Home on the Fish Range

But imagine a different model. What if, instead of being factory farmed like veal, fish could be let out to pasture like old-school cattle? They’d spread out, range freely, forage and fatten up in the wild. Then, weeks or months later, they could be called back in -- using the aquatic version of a cowbell -- and harvested. "Call and catch," as Boaz Zion, an aquaculture engineer at the Volcani Institute in Israel, puts it. Although sea (or "acoustic") ranching is still very much in its infancy, Zion and his colleagues have conducted several field experiments that suggest it can work, and they’ve built what he calls "an automatic fishing machine" to prove it. "What we want to do," he says, "is turn huge coastal regions into grazing fields of fish." The concept builds on several established, if under-appreciated, facts about fish. For starters, fish can hear. They can distinguish between different audio tones or patterns, even -- in the case of koi carp -- between classical music and blues. Indeed, fish can be trained; they learn and remember. In the 1980s, research in Japan and Norway showed that if free-swimming fish (including salmon and red sea bream) listen to an acoustic signal while eating at a feeder, they soon are conditioned to associate the sound with food. Play back the sound and the animals come looking: call them Pavlov’s fish. However, the research was never developed into a way to condition young fish and ultimately harvest them, Zion says. His own studies, in contrast, have aimed to "close the circle."...more