To obtain shellfish, it’s often required dredging the sea floor. That’s a particularly nasty proposition, because it destroys reefs harboring complex ecosystems. And at the same time, it’s not particularly energy-efficient, and the damage done tends to also damage the shellfish recovered. However, a new type of non-invasive dredge is changing that (at least for scallops):

However, in one case—scallop trawling—Cliff Goudey of the Massachusetts Institute of Technology reckons he has a solution. He and his team have designed a dredge that can dislodge scallops without touching the seafloor. The dredge has several hemispheric scoops in place of the toothed bar. As it is pulled along, the scoops direct water downward. That creates a series of gentle jets that can shuffle the scallops from their resting places—but the streams of water are not powerful enough to damage the benthic zone’s long-term tenants. And the scoops swivel out of the way if they encounter anything solid, so the dredge does not destroy such protuberances. Best of all, from the fisherman’s point of view, it takes less effort to float a dredge on water jets than it does to drag it across the uneven surface of the seabed. That makes Dr Goudey’s new device a more fuel-efficient way to fish than the traditional method. Having assessed a prototype both in a laboratory tank and in the sea off the coast of Massachusetts, Dr Goudey was recently invited by the University of Wales to test his invention against a traditional dredge. New and old designs were dropped from the stern of a trawler and towed across the seabed off the Isle of Man. They each caught the same number of scallops. The new dredge, though, damaged the catch much less than the traditional one.

Most of what humans do is considered damage to the environment, at least by the strongest of environmentalists. And unfortunately, with the old dredging technique, they have somewhat of a point. There was very little way to capture the externality of damage done to the environment. So the environmentalists resort to their only tactic: ban it immediately.

But look at what happens when the market is able to innovate? They find a better way of doing it. It catches the same number of scallops, so it’s just as effective. It uses less energy, so it makes more money. And even better, it causes less damage to the scallops, so they can likely be sold for a higher price (earning more money). So fishermen make more money, the environment is not damaged, and consumers get higher-quality scallops. We’ve all become richer– due to capitalism.