Abalone Culture in Cages
Abalone culture is not a complicated project. Proper site selection and feeding regimes are the major requirements to be considered, The availability of market and stable price is more attractive to would be growers.
Site Selection – Abalone farming is very easy which does not require complicated techniques and facilities. The most baste requirement is the selection of good site with following features:
- a) Protected from very strong waves and current,
- b) Free from pollution and influx of fresh water run off,
- c) Clear water with sandy or rocky bottom,
- d) Water depth of at least four meters at low tide or at a depth that provide an allowance of one meter distance between net bottom and seabed,
- e) Near from the source of seaweeds (Gracilaria sp.),
- f) Accessibility to transportation and communication,
- g) Very cooperative socio-economic situation and,
- h) Effective water circulation
Materials – The Initial capitalization for establishing an abalone farm is extensive as compared to other marine species. The cage module is very much affordable even by the small-scale fish farmer with minimal capitalization. The cage is made up of empty 20-liter capacity black-plastic containers enclosed with various types of netting to prevent escape of the stock or entrance of unwanted species into the cage.
Removing one of the walls opens the container after which two inches diameter holes were punched around to facilitate effective water circulation. A bamboo raft is used to suspend the cages under water. The following are the bill of materials for the single cage, and the cage module.
The cage module is expected to be in use for the minimum duration of 3 to 4 years with minimal maintenance cost. The main component of the cage which is the plastic carbouy may be used for 5 to 10 years provided proper care is observe during the operation. Therefore the cage module will be able to sustain production of three to four cropping per year for three to four years span,
Operation of modules observes the 1-2-4 modular stock and transfer scheme. An initial of 600 abalone juveniles of 1 cm shell length is initially stock in the nursery cage. After 2 months, the stock is then about 3 to 3.5 cm shell lengths were thinned by transferring into the transition cage at a stocking rate of 300 juveniles per cage. The third phase in the thinning and transferring the stock into the grow-out cages at density of 150 abalones per cage, this is done after two to three months of culture at the transition cages.
Farm Maintenance and Management
Proper maintenance of the cage farm structures insures its full lifespan performance. Such activities includes the following:
- a. Daily check up of cage damage and dogs. Fouling organisms should be removed immediately before it hampers water circulations and causes loss of stocks,
- b. Floats and anchors should be checked at least once a week to check if it is in proper position and free from debris that may lower the efficiency of the structure.