10 abalone culture 8 allsopp2011

The strong traditions surrounding abalone consumption in China have created a stratifi ed market, based on perceived quality differences between popular brand names and countries of orig

8 Abalone Culture

Mark Allsopp , Fabiola Lafarga - De la Cruz ,

Roberto Flores - Aguilar and Ellie Watts

8.1 INTRODUCTION

Abalone is a prized seafood delicacy worldwide Abalone are marine gastropod molluscs

of the family Haliotidae, also called sea snails, ear - shells or sea ears They possess a single shell, which is a low open spiral structure, and a large muscular foot that is used to attach

to hard surfaces The family Haliotidae contains one genus, Haliotis , and about 100 species

are recognised worldwide (Jia & Chen 2001 ) More information on the biology of abalone can be found in Jia and Chen ( 2001 )

Aquaculture activities have grown considerably in the past decade, increasing their contribution to the global market as fi sheries continue to decline worldwide Abalone aquaculture industry has rapidly developed from about 3,000 tons in 2000 to over 40,000 tons in 2008 (FAO 2010 ) The principal countries producing cultured abalone are China, Korea and Taiwan Several other countries including Australia, Chile, Mexico, New Zealand, South Africa, Thailand and the United States are also developing abalone aqua-culture industries With the maturity of production lines from farms worldwide the industry has established markets in mainland China through Hong Kong, Japan and Singapore The demand for cocktail - size abalone has driven the expansion and development of the industry throughout the producer countries A variety of abalone species are cultivated around the world (see Table 8.1 )

8.2 THE ABALONE MARKET

The two largest consumers of wild and cultivated abalone are China and Japan Generally the Chinese prefer a lighter coloured ‘ foot ’ and the Japanese a darker one; a characteristic

Recent Advances and New Species in Aquaculture, First Edition Edited by Ravi K Fotedar, Bruce F Phillips.

© 2011 Blackwell Publishing Ltd Published 2011 by Blackwell Publishing Ltd.

that varies between species The preferred size category is between 200 and 300 g per abalone, but most cultivated abalone are sold at between 50 and 150 g

8.2.2 Mainland China

Mainland China is the largest consumer of abalone, a fact that often remains unrecognised because consumption of abalone in China is almost entirely in the canned form In regions such as Japan and the USA, canned abalone is generally not considered a premium product Canned abalone has a traditional place in Chinese society as an item of prestige, often presented as a show of affl uence or a demonstration of respect Considered customary in banquets and traditional feasts, a single can of abalone is often given as a token of respect The strong traditions surrounding abalone consumption in China have created a stratifi ed market, based on perceived quality differences between popular brand names and countries

of origin The major distribution point for canned abalone destined for mainland China is through Hong Kong (Oakes & Ponte 1996 )

Table 8.1 Abalone species cultivated around the world

Australia Haliotis laevigata and Haliotis rubra 504

New Zealand Haliotis iris and Haliotis australis 8

China and Taiwan Haliotis discus hannai 33,010

Taiwan Haliotis diversicolor 348

Korea Haliotis discus , Haliotis discus hannai ,

Haliotis diversicolor , Haliotis diversicolor supertexta

5,146

Japan Haliotis discus hannai NA

Thailand Haliotis asinina 30

South Africa and Namibia Haliotis midae 1,040

Chile Haliotis discus hannai , Haliotis

rufescens

515 Mexico Haliotis rufescens, Haliotis fulgens,

Haliotis corrugata

60 USA Haliotis rufescens , Haliotis fulgens,

Haliotis corrugata

175 Canada Haliotis kamtschatkana NA

Ireland Haliotis tuberculata NA

Note: NA = No data available

* Production data obtained from FAO Fisheries and Aquaculture Information and Statistics Service website

8.2.3 USA

In the USA there is a traditional market for abalone, which is mainly in California, where there was a fl ourishing fi shery until the early 1970s In the California market tradition, abalone are removed from the shell and sliced into steaks, which are tenderised and then fried At one time in California, abalone was an abundant, low - cost regional delicacy, but

as the fi shery dwindled due to over - harvest, constricting supplies caused the market price

to increase to a level that has severely restricted demand for the product The traditional

US market now consists primarily of expensive, white tablecloth restaurants in California The emergence of Asian communities as a signifi cant abalone market in major US metro-politan areas has spurred the demand for specialty food products This has kindled a demand for Asian - style abalone products in the US market The market niche is mainly for fresh abalone meat used in Japanese sushi, but a brisk market for live cultured abalone has developed in recent years (Oakes & Ponte 1996 )

8.2.5 Europe

Although Europe is not a major market area for cultured or fi shery - caught abalone, there

is a regional demand arising from the traditional fi shery for H tuberculuta This market is

concentrated in France, but there is some demand throughout the UK and the rest of Europe This demand is generally under - supplied and could be developed if supplies were available The European abalone species are small and traditional product presentations are well suited to the smaller (100 g) abalone produced by culturists Therefore, this region is of great interest for future market expansion

8.3 ABALONE PRODUCTION TECHNOLOGY

Though culture of abalone has developed in several countries, this section focuses on developments in South America, Australia and New Zealand

8.3.1 Chile

In Chile, aquaculture is an important income source for the economy It produced nearly 853,000 tons with a value of US$5.3 billion by 2007, positioning Chile among the top ten

world aquaculture producers (FAO 2009 ) Among the aquaculture resources exploited in Chile, abalone was introduced in the late 1970s as a means of diversifi cation, taking into consideration its high commercial value and an unsatisfi ed demand worldwide (Flores -

Aguilar et al 2007 )

Currently, the abalone industry is supported by two foreign species: Haliotis rufescens , red abalone from California and Japanese or ezo abalone, Haliotis discus hannai from

Japan Red abalone was fi rst introduced in 1977, for experimentation in closed systems by

Fundaci ó n Chile and Universidad Cat ó lica del Norte (UCN) (Godoy et al 1992 ) Later, in

1982, UCN introduced and adapted the culture technology of the Japanese abalone in laboration with the Japan International Cooperation Agency (JICA) However, abalone culture technology transfer began only in 1992, when red abalone culture was authorised,

col-in the sea off Chilo é Island col-in southern Chile, for a subsidiary company of Fundaci ó n Chile Japanese abalone commercial culture started in 1996 in northern Chile where several com-panies adapted the technology for land - based culture, as abalone seed were provided by the UCN ’ s Center of Abalone Production The fi rst offi cial red (1 ton) and Japanese abalone (8 tons) production were registered by the Undersecretary of Fisheries of Chile, in 1998 and 2003 respectively Exports began in 1999 with 36 tons of red abalone

Currently, there are 19 farms in operation (11 in the north and eight in the south) Seed production is mainly in the northern region, while most growout systems are land - based in the north and in - water in the south of Chile Since 2002, Chilean legislation has allowed both species to be cultured in land - based semi - closed systems, while red abalone may also

be cultured in water - suspended systems between Seno del Reloncavi and Skyring Peninsula

in southern Chile (Resolution 30 September 2002) On the other hand, since 2004 the culture of both species has been permitted in the sea but only in two of the three actual culture regions located in northern Chile, and the stock has to be single - sex individuals and sited over a soft substrate area (Subpesca 2006 )

Currently, Chile is positioned as the fi fth abalone producer worldwide with a production volume of 479 tons and an estimated value of US$11.5 million Red abalone production accounts for 97.5% of total production, as this species has been well adapted to full - cycle culture in northern and southern Chile (Enr í quez & Villagr á n 2008 ) On the other hand, Japanese abalone has not adapted well because of its minor resistance to the Chilean culture conditions (i.e water temperature and type of macroalgae availability) and is actually con-sidered as an emergent species (less than 5 tons a year) Unfortunately, no other abalone species have been introduced, because Chilean legislation allows only these two species

to be imported and cultured, and efforts to introduce new exotic species (not endemic) had been laborious, time consuming and unsuccessful However, research on hybridisation between red and Japanese abalone has proved to be potentially important to diversify and

to improve the Chilean abalone industry Moreover, abalone farming can be considered a young industry, with 70% of the farms just starting the phase of commercialisation and exportation

