World Aquaculture December 2019

20 DECEMBER 2019 • WORLD AQUACULTURE • WWW.WA S.ORG Technicians only needed to visit the farm site once a week to top up feed in the hopper and fuel the generator. Both of these Velella projects were also important in establishing precedent for permitting of aquaculture in federal waters (between 3 nm and 200 nm). A spin-off company – Forever Oceans – continues to refine the remote command-and-control technologies using innovative net pens at the site offshore fromKeauhou Bay. A very recent innovation is the planned development and operation of an offshore seaweed farm, “Blue Fields Offshore Macroalgae ( limu ) Demonstration Project” consisting of a submerged platform tethered in 120-ft deep water, 1.5 miles offshore of Keāhole Point near Kailua- Kona. Seaweeds will receive nutrients from deep seawater pumped to the platform. The culture of several native macroalgae species will be attempted to demonstrate the farming potential with the projected uses for human consumption, for fish feed and provision of biomass (Kampachi Farms 2019). Aquaponics is another form of aquaculture that has gained widespread popularity. There are four major farms and a plethora of small-scale operations, many of which are closer to hobby scale than commercial operations. Challenges faced by aquaponic operations are the high cost of energy and food safety requirements. Nonetheless, aquaponics offers a high degree of potential to increase local food security, provide family revenue and represents a system that can be used on sites where other systems such as ponds are not feasible. A recent study indicated that small-scale operations can be economically viable (Tokunaga et al. 2015). Land-based systems of various levels of intensity predominate at the HOST Park facility and include production of abalone, seaweed, marine fish and bivalves. Most of these utilize the deep ocean water provided by HOST Park from offshore pipes descending several thousand feet deep for animal and plant grow-out or temperature control. High-intensity land-based systems have potential in Hawaiʻi, particularly for rearing native marine fish, but these systems have not yet been fully explored. Pond aquaculture is also not as common in Hawaiʻi as it is in other regions, primarily due to the high cost of land and in some cases, the difficulty of building ponds on lava flats which cover extensive areas on Hawaiʻi Island. The latter is yet another reason for the interest in greenhouse agriculture and aquaponics. Traditional Hawaiian fishponds continue to be some of the best sites for aquaculture (Fig. 9), although their proponents continue to struggle with the cost and difficulty of obtaining permits for reconstruction and operation. Recent clarification and streamlining of the Federal and State permitting processes has eased this somewhat. Aquaculture in Hawaiian fishponds relied on the ability to capture juvenile and adult fish from the wild, a practice that continues at many ponds, but the most appropriate species, such as milkfish and mullet, are now less abundant in the wild and are not routinely produced in Hawaiʻi’s hatcheries on a regular basis. Researchers at OI have supplied mullet fingerlings to evaluate in cages within traditional fishponds on Oʻahu and Molokai over the last few years. The PACRC worked with several pond managers to test oysters and clams, which growwell in the fishponds, but water quality issues barred further trials except for a few ponds such as those at Moli`i (Oʻahu) and Keawanui (Molokai). Efforts continue to determine which combination of ancient and modern practices will work in the Hawaiian fishponds, as practitioners keep their eyes on the goal of perpetuating these cultural treasures as a thriving piece of the broader food system in Hawaiʻi. Education and Extension One of the important factors in the early largely successful efforts to establish viable commercial aquaculture in Hawaiʻi and the USAPI was the coordinated efforts of the State of Hawaiʻi, UH Sea Grant, NOAA and various USDA agencies to provide targeted funding for applied research and hands-on extension services to producers. Sea Grant and CTAHR, along with the ADP, sponsored a statewide extension network that provided expert services on every island. The Center for Tropical and Subtropical Aquaculture (CTSA), the region’s USDA Regional Aquaculture Center, has also played a key role in funding numerous research projects selected by industry members since 1986. Its long list of aquaculture publications is a wealth of information documenting progress with aquaculture and is invaluable FIGURE 8. The Aquapod sea cage from the Velella Beta-test showing the cage, divers and the hull of the attendant vessel. Autonomous or semi-autonomous sea cage designs offer new options for open-ocean mariculture. Photo: Rick Decker. FIGURE 9. Over 400 Hawaiian fishponds existed prior to Western contact. These ponds are only two of dozens which line the Molokai shore. The fishponds are prime aquaculture sites for many species. Photo: Andre Seale.