Commodities

Corals

  • Name of species:
    Scleractinian corals.
  • Primary potential:
    Aquarium and curio coral trades, coral reef restoration, and enhancement of snorkeling trails for ecotourism.
  • Attributes for aquaculture/stock enhancement :

    While scleractinian corals are CITES listed and require permits etc., aquacultured corals qualify as 'captive bred' and are exempting from CITES regulations, but only if they are certified as grown from second generation cultured stock.

    · Coral 'seed' are readily available in the wild; however, wild stock should only be relied on in the selection of fragments for culture into 'mother colonies'

    · Selection for colour, growth form, disease resistance, attachment and growth rate should be done in initial trials before culture into mother colonies

    · Coral culture is a central component of the 'green certification' process for the aquarium and curio trades, phasing out the wild coral harvest over time

    · High rates of survival (close to 100%) when coral seed are handled properly

    · Fast production (3-12 months for aquarium corals, 1-3 years for curio corals)

    · Cultured corals have high retail prices, higher than for wild collected coral

  • Culture methods :

    Corals can be grown in shallow water in the field with relative ease without the use of scuba, as long as the culture site has (1) good water flow but is sheltered from waves, (2) consistently high quality seawater, (3) abundant shelter for herbivorous fish, which are important for cleaning the frames

    · Underwater 'culture tables' are constructed of ½ inch (12 mm) metal bars wired together with baling wire (similar to WorldFish Center clam culture tables), for holding the 'culture frames' of coral fragments. Extra bars can be attached to form 2-3 layers

    · Culture frames are made of 1 x 1 cm galvanised wire mesh, painted to prevent rusting. Dimensions may vary but must be sufficient to allow for overlap and stability on the culture table

    · Bases for culture can be made of concrete disks, rock or shell

    · 3-5 cm coral fragments serve as seed. A 30 lb (14 kg) breaking strain monofilament line holds the seed fragment tightly to the base and the base to the frame. A single frame can hold about 50 fragments for culture, and 10-12 frames per culture table

    · Corals can be grown at high densities, lessening negative impacts on reef environments.

    · Coral fragments can also be cultured directly on clean rubble beds, with each fragment tagged to establish its cultured nature

    · Mother colonies can be cultured on lines stretched between the culture tables, attached to concrete blocks, or directly on clean rubble

    · Each coral farm should have an associated restoration or reef enhancement site, for receiving unmarketable corals (misshapen, partly dead or broken)

  • Current production status :

    · Much research remains to be done to improve methods

    · Pilot-scale production is occurring in several places in Fiji (Walt Smith and Foundation of the South Pacific) and in the Philippines and Palau using different methods and requiring scuba

    · Commercial production took place in Marau Sound, Solomon Islands in 1998-99, but most of this activity was curtailed by ethnic unrest in 1999-2000

  • Marketing :

    · Well-established, long-standing international demand

    · Domestic demand by the tourism industry for small bleached or coloured corals, estimated at up to 50,000 aquacultured colonies per year in Fiji Islands alone· An opportunity to develop a local product of high value, and for use with communities for conservation, to build conservation awareness, and as a restoration incentive

    · Potential for culture and marketing of medical-grade corals for bone grafts

    · Cultured corals have multiple markets and can be used in reef restoration, so farmed corals are less vulnerable to fluctuations in market demand

    · No competition with other aquaculture or fisheries products

    · For eco-labelling purposes, corals are identified as of aquacultured origin by incorporation of monofilament line deep within colonies and by skeletal overgrowth onto bases

    · Establishing that corals are grown from cultured mother colonies, without negative impacts, and linked to conservation, will require third-party certification

    · Aquarium corals (live) must be kept in well-oxygenated seawater for air shipment, while curio corals (dead) have an indefinite storage life, and can be shipped by sea

    · For purposes of restoration or snorkelling trail enhancement, transport of corals is possible for several hours out of water, if regularly sprayed with water and shaded

  • Comparative advantages/disadvantages (risks) of producing the species in the Pacific:

    · Simple, low-cost technology and easy management. Suitable for small-scale operations and for self-employment of rural women and youth

    · Coral farming should best be introduced as part of a wider reef awareness and management context, and as an economic incentive for conservation

    · Coral culture should be done in the field; the culture of corals in greenhouses in developed countries not only produces tonnes of greenhouse gases but is a violation of indigenous property rights, as outlined in the UN Convention on Biodiversity

    · Risks to field culture: Stegastes 'farmer fish' can move onto culture tables and establish algal farms, killing the corals. If herbivorous fish are absent, algae can overgrow the cultured corals. Bleaching during warm water events can kill the corals, but can be prevented by covering the coral farm with shade cloth