STATUS OF FARMING OF SELECTED SPECIES- MARINE

FINFISH, SHELLFISH, SEAWEEDS AND OTHER INVERTEBRATES

• Japanese amberjack (Seriola quinqueradiata)- 17% Asian marine fish production

• Other carangids snub-nosed pompano (Trachinotus blochii) and silver pomfret (Pampus argenteus).

Marine finfish

Trachinotus blochii Pampus argenteus

• Seabreams

• Barramundi or Asian seabass (Lates calcarifer)cultured in both brackishwater and mariculture

• Grouper high prices in the live fish markets of Hong Kong SAR and the People’s Republic of China

• Bluefin tuna (Thunnus maccoyii) Cultured in Australia; high demand in Japanese market

• Cobia (Rachycentron canadum) Production comes from China PR and Taiwan Province of China Grows 6kg/yr; High demand in Asia and America Set to become the global commodity

• Milkfish (Chanos chanos) Traditionally cultured in Philippines; seed production- Indonesia (major usage as bait in tuna fishery)

• Many depend on wild capture

• Need for seed production/ hatchery technology

• Asia- small scale or backyard hatcheries;

• Australia and Japan- technology dependent hatchery ; mainly to reduce labour input

• Taiwan PC - a major seed stock production centre for the Asia-Pacific region

• Taiwan PC is typified by highly specialized production sectors

Seed stock production

• Substantial mortality in the juvenile seed stock mainly because,

– Cannibalism among the hatchery reared juveniles

– During transportation

Nursery

• Asia-Pacific region -small floating or fixed cages to extremely large cages (15x15x15 m)

• Large cages for amberjack grow-out (Japan) or 30–50 m diameter circular cages for southern bluefin tuna grow-out in Australia

• Asia-Pacific region - small to medium-scale farms.

• Many farms use relatively simple technologies, with wooden or bamboo cages and plastic barrels or polystyrene blocks to provide buoyancy.

• Japan and Australia- sophisticated cage sysytems

Grow out

• Most shrimp and crustacean -in coastal ponds and thus does not meet the definition of “mariculture”

• Tropical spiny rock lobsters (Family Panuliridae)(Panulirus ornatus)- Southeast Asia, Viet Nam and the Philippines

• Viet Nam- 1500 tonnes- fixed, floating and submerged net cages are used

CRUSTACEANS

• Seed- wild

• Viet Nam-coconut logs are drilled with holes to provide an artificial substrate for puerulus/juvenile settlement.

• • Once settled, the juveniles are removed from the logs and placed in nursery cages

Food and feeding

• Lobsters fed on fresh fish and shellfish- 70 % fish and 30% shellfish.

• Preference for lizardfish (Saurida spp.)

• Juveniles-fed with chopped fish 3–4 times per day. Larger lobsters -1–2 times per day and fish is fed whole.

• The food conversion ratio (FCR) for lobsters fed this diet (fresh weight basis) is around 17–30:1

• Philippines- stocking size 100–300 g

• Takes 6–15 months to reach size of 0.8–1.3 kg.

• Survival 90%; smaller lobsters (30–80 g) 50 %

• In Viet Nam -18–20 months to culture juveniles (1–2 g) to the preferred harvest size of about 1 kg

Stocking density

• Bacteria - Aeromonas hydrophyla and Proteus rettgeri

• Fungi - Fusarium solari and Lagenidium sp. and l. Zoothamniun and Vorticella

Disease

• Mussel- a high-volume, low-value commodity

• Green mussel (Perna viridis)- In Asia-Pacific region, Thailand and the Philippines are large producers

• Pearls- low-volume but high-value product

• collection of seed stock from the wild.

• Artificial settlement substrates such as bamboo poles, wooden stakes, coconut husks or lengths of frayed rope -to collect bivalve spat at settlement.

• The spat may be transferred to other grow-out substrates or cultured on the settlement substrate.

Molluscs

There are three major systems commonly used for bivalve culture

1. Within-particulate substrates – to culture cockles, clams, etc.

2. On or just above the bottom- for culture of bivalves that tolerate intertidal exposure, such as oysters and mussels

3. Surface or suspended culture - Bivalves are often cultured on ropes or in containers, suspended from floating rafts or buoyant long-lines

Management of the cultures :

1. Thinning the -to support optimal growth and development,

2. Checking for and controlling predators, and controlling biofouling

• Tropical mussels grow to market size (about 5–7 cm shell length) in <1 yr or in 6–7 months, after settlement.

• Production -1 800 t/ha annually but may be lower in some areas.

