At the time of this assessment there was only one U.S. farm for Yellowtail, raising 500-700 tons per years of Yellowtail in six sea station net pens (KBWF, 2008). Yellowtail escapes from net pens were a concern during the initial stage of operation, but farming technology has since improved reducing the frequency of escapes. A score of 1 was awarded because some Yellowtail escapes still occur.

NOAA, through the National Marine Aquaculture Initiative, encourages farming of marine finfish in near shore, open water, and terrestrial environments (NOAA, 2007). While funding is directed towards finding more sustainable farming methods, government policy does encourage expansion of high-impact net pens and cages (NOAA, 2007).

Species are raised at fairly low stocking densities of <30 kg per cubic meter (KBWF, 2008). Due to the low density of sites geographically and the relatively high current at the farm site (up to 2 knots) farm operations have had a minimal impact on water quality and benthic flora and fauna (Sarver, 2008).

Currently, farming operations for yellowtail in Hawaii must undergo a comprehensive permitting process, including securing the following permits: a National Pollutant Discharge Elimination System (NPDES) Permit, a U.S. Department of the Army Permit, a Conservation District Use Application, a DOH Solid Waste Permit, and an Aquaculture License (KBWF, 2008).

U.S. Farmed Yellowtail is currently fed a diet around 20% fish meal and fish oil (Sims, 2008, personal communication). The majority of fish meal and oil is from targeted reduction fisheries, while a small amount is trimmings from the British Columbia hake fishery (Sims 2008, personal communication).

NOAA, through the National Marine Aquaculture Initiative, encourages farming of carnivorous marine finfish in near shore, open water and terrestrial environments (NOAA, 2007). While grants are issued for research into alternative protein sources, encouraging farming of carnivorous finfish currently is highly dependent on fishmeal and oil.

The majority of fish meal and oil is from the Peruvian anchovy fishery, a species that is abundant, grows quickly and has low vulnerability to fishing (Fishbase 2008).

Both NOAA, through the National Marine Aquaculture Initiative grants program, and farmers of U.S. yellowtail are actively working to reduce the amount of fish content in feeds through grants for alternative proteins for feeds and feed trials (NOAA, 2007; Sims, 2008 personal communication).

The 'wet-fish-in:wet-fish-out' ratio for U.S farmed yellowtail has improved recently and is now approximately 1.0 (Sims, 2008, personal communication).

Effluent is not treated before discharge (KBWF, 2008).

Nutrient levels, measured using total organic carbon, around the farm vary seasonally, being slightly higher in fall when ocean currents are weaker (Sarver, 2008). By winter, nutrient levels are low and similar to sites away from the farm. Benthic surveys around the farm show no to very little impact to the benthic community (Sarver, 2008). Because current farming operations cause no damage or negative impact to the local environment, no points were deducted.

Currently farming operations for Yellowtail in the U.S. do not use feed sensors or floating feeds, however most feedings are observed by divers and cameras to avoid overfeeding. Excess feed is said to be consumed by wild fish around the cages (KBWF, 2008). No points were deducted.

Current U.S. Yellowtail farming operations use no prophylactic antibiotics. Florfenicol has been used several times to treat a specific bacterial infection under the supervisions of the US Fish and Wildlife Serve and veterinarians from the University of California, Davis (Sims, 2008, personal communication).

U.S. Yellowtail farmers must conduct regular water quality monitoring to fulfill the EPA's National Pollutant Discharge Elimination System (NPDES) Permit (KBWF, 2008). Additionally, currently benthic flora and fauna is sampled quarterly to monitor impacts (Sarver, 2008).

Escapes do occur, but Yellowtail is native to Hawaii (KBWF, 2008). At the beginning of farming operations tens of thousands of fish escaped (Sims, 2008, personal communication). Many small fish floated to the surface and were consumed by predators. Larger fish (3-4 kg), however, likely mixed with wild populations (Sims, 2008, personal communication). While escapes in farms have decreased with the use of Sea Station net pens, in December 2007, 1,500 fish escaped from Kona Blue's farm into surrounding waters when a diver failed to lock the bottom of the cage. Kona Blue is implementing procedures to ensure that this does not happen in the future (Honolulu Observer, 2008).

While there is high predation of escapees by trevally, seals, dolphins and sharks, the species is native to the area (KBWF, 2008). While the impacts and survival rates of escapees are unknown, it is likely that escapees, if not predated, would survive in the wild (Sims, 2008, personal communication).

Current farming operations do not selectively breed broodstock (KBWF, 2008). Also, broodstock are used for less than three generations (KBWF, 2008), thus there is little or no genetic difference between farmed and wild yellowtail. However, farmers are currently developing a selective breeding program to develop faster growing and more robust strains (KBWF, 2008). If these fish escape, they would likely breed with wild fish possibly altering the genetic make-up of wild populations. The farming operation will not begin culturing selected strains until net pen technology improves preventing fish escapes (KBWF, 2008), thus no points were subtracted.

Both foreign farmed and wild Yellowtail are very susceptible to viral infections, ciguatera and parasites (Hirayama et al., 2007; Perez-Arellano et al., 2005; KBWF, 2008). While low stocking densities are used in the U.S. and disease transfer may be less likely than in more high density operations in Japan and Australia, it is fair to assume that disease and parasite transmission are possible (KBWF, 2008).

Additionally, there is concern with similar farming operations in Australia that deformities in farmed Yellowtail caused by viral infections and insufficient feeding of juveniles may compromise the health of wild populations (Department of Fisheries, Western Australia, 2008). It is reasonable to assume that this would also be a possibility in U.S. waters.

Current farming operations use either wild, first or second generation broodstock, so farmed fish are at most three generations removed from wild populations (KBWF, 2008). Current farming operations, therefore, are unlikely to compromise the genetic integrity of wild populations.

Indigences of disease outbreaks in existing farming operations is low and occasional treatment of cages with hydrogen peroxide prevents against outbreaks of parasites (Sims, 2008, personal communication).

Current operations are located about 0.5 miles from shore, with cages located in waters 200 ft deep (Sims, 2008, personal communication). The substrate under the farm is sand and thus not as high-risk as other habitats such as coral reefs (Sarver, 2008).

Existing farming operations do not employ any predator deterrents (Sims, 2008, personal communication).

About 50 wild Yellowtail are harvested annually from healthy wild populations and used as broodstock. Seed comes from these wild broodstock and does not deplete the wild population (KBWF, 2008).