- Animals: shellfish
- Animal Production: housing
This project was designed to resolve issues related to the dependence of new bivalve farmers on purchasing large oyster seed rather than buying less expensive, locally available eyed oyster larvae and setting these at their farms. The ability to purchase less expensive larvae and set them, then use a floating upweller system (FLUPSY) will greatly enhance the ability of new farmers to reduce costs and control their own production. An improved understanding of the basics of oyster biology and culture methods is also essential to new oyster farmers. A functional and useful FLUPSY was designed and tested at two traditional Hawaiian pond sites that are among the first to culture oysters in Hawaii. The ability to use a solar powered FLUPSY will enhance farm efficiency and profitability, as electrical costs are high in Hawaii.
Hawaii has long been the only U.S. state where bivalve shellfish cannot be farmed due to the Department of Health’s (DOH) partial implementation of the State Shellfish Sanitation Plan. DOH has traditionally only implemented the portions of the Plan that relate to importation of shellfish, not the components related to classification of growing areas. In June 2012, DOH began full implementation of the Plan and began the water quality sampling required to classify shellfish growing areas. Hence this Western SARE-funded project came at a most fortuitous time and will contribute to the development of a Hawaiian shellfish industry.
Shellfish farmers have two options for obtaining stock for their farms. Stock or “seed” is one of the highest costs for shellfish farmers. They can buy “spat” (juvenile animals), which is a high cost-option. For example, 4 mm oyster spat cost around $10 per thousand ($10,000 per million) and most farms require several millions to stock their farms as some mortality occurs in the nursery process. The lowest cost option is to buy eyed-larvae and set it themselves. Eyed-larvae currently cost $150/million (2013). Even with some morality during the setting process, purchasing eyed-larvae and setting these on the farm is clearly the lowest cost option for farmers.
Hatcheries produce eye-larvae, which are advanced-stage larvae on the verge of being ready to go through metamorphosis and set on a substrate. These larvae can be shipped without water at a low cost to farmers to set in their remote areas. This process is called “remote setting.” Remote setting requires the farmer to have one of several possible setting systems to be feasible. Generally setting is done either in tanks or in downwelling systems. After setting, the small spat are then transferred to a Floating Upwelling System (FLUPSY) which constitutes a nursery system. The FLUPSY is one of the most efficient methods of raising small bivalve seed. Electrical power is required for this system as a pump is used to supply the spat with water and algae that is found naturally in the water.
A complicating factor is that most of the prospective oyster farmers in Hawaii do not have electrical power in their farming areas. The configurations of the ponds and surrounding sites, particularly the large extents of shallow water, inhibit use of conventional setting systems. Moreover, electrical costs are among the highest in the nation. Hence, if a FLUPSY is to be used in Hawaii, an alternative source of power is needed. The goal of this project was to design and test a solar-powered FLUPSY that would effective in the unique settings of the Hawaiian fish ponds.
Project objectives:div style="margin-left:1em;">
Objective 1: Pre-implementation meetings and planning for producers and aquaculture extension specialists, with training in basic shellfish culture also to be presented (Month 1).
Objective 2 : Procurement and shipping of materials to the two demonstration sites. Development of draft training materials to be used in training. Experienced oyster farmer to provide assistance in training and advise on design of systems (Month 2-3).
Objective 3: Field days on Moloka`i and O`ahu to build and install remote setting systems and floating upwelling systems (FLUPSY) with accompanying training. Experienced oyster farmer to provide assistance in training. (Month 4).
Objective 4: Larvae to be sent to Moloka`i and O`ahu for setting in remote setting system with training from aquaculture extension specialists (Month 5).
Objective 5: Spat previously set in remote setting systems on Moloka`i and O`ahu to be transferred to FLUPSY for nursery state with accompanying training (Month 6-7).
Objective 6: Grow-out in FLUPSY (Month 8-9) with monitoring of growth and survival.
Objective 7: Transfer of spat to grow-out system in ponds. Training in shellfish grow-out methods. (Month 10).
Objective 8: Grow-out in ponds with monitoring of growth and survival (Months 10-22). Revision and final printing of extension materials based on results.