Almost half of the world’s seafood now comes from fish farms, which can cause significant environmental harm if not responsibly managed.
Because many fish are confined to a small area, aquaculture can lead to high levels of pollution and outbreaks of diseases. Sometimes the farmed fish escape, which can hurt wild fish populations and the local ecosystem. Aquaculture can also lead to overfishing since carnivorous fish, like salmon and tuna, are fed large amounts of fishmeal made from prey fish like anchovies or herrings.
The Velella Project is an experiment off the coast of Hawaii that is trying to address some of the problems associated with aquaculture. Instead of enclosing fish in stationary nets or tanks like traditional farming methods, a specially-designed spherical pen, called the Aquapod, drifts through the water containing 2,000 hatchery born fish.
In the Aquapod, wastes are less concentrated since the pen is free-floating. And while the Aquapod was designed to reduce escape, the choice of fish can also help limit the potential damage escapees might cause. The pen contains Almaco jacks (related to yellowtail), which are native to the area and tend to school with other fish – meaning that if any do escape, they would probably just hang out near the pen. While Almaco jacks usually eat small baitfish, fish in the Aquapod are fed a protein diet high in soy. While using soy to feed fish raises some questions since it isn’t naturally found in the ocean, the project designers hope that the ratio of fish produced to food required is more sustainable.
Although offshore aquaculture may be one way to limit the harmful effects of fish farming, the Velella Project is still being tested and may not be the perfect solution. One obstacle is maintaining and tracking the pens, which requires ships and fuel. Another is the lack of existing regulations specific to open water aquaculture.
While more progress is still needed, it’s encouraging to see new approaches that could reduce the pollution, risk of escape, and pressure on wild fisheries caused by traditional aquaculture.
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