• With a cooked meat yield of around 20 %, this is equivalent to 360 t of cooked meat / ha /year

• yesso scallop (Pecten yessoensis)- China and Japan

• Production -1.1 mt in 2003

• Giant clams (Tridacnidae) - In Pacific Island countries

• Tridacnid clams- slow growth- extensive culture

• Tridacnid clams- Mainly in ornamental market

• Pearl oysters -Japan, China, Australia, Indonesia,several Pacific Island nations- French Polynesia and the Cook Islands

• Technically intensive

• Culture period- 9 months to 3 yrs

• Pearl oysters are - suspended culture systems in which oysters are usually suspended below rafts or on long-lines

• edible bivalves -human health concerns- filter feeding

• Improving the quality- by depuration

• Constraint- limited demand and low price

• Most cultured- - Temperate Japanese sea cucumber (Apostichopus japonicus) - Tropical sandfish (Holothuria scabra)

• Farming of A. japonicus -northern China

• Most production -earthen ponds, also some mariculture using sea cages on the substrate or suspended below rafts

• The sea cucumbers are fed Sargassum and other macroalgae

• Southern China - Holothuria scabra, H. nobilis and H. fuscogilva (Chen, 2004)

SEA CUCUMBERS

• Indonesia, H. Scabra- cage farming - 20x20 m or 40x20 m in shallow (0.75–1.0 m deep) coastal areas or in coastal fish ponds

• Organic material (rice bran and animal dust) is added at 0.2–0.5 kg per m² every two weeks

• Holothuria scabra grows slowly- harvest weight of 200–250 g in 6 months

• Seedstock - from wild

• Well established in China for A. japonicus

• Difficulties in accessing suitable broodstock and low rates of survival to juvenile as constraints to hatchery production of H. scabra in Indonesia

• Sandfish require large areas for nursery and grow-out phases because growth rapidly becomes limited as density increases

• For this reason, there has been considerable focus on their use for sea ranching

Production technology

• The demand in China exceeds supply

• Because Chinese view sea cucumber as having medicinal properties, as well as being a delicacy

• The price of bêche-de-mer (A. japonicus) increased from RMB 500 per kg in the 1980s, to RMB 600–1 000 per kg during the 1990s, to around RMB 3 000 (approximately US$400) per kg in 2003

Market

• Sponge aquaculture - commercial production of farmed sponges in the Asia-Pacific region is low

• Small commercial farm - Pohnpei (Federated States of Micronesia) and several experimental operations in Australia, New Zealand and the Solomon Islands

• sponges can be propagated vegetatively with little infrastructural neccessity

Sponges

• The harvested product (for bath sponges) can be dried and stored

• Market acceptance and economic viability of commercial sponge farming has not yet been established

• Further assessment of basic biological parameters such as growth and survival, as well as development of marketing channels, is necessary before large-scale sponge aquaculture can be developed.

• Small-scale development of coral farming in the Pacific Islands• Both soft and hard corals have been cultured, primarily for the marine

aquarium trade, although some hard corals are sold as curios or used for restoration of degraded areas on coral reefs

• Corals are propagated vegetatively. Small pieces of live coral are glued to bases, and these are placed on underwater “tables” fitted with galvanized wire mesh

• Growth is reportedly rapid, with aquarium corals reaching harvestable size in 3–12 months.

• Because of the low level of capital investment needed and the relatively simple propagation methods used, coral culture is suitable for remote coastal communities where infrastructure may be lacking

Corals

• Aquatic plants - major production component of mariculture in the Asia-Pacific region

• China -largest producer, producing just less than 10 million tonnes• The dominant species is Japanese kelp (Laminaria japonica)

SEAWEEDS

• The brown algae L. japonica and Undaria pinnatifida, the red algae Porphyra, Eucheuma, Kappaphycus and Gracilaria, and the green algae Monostrema and Enteromorpha

• Seaweeds are grown for:-direct consumption, either as food or for medicinal purposes; -production of the commercially valuable polysaccharides alginate and

carrageenan; -use as fertilizers; -feed for other aquaculture commodities, such as abalone and sea

urchins.

• seaweeds reproduce vegetatively -cuttings

• Grow-out is undertaken using natural substrates, long-lines, rafts, nets, ponds or tanks

• Existing technologies rely on tying individual plants to lines and are time-consuming and limit production

Production technology

• “Green rot” and “white rot”, caused by environmental conditions, particularly light levels

• “Ice-ice” disease in Eucheuma/Kappaphycus, associated with low light levels and reduced salinity

• Epiphytes that compete with cultured seaweeds for nutrients and may block light to the thalli

• Infections of bacterial and mycoplasma-like organisms

• Cultured seaweeds are often consumed by herbivores, particularly sea urchins and herbivorous fish species such as rabbitfish (Family Siganidae)

DISEASES

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