in the area of pollution, which has shown its effects in the past, but with the enforcement of new laws and regulations new areas may become available for oyster production.Possible problems related to recreational land-water use and increasing population will still remain in some areas preventing or restricting the industry's growth.The industry has, however, been adaptable in the past, and with an increasing interest in the sea for food resources, there seems no reason why oyster mariculture in California will not provide us with this resource in increasing quality and quantity.

ACKNOWLEDGEMENT
We would like to acknowledge our thanks to WALTER A. DAHLSTROM of the California Department of Fish and Game, DARRELL DEMORY of Oregon's Department of Fish and Wildlife, and RONALD E. WESTLEY of Washington's Department of Fisheries for their interest and assistance.