Science: Bubbles for Fish

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The Bureau of Commercial Fisheries was planning a dirty scientific trick to play on schools of herring and menhaden off the Maine coast last week. At Boothbay Harbor, Me., the 139-ft. "pogy" (menhaden) boat Rappahannock is fitted with a 52-h.p. compressor that delivers 196 cu. ft. of air at the pressure of 80 lbs. per sq. in. The idea is to shoot the air through perforated tubes sunk in the water near schools of fish. Curtains of bubbles rising from the perforations look to the fish like an impassable barrier and shoo them toward the Rappahannock.

When the bubble-bothered fish approach the Rappahannock, they will lose control of their swimming muscles. Pulses of electric current shot into the water from electrodes will make their tails wiggle rhythmically, steering them helplessly toward the ship. When they get close enough, the intake current of a powerful fish pump will suck them aboard. If this system works as the bureau hopes, it will revolutionize the business of harvesting fish that travel in dense schools.