8.3.1.1 Conditioning and s pawning i nduction

Abalone culture technology in Chile is fully integrated in the northern region, where ery, nursery and growout operations are undertaken by most of the farms Only two of all the southern farms possess all culture phases, and the rest are only in - water growout facili-ties that are provided with red abalone seeds in the range of sizes of 15 – 25 mm by northern

hatch-farms Hatchery facilities are composed of a broodstock area, a spawning area and a larval rearing system

Adult abalone are maintained in a specially designed unit, separated by sexes at stocking biomasses of 25 g/L, in continuously running water at ambient temperature and normal photoperiod 12D:12L Water is usually fi ltered up to 25 μ m, but some farms use 50 μ m Acceptable water quality parameters are: water temperature 12 – 20 ° C, pH 7.4 – 8.5, dissolved oxygen 7 – 10 mg/L, alkalinity 120 – 180 ppm, salinity 34 – 36 psu, ammo-nium 0.0 – 0.02 ppm, nitrite 0.0 – 0.2 ppm and nitrate 0.0 – 2.0 ppm Feeding rates are around

10 – 20% of body weight per day, supplied with a fresh mixed macroalgae diet made up

mostly of Macrocystis sp (90%), Lessonia sp., red algae Gracilaria sp and green algae Ulva sp

Spawning adults normally used are 2 to 6 years old, with a visual gonad index of 2 + to

3 + If hybridisation is desired red abalones of 2 – 4 years old should be used to improve fertilisation and hatching rates (unpublished data) Spawning induction is usually under-gone by chemical stimulation using doses of TRIS - H 2 O 2 reactive (Morse et al 1976 ) in

UV - irradiated water fi ltered at 1 μ m after 1 hour of desiccation at ambient temperature But temperature and UV induction are also applied in some facilities, normally by raising temperature gradually up to 5 ° C at rate of 1 ° C /hour Normally, females are induced 15 – 30 minutes before males, but if hybridisation is undertaken males should be induced at least

15 minutes before females, to assure sperm availability as the fertilisation window for cessful hybrid crosses is less than 20 minutes At increasing egg age fertilisation rates drop

suc-sharply (Lafarga - De la Cruz et al 2010 )

Female gametes are collected, and fertilisation is done in 20 L containers with sperm concentrations in the order of 10 6

sperms/mL for homospecifi c crosses, and 10 7

sperms/mL

for heterospecifi c crosses (Lafarga - De la Cruz et al 2010 ), and contact times around 2 – 6

minutes Fertilised eggs are rinsed several times by decantation with UV - irradiated water Finally, fertilised eggs are placed forming a monolayer at the bottom of the hatching tanks (50 – 100 L) and left static overnight, in a controlled - temperature room (17 ° C)

After 16 – 18 hours, trocophore larvae hatch out and they are collected and selected ( > 150 μ m) in upwelling tanks for its larval culture period of 5 to 7 days, depending on water temperature Antibacterial treatments are recommended daily during this period, as well as maintenance activities Normal larval development is followed daily by microscopic observations Both closed systems and fl ow - through systems are used for larval culture, and when the abalone larvae are competent (observation of the third tubule in cephalic tentacles, and characteristic larvae ’ s foot movements) they are transferred to the post - larval and juvenile tanks

8.3.1.2 Nursery t echnology

The nursery facility for rearing abalone from post - larval to juvenile seed size (17 – 28 mm)

is based on the Japanese plastic plate system for larval settlement (Fig 8.1 ) Preconditioning

of plates is normally with naturally occurring diatoms, but some farms also use cultured

microalgae (mainly Ulvella sp., Cocconeis spp and Navicula spp.)

