Small-scale fisheries supply many people with food. Almost all of those in this trade rely on gillnets (刺网) to trap fish. But gillnets trap other things, for example, endangered animals such as turtles; dangerous ones, such as Humboldt squid; and ones that are both endangered and dangerous, such as several types of sharks. Everyone involved would be better off if this did not happen.
Building on studies done both by himself and by others, to try to avoid the accidental netting of turtles, Jesse Senko, a marine-conservation biologist at Arizona State University, has been investigating the idea of fitting LEDs to nets to avoid netting other unwanted by-catch (误捕的鱼) without discouraging target animals. And, as he reports in Current Biology, it seems to work.
Dr. Senko and his team set up an experiment in the Gulf of Ulloa, in Mexico, in which they cooperated with local fishermen to employ over 10,000 meters of nets that had had nets battery-powered waterproof green LEDs fixed onto them every ten meters. Half of these lights were lit. The other half were left unlit, as controls. Each lit net was paired with an unlit one, and the two were used alongside one another at major fishing locations. The fishers’ target fish were large groupers (石斑鱼). Dr. Senko was interested both in what else got caught and whether the lights decreased catches of the target species.
On the latter point, to his relief, they did not. On the former, the lit net s caught 95% fewer kilograms of shark-related species. In particular, several threatened species turned up less often in the lit than the unlit nets.
The advantage from the point of view of fishermen was that they needed to spend a lot less time clearing these dangerous by-catches from their nets. And, crucially, the LEDs concerned are cheap, hard-wearing, and easy to fix. There are also plans to make them solar powered, for easy recharging. Here, then, is an environmental-protection idea from which everyone wins.
【小题1】What is the problem with gillnets?| A．They are costly to maintain. | B．They trap unwanted by-catches. |
| C．They discourage target catches. | D．They only trap dangerous species. |
| A．The principle of the experiment. | B．The results of the experiment. |
| C．The purpose of the experiment | D．The process of the experiment. |
| A．Fixing LEDs to gillnets is a win-win idea. |
| B．Fishermen benefit the most from the idea. |
| C．The Lit-net catches more threatened species. |
| D．The LED-net just catches less target species. |
| A．Critical. | B．Unclear. | C．Hopeful. | D．Doubtful. |
