There are so many fish in the ocean that if you took them out, important habitats and food sources for many creatures would be lost.

When ships sink, they add artificial structures to the seafloor that can quickly become diverse, ecologically important underwater communities.

Concrete structures can recreate the complex forms of reefs, offering refuge to wildlife.

Researchers are trying to restore long-spined sea urchins, which eat algae that could otherwise smother reef ecosystems and kill corals.

According to a new UN report, invasive species do more than US$423 billion in damage worldwide every year. Four articles explore examples, from mollusks to poisonous fish.

A new way to preserve coral, called "cryopreservation," opens a path to year-round sample collection, critical for managing ocean threats.

Reef corals grow vigorously in nutrient poor water – new research has found out why.

This may buy us time, but many reefs are still doomed without serious action on climate change.

Ocean temperatures have hit record highs off the Florida Keys. Scientists and volunteer divers are racing to save these valuable creatures.