Salmon, carp, trout, and tilapia that grow up to six times more rapidly than those in the wild are being developed for commercial production in America and China. If the U.S. Food and Drug Administration
approves its proposal, Massachusetts-based Aqua Bounty Farms could begin marketing transgenic salmon eggs to fish farmers as early as 2002. Other scientists are using genetic engineering to create fish with increased cold tolerance and disease resistance, or even the ability to detect pollution.
The Promise: Fast-growing fish could replenish fisheries without depleting natural stocks and boost efforts to end world hunger. Researchers in Singapore are trying to develop fluorescent zebra fish (altered with jellyfish proteins) that would detect pollution by turning different colors depending on what substances--including hormones and heavy metals--are in the water.
The Peril: As with hatchery fish, genetically engineered fish that are accidentally released into the environment could disrupt natural ecosystems. (Accidental release is common because of storms and damaged holding pens. No law requires breeders of transgenic fish to keep them from escaping into local waters.) Fast-growing transgenic fish might out-compete native species for food, for example, yet produce young that are ill-equipped to survive. Aqua Bounty plans to make its fish infertile, but current sterility methods are not entirely effective. Even if they were, this would create other problems: As with “Terminator” technology in plants, farmers would not be able to breed their own fish, making them reliant on suppliers of transgenic eggs.