Ocean Secrets: What Science Has Yet to Discover About the Sea

In the vast and immense bodies of water covering our planet, where light is only close to the surface and darkness and mystery are found in the deep, many creatures rely on size, speed and strength to survive. But some have evolved another trait, perhaps the most powerful of them all, family. Somewhere in the North Atlantic Ocean, these giants are sleeping. Female sperm whales are highly social. They live in family groups called pods and work together to raise their young, while adult males travel alone or move from pod to pod. Like all mammals, whales need to breathe air, so they sleep just below the surface and come up for air in between short naps. Sperm whales spend just seven percent of their time asleep, less than any other mammal on earth. So it's rare to witness a family slowly waking up after a deep sleep. The females in this close-knit family group will stay together for 10 or more years. They share knowledge, sounds and hunting skills with one another. Learning from each other helps them develop a deep bond and sense of belonging, critical for the survival of their family and their species. Sperm whales live in an environment totally different from ours. They see the world through sound. And though it may sound quiet to us, the ocean is a noisy place. And sperm whales are the loudest animals found anywhere on earth. They use a system of clicking sounds to communicate and strengthen the bonds between females. Their clicks are so powerful, they can transmit messages over hundreds of miles, even across vast oceans. Usually though, the clicks are used like a kind of sonar to find food. A sperm whale spends most of its life at the depths of over 3,000 feet, hunting for squid in total darkness. About 60 million years ago, a hoofed wolf-like mammal traded its terrestrial lifestyle for an aquatic one. Over time, it evolved into many different forms, including all 80 species of whales, dolphins and porpoises we know today. In the warm waters around the Bahamas, a pod of spotted dolphins is playing and bonding. Calves don't have spots like their parents, so it's easy to mistake them for small bottlenose dolphins. Their spotted patterns begin to develop after their first birthday. Spotted dolphins are extremely social animals. To communