Coral reefs are some of the most endangered ecosystems on the planet that are home to beautiful wildlife and provide food to many people living on the coast. So how do you protect the reefs without cutting off communities from their food source? Instead of creating one big marine protected area to conserve coral reefs, one idea is to protect a series of smaller reef areas. A series of protected reef areas keeps any one reef from being off-limits to fishermen and, if they're close enough together, should function as one large reef ecologically. This idea—that the smaller safe havens need to be close enough together that they are connected—is called "reef connectivity." If the small reefs are connected, fish can swim between them, making sure that fish populations stay large and healthy. Learn about why this is so important and how scientists are using genetics to make sure reefs are connected in this video by marine biologist Joshua Drew.