Diversifying Hawai'i Aquaculture with Clam and Oyster Culture

Diversifying Hawai'i Aquaculture with Clam and Oyster Culture

Summary

This project was designed to resolve issues related to the dependence of novice bivalve farmers on purchasing large oyster seed rather than buying less expensive, locally available, eyed oyster larvae and setting these at their farms. Large, set oyster seed is expensive and is shipped to Hawaii, largely from Washington or Oregon. 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.

Although this work began promptly and showed early signs of success, significant setbacks were experienced due to: 1) two tsunamis (2010 and 2011), one of which damaged the farm sites in early 2011; 2) health issues among project personnel; and 3) early FLUPSY designs proved impractical due to electrical and cost elements, which were originally not anticipated. Th project is now back on track.

Objectives/Performance Targets

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).

Training sessions were successfully held on O’ahu and Moloka’i in November and December 2010 for new and prospective oyster farmers. Eight students at UHH have also been trained in setting and nursery methods, as they were expected to act as research assistants during the project. These students come to UHH from their home islands of O’ahu and Moloka’i. It was originally planned that they would return to their home islands and spend part of their summers working on the FLUPSY set-up and early testing.

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).

Initial attempts to use conventional FLUPSY designs failed due to unforeseen circumstances. In one case, the lessor of the farm property decided to demolish and then renovate the training center, which included the electrical and water connections that were to be used by the project. The new facility, which took over one year to build, is a significant improvement and now provides a more usable base for the farming operations, but the construction impeded progress with the FLUPSY installation.

The oyster farm on Moloka’i also suffered significant damage in the tsunami of 2011. Approximately 80% of the wall of the traditional Hawaiian fishpond where the farm was sited was destroyed. This is a historical site and, apart from the tragedy represented by destruction of the wall, this also led to the inability of the operators to control water levels, exclude large predators and increased wave action in the farm area. The wall has been rebuilt with completion in November 2011. Work can now resume at this site.

Initial attempts to design a FLUPSY using conventional designs also failed due to inadequate water levels, changes in water quality and the high costs of providing electrical power to the FLUPSY. It became apparent that the only feasible power source for the FLUPSY would need to be photovoltaic.

To date several designs have been made, and small prototypes have been made and tested at UHH. Currently, a final version is being assembled. The ability to set oyster seed and nurse them using the photovoltaic system will be tested in December 2011 and January 2012 at UHH. Pending the need for modification to the system, testing will then take place at the two oyster farms in early 2012. This will coincide with the availability of oyster larvae for setting when the UHH bivalve hatchery also resumes production in the spring of 2012.

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).

Pending completion of Objective 2.

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).

Pending completion of Objective 2 and resumption of operation of the UHH hatchery in the spring of 2012 to supply oyster larvae.

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).

Pending completion of Objective 2.

Objective 6: Grow-out in FLUPSY (Month 8-9) with monitoring of growth and survival.

Pending completion of Objective 2.

Objective 7: Transfer of spat to grow-out system in ponds. Training in shellfish grow-out methods. (Month 10).

Pending completion of Objective 2.

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.

Pending completion of Objective 2.

Accomplishments/Milestones

Initial training has been provided in oyster culture methods to farmers and students. Preliminary FLUPSY designs have been tested. A prototype, photovoltaic FLUPSY is now under construction, and we will begin testing in late December 2011.

Impacts and Contributions/Outcomes

The initial training in basic oyster biology and culture methods has been useful in preparing the farmers for the setting and nursery work, for which a good understanding of oyster biology and culture methods is necessary. The farmers are now actively culturing oyster in preparation for the new initiative related to classification of oyster growing areas and are also conducting research to resolve other pending oyster culture issues that are specific to the use of the Traditional Hawaiian Fish Ponds as culture sites. Other outcomes are pending further progress on testing and installing the FLUPSY system in the traditional Hawaiian Fishponds.

Collaborators: