There are a number of reasons that many people are opposed to fish farming. Among other things, they claim that the caged fish release too much concentrated waste into the surrounding waters, too many antibiotics and anti-algal chemicals are used, the ecological balance is upset when non-native fish escape from their pens, and strain is put on populations of local fish that are captured for use in feed for carnivorous farmed fish. Unfortunately, wild-fish-capturing methods such as drift net fishing and bottom trawling have big problems of their own. A new system that involves raising fish in mesh spheres that float in the open ocean, however, is claimed to sidestep many of the drawbacks of traditional marine aquaculture. The Velella Research Project is pioneering the technology.
The project is being carried out by marine biologists from Kampachi Farms (formerly Kona Blue Water Farms), an aquaculture company based out of Hawaii's Big Island. They are experimenting with raising hatchery-born Almaco jack fingerlings in a 22-foot (6.7-meter) diameter Aquapod, a floating spherical brass mesh fish pen. Instead of being moored in one place, the pod is drifting in eddies that carry it 3 to 150 miles (4.8 to 241.4 km) off the island's west coast, in waters up to 12,000 feet (3,657.6 meters) deep.
The Aquapod is tethered to a tender vessel, which houses marine biologists who feed and monitor the fish. The boat's engine is occasionally run to make course corrections, although it mostly just drifts with the pod. Its location is tracked at the project's land-based headquarters using GPS.
Because the pod is drifting in the open ocean, with the current flowing through it, the fish waste is continuously carried off and dispersed. The brass mesh resists biofouling, so anti-algal chemicals aren't needed, and the Almaco jack (also known as Kampachi) are native to the region. Also, much of the fish meal and fish oil in their feed has been replaced with sustainable agricultural proteins such as soy.
Velella is not entirely unopposed, however. Hawaiian environmental group KAHEA has raised concerns that the National Marine Fisheries Service was premature in issuing a permit to the project, having not sufficiently investigated its possible ecological impact on the region. There are also worries that even if the one Aquapod causes no problems, future multiple pods dispersed in one area could.
Kampachi Farms co-CEO Neil Anthony Sims countered that drift pen technology has virtually no environmental impact on the underlying seafloor, surrounding water quality or wild fish outside the Aquapod, and that the test fish are healthy and growing well.
The word Velella, incidentally, is the name of a family of marine creatures that float on the surface of the open ocean.
More information on the project is available in the video below.