Abalones remain in nursery between 3 and 10 months, depending on the type of culture system used Land - based systems use abalones of 10 – 15 mm in shell length into the produc-tion system, where they are maintained for 24 – 48 months On the other hand, in - water (non - land based) systems use slightly bigger animals (20 – 25 mm) for grow - out

8.3.1.3 Growout t echnology

Abalone farms in the north are characterised by land - based growout operations employing

a substantial infrastructure; with many raceway tanks (Fig 8.2 ) and integration of all phases

of production

The growout tanks are 10 × 1.5 × 0.7 m, made of fi breglass, with a total volume around 11,000 L, with compartments having a conic - shaped bottom to facilitate the cleaning process They have 6 baskets inside (1.5 × 1.5 m and 0.6 m) (Fig 8.3 ), made of plastic mesh (6 mm hole diameter) and plates where the abalone is attached This makes a total surface

of 100 square metres available for the abalone, and the plates hold the organisms off the bottom where the waste debris from the abalone and algae is accumulated A 1 mm thick HDPE plastic plate covers each basket and weights are added on to keep the shelters inside the water Ambient temperature seawater is used in a fl ow - through system The seawater exchange rate is 9 tons per hour, and fi ltered seawater to 90 μ m is used Air is pumped to each tank constantly

The main food for growing out abalone is brown algae Three brown algal species are

normally used: Lessonia trabeculata , Lessonia nigrescens and Macrocystis integrifolia , with L trabeculata being the most abundant In the north, there is a regulation that only

registered companies may harvest kelp and they have to comply with scientifi c management regulations in order to maintain the sustainability of the resource Most of this kelp is

Fig 8.1 Japanese plate system for post - larval and juvenile culture

Fig 8.2 Raceways growout culture system (P Camanchaca Company, Caldera Chile)

harvested at low tide and is cut with a knife by fi shermen holding contracts with these companies

The capacity of abalone per basket and shelter is constant and the number depends on

the abalone size Two times a week the abalone are fed ad libitum , and the cleaning of the

tank depends on the time of the year and the algal feed but is normally once a week The tank is emptied and the tank surfaces are scrubbed with a brush and then refi lled with fresh seawater

Most of the land - based abalone aquaculture farms in Chile monitor water quality as temperature and oxygen once a day, and salinity and phytoplankton and bacteria at least once a month In compliance with the regulations of the federal agencies (Decreto Supremo

No 90/1996 Ministry of Economy), levels of suspended solids, oxygen, ammonia and temperature amongst other factors have to be continuously monitored The exact monitor-ing requirements and their frequency varies, however, according to the size and location

of the farm and type of feed used

In the south of the country, sea - based growout systems are widely used The small farmers use the barrel culture system (Fig 8.4 ), and only the larger production companies with inventories over 2 million abalone use cage - based growout systems These are either plastic moulded cages or iron - galvanized structures covered with netting The cage size is normally 2 × 1 × 1 m, but the most advanced cages are 3 × 1 × 1 m These cages (Fig 8.5 ) have vertical plates as surface for the abalone to attach In these plates a maximum capacity

of 65% of the total surface area of abalone is allowed

Fig 8.4 Barrel abalone growout system

Fig 8.3 Baskets with shelter plates for juvenile culture

These containers are suspended in a typical long line, and the kelp Macrocystis pyr í fera

is the most widely used algal species to feed abalone To operate the culture containers the

bigger farms use barges with a hoist to lift the cages The Macrocystis feed is harvested

from small boats and cut with a knife On the small farms staff collect the seaweed

manu-ally, while the bigger companies pay local fi shermen to supply the algae Macrocystis is

abundant in summer, but almost disappears in winter, forcing farmers to purchase cultured

red algae, Gracilaria chilensis While there is constant supply of cultivated Gracilaria in the south, the growers claim that Macrocystis produces much better abalone growth rates

