LEIGHTON: ABALONE MARICULTURE 



cial take until about 1965. Thereafter both the 

 toll of increased fishing pressure and increased 

 depredation by the rapidly expanding Cahfornia 

 sea otter populations significantly reduced red 

 abalone stocks (Cicin-Sain et al. 1977). A combi- 

 nation of pollution, habitat loss, competition with 

 uncontrolled sea urchin population gi-owth, mor- 

 talities of undersize abalone due to "bar cuts", 

 and increased harvests by both sport and com- 

 mercial divers have had a severe impact on 

 stocks of all species of abalones, especially in 

 Southern California (Cicin-Sain et al. 1977). An 

 important additional element in the decline of 

 California abalone populations hys been the 

 establishment of seasonal closures vvhich do not 

 adequately protect a large portion of the breed- 

 ing populations. The midwinter closure for both 

 commercial and sport abalone harvests (mid- 

 January to mid-March) existed for several de- 

 cades. Since pink (//. corritgata), green, and 

 black {H. crachewdii) abalones spawn from late 

 spring to late fall (Leighton 1974; Tutschulte 

 1975), no reproductive protection was afforded 

 by that measure. Only the deep-water, late- 

 winter to spring spawning white abalone, H. 

 sorenseni, and a fraction of the year-round 

 spawning red abalone populations, were benefit- 

 ted by the California abalone "closed season". 

 Currently, a split closure to include one summer 

 month is enforced for the commercial industry, 

 and also for northern California sport divers. 

 The effect of these measures has yet to be as- 

 sessed. Minimum size limits exist for each 

 species which conserve only the reproductive 

 contribution by young and smaller adults. 



THE DEVELOPMENT OF ABALONE 

 MARICULTURE IN CALIFORNIA 



It is a commonly held misconception that aba- 

 lone culture in the United States was modeled 

 after methods established in Japan. However, 

 little technical information on critical aspects of 

 larval and postlarval culture, of abalone by 

 Japanese biologists was available to the first 

 entrants into the field in the 1960s. Conse- 

 quently, the methods developed for culture of all 

 stages of American abalones are quite different 

 from those practiced in Japan (Leighton 1987). 

 More recently, several attempts have been made 

 in California to apply traditional Japanese 

 hatchery methods, but generally the results of 

 these approaches have not been encouraging 

 (see Hatchery Methods, next section). 



Pacific Mariculture (Pigeon Point, CA) began 



to explore possibilities for culture of abalone as 

 seed for reintroduction to native habitat in 1964. 

 Success was achieved in production of juvenile 

 red abalone. Also, spawnings in tanks holding 

 several species yielded hybrid combinations 

 (Owen et al. 1971; Owen and Meyer 1972^; 

 Leighton 1987). Experimental planting of 

 juvenile abalone was done, but emigration and 

 mortahty at the local offshore site limited re- 

 turns. At the time, the Department of Fish and 

 Game could not grant exclusive fishery rights to 

 in-sea mariculturists for "undersize native" aba- 

 lones. Proprietary "nonnatives" (in this case, 

 hybrids) did poorly in the Pigeon Point area. 

 Accordingly, Pacific Mariculture redu'ected its 

 attention to the production of oyster spat and 

 abandoned further abalone mariculture efforts 

 (B. Owen 1968^). 



In 1967, California Marine Associates (H. 

 Staton, D. Leighton, and J. Perkins) launched 

 the first large-scale abalone mariculture pro- 

 gram in North America with the goal to produce 

 red abalone in land-based tank systems for direct 

 sales to the seafood market. Thousands of seed 

 were provided to the California Department of 

 Fish and Game for their first attempts to plant 

 abalone in the natural environment (Bjornson 

 1970; Bailey 1973). Commercial quantities of 

 young adult red abalone were soon reared in 

 large concrete raceway tanks. Following an in- 

 structive, but problematic, cooperative experi- 

 mental program with the Atlantic-Richfield 

 Company to conduct containment gi'ow-out of 

 abalone beneath an offshore oil production plat- 

 form (Gealy and Lindstedt-Siva 1984^), Cali- 

 fornia Marine Associates was reorganized to be- 

 come Estero Bay Mariculture. In 1982, further 

 reorganization occurred and a new company, 

 The Abalone Farm, Inc., was formed. Refine- 

 ments in the basic culture procedures and expan- 

 sion of the hatchery and raceway systems have 

 boosted production significantly. In 1986, over 

 180,000 small adult red abalone (5-10 cm) were 

 marketed, valued at over $400,000 (F. Oakes 

 1987*=). 



^Owen, B., and R. Meyer. 1972. Laboratory hybridiza- 

 tion in California abalones {Haliotis). Pacific Mariculture, 

 Pigeon Road Point, Pescadero, CA (Unpubl. rep. ) 



""B. Owen, Pacific Mariculture, Pigeon Point Road, Pesca- 

 dero, CA 94060, pers. commun. 1968. 



^Gealy, F., and J. Linstedt-Siva. 1984. Containment 

 culture of abalone beneath an offshore platform. Talk pre- 

 sented at Aquaculture Symposium, May 1984, Southern Cali- 

 fornia Academy of Sciences, Los Angeles. 



"F. Oakes, The Abalone Farm, Inc., P.O. Bo.x 136, 

 Cayucos, CA 93430, pers. commun. 1987. 



691 



