Two notable ways than setting fishing limits can help protect fish species:
Preservation of fish - this prevents extinction, and at the same time helps other species of fish catch their prey. Thus, making the food chain stable.
Preserves the nature of underwater - fishes tend to take care of their underwater world, and preserving them helps maintain the appearance under the oceans and sea.
Whatever fossil is at the lowest layer is the oldest cuz the old fossils lived along time ago and when they died the fossils were buried.
