What is abalone? Herbivorous marine gastropod Over 70 species of extant haliotid species
Abalone history in N. America Native Americans-meat, trade material, and decoration Commercial fishery in mid 19 th century Overfishing, disease, poaching, habitat destruction Fisheries shut down
Abalone history in N. America 1980s- first commercial abalone farms in California
Taxonomy Haliotis spp
Taxonomy Haliotis spp
Locations Japan Mexico Australia South Africa Korea New Zealand Taiwan China Chile Ireland Iceland
Locations Japan Mexico Australia South Africa Korea New Zealand Taiwan China Chile Ireland Iceland And of course, California!
Market info California: In 1998 the total amount of abalone produced was approximately 73 metric tons (mt; in-shell weight) of product valued at US$2.4 million (Ebert 2001).
Pricing High pricing in China, Japan, and Koreas In 1994, prices to fishermen in California were $ per dozen for the red abalone. “Abalone can fetch up to $20 per pound or more (Dave Ebert, pers. comm.).”
Reproduction in captivity Males and females induced to spawn ◦ UV irradiated seawater ◦ Solution of hydrogen peroxide Release unfertilized eggs and sperm ◦ 6-8 million ova out of 11 million ova released become fertilized (from one female!) Fertilize, and division starts within 2 hrs
Reproduction in captivity Eggs hatched and reared through trochophore (16-20 hrs) and veliger ( hrs) larval stages All early life stages are sensitive, so UV- treated water is used. Though increased temp can increase development, rearing at 15°C decreases risk of bacterial infection in systems.
Production Methods Cage culture system ◦ Rectangular cages ◦ PVC frames covered with heavy gage plastic mesh ◦ Suspended from longline systems or floating docks
Production Methods Disadvantages: Costs for boat, motor, fuel, access time, and hydraulic wench to lift cages for feeding, maintenance, and harvest And other things we’ve discussed in class
Production Methods Land-based, flow- through tank system: ◦ Concrete or fiberglass tanks of capacity ◦ Tanks plumbed for flow-through seawater and forced air
Production Methods Disadvantages: Operate seawater pumping Aeration systems
Feeds and Feeding Natural diets: ◦ Eggs and larvae: yolk reserves ◦ Juveniles: benthic microalgae (diatoms) ◦ Adults: kelp Artificial diets: ◦ 30-50% protein: fish meal, milk by-products ◦ 30-40% carbs: seaweed ◦ 5-6% each of fat, fiber, and ash ◦ Sometimes mineral and vitamin supplements
Water Chemistry Eggs and larvae: 15°C (59°F) Juveniles: 15 to 18°C Salinity: ppt
Advantages: High densities High production 65% edible part is protein Other nutrients: Selenium, magnesium, iron, and omega-3 fats
Disadvantages: In both production systems, it takes 3-4 years for abalone to grow to market size, about 7-9 cm. Growing to market size is the most capital intensive and time-consuming part of this aquaculture Labor and feed costs A lot of the animal is shell