No kelp harvest permits are required in the southern regions

Artifi cial feeds are used in some phases of the abalone growth, especially in land - based farms in the north, in both nursery and growout operations At some land - based farms, abalone of all sizes receive a combination of artifi cial and kelp diet

No manufactured diets are used on the in - water farms because environmental regulations restrict aquaculture operations using formulated feeds As a result of the large - scale salmon culture in the region, aquaculture operations using pelleted feeds are deemed ‘ intensive ’ farms and sea concessions will only be granted if they are a minimum of 2.8 km from neighbouring concessions This makes it very diffi cult to fi nd suitable areas for abalone culture that comply with this regulation As a result all farms in the south use seaweeds

as feed

One company in the north has experimented with a recirculation system for more than

fi ve years and it is proving very successful

Fig 8.5 Abalone growout cage with its HPDE plastic plates

8.3.2 Australia

In 2008, abalone aquaculture emerged as one of the fastest - growing agribusiness sectors

in Australia With 850 tons produced in 2006/7, worth AU$42.5 million to the Australian economy, this is estimated to grow to 1,500 tons over the next fi ve to ten years, worth $75 million (Fleming 2008 )

8.3.2.1 Conditioning and s pawning t echnology

Until recently it had been assumed that Australian abalone farmers have found it far more reliable to collect conditioned animals from the sea rather than condition them in tanks (Fleming & Roberts 2001 ) However, high - quality gametes can now be obtained in winter

from H laevigata held in a fl ow - through broodstock system developed by researchers from the Western Australian Fisheries Department and industry (Freeman et al 2006 )

Water temperature is considered the main exogenous factor that regulates the

reproduc-tive cycle of abalone (Landau 1991 ; Hone et al 1999 ; Fleming & Roberts 2001 ; Maguire

2001 ; Plant et al 2003 ) Fleming and Roberts (2001) indicated that for H rubra

tempera-tures between 15 and 17 ° C are optimal In a study undertaken at Ocean Wave Seafoods

farm at Lara, Victoria, Plant et al (2003) determined that H rubra can be brought into

spawning condition when kept at constant temperature (18 ° C) The best spawning results were achieved after 120 days, when about 2 million eggs were spawned per female in 60%

of those tested, with a 75% fertilisation rate The results clearly showed that conditioning

at a constant, increasing temperature delivers an increase in spawning success The ers believe the process should be applicable to other species

Fleming and Roberts (2001) found that temperatures between 17 and 19 ° C were optimal

for conditioning H laevigata In Western Australia, Freeman (2001) has found that H

laevigata can be spawned all year round when water temperatures in the conditioning

room ranged from 14.2 – 19.23 ° C The most successful spawning events with highest egg productions occurred out of the ‘ natural spawning season ’ in most groups Spawning events during this period can be highly benefi cial to farmers as they can take advantage of the enhanced growth of juveniles during the early summer months Animals can be weaned off the plates before the highest summer temperatures occur High water temperature during the weaning process can cause high mortalities in some regions of South Australia (Maguire 2001 )

Abalone can be stimulated with a single stimulus, or a combination of stimuli including temperature changes, treating seawater with UV, ozone or hydrogen peroxide, handling animals, or exposing them to air, depending on the species of interest (Maguire 2001 ) Hone

et al (1999) outlined the procedure for spawning H laevigata as follows: place the abalone

in clear aquaria and reduce the light and noise levels After a few hours of acclimation in ambient temperature water, activate the UV fi lter If after 5 hours there is no activity, further stimulate the abalone by placing an immersion heater in the tanks and rapidly raise the temperature by 3 – 5 ° C

8.3.2.2 Hatching

Fertilised eggs from H laevigata hatch after approximately 16 hours at 18 ° C and are called

trochophore larvae Newly hatched trochophore larvae swim to the surface and then can

be easily separated from the unhatched eggs and discarded egg cases by decanting off the