What is the main idea of this paragraph?

Most people think that gorillas are mean, but actually they are shy. It seems that such a huge animal with very large teeth would be aggressive. Hollywood movies help convey this image of the scary, ferocious gorilla. In fact, gorillas only attack if they are provoked.

This author believes that:

The deep-sea divers pursuing profit must carefully research their sites to make sure it is legal to take artifacts from the location. They must also take measures to preserve the artifacts so that they don't corrode and lose value once they are recovered. For these deep-sea divers, the measure of their success is the dollar value of the treasure they find.

what is the central idea of this paragraph?

The Unusual Venus Flytrap

The Venus Flytrap is an unusual plant with many admirers. This carnivore plant grow in the bogs of North America. With read lines lobes that resemble a mouth, the Venus Flytrap looks more like a creature than a plant. It uses these lobes to capture and eat insects and can even digest small frogs! The lobes have small trigger that causes the plant to clamp in a single second when unsuspecting prey come too close. Finger-like extensions called cilia intertwine to keep the lobes shut tight. It is that trapping action that people find that fascinating.

what are the steps to determine the central idea in a nonfiction text?