Sharks have long been wrongly feared as merciless killers of the sea. In fact, they are highly developed predators whose numbers are declining at a startling rate. Some sharks hatch eggs inside their bodies then give birth to live young. They thrive right at the water's edge, some even extending their root system into the sea. In addition, they prevent a great deal of coastal erosion.
Mangroves generally grow in areas where salt and fresh water mix.