Question

read the passage. saving sea turtles small - scale fishing performed with nets is one of the most common fishing methods used around the world. one of the unfortunate side effects of this method is that sea turtles, which are considered threatened, get caught in the nets along with the fish. conservation biologists at the university of exeter in england recently devised a way to prevent these sea turtle deaths, which they tested at a fishery in northern peru. they found that attaching green led lights to the nets warned the turtles away, possibly because the lights made the nets more visible. the number of sea turtle deaths was reduced, but the number of fish caught seemed to remain the same. what is the main, or central, idea of the passage? conservation biologists are researching ways to save the threatened sea turtle population. to prevent turtles from becoming caught in fishing nets, conservation biologists attached led lights to the nets. one problem with small - catch fishing is that sea turtles get caught along with fish.

Explanation:

The passage first mentions the problem of sea turtles getting caught in fishing nets (small - scale fishing side - effect). Then it focuses on the solution: conservation biologists attached green LED lights to the nets (tested in Peru), which warned turtles away, reduced turtle deaths, and didn't affect fish catch. The first option is too general as it just says "researching ways" without specifying the method. The third option only mentions the problem. The second option includes both the problem (turtles in nets) and the solution (attaching LED lights), which is the main idea.

Answer:

To prevent turtles from becoming caught in fishing nets, conservation biologists attached LED lights to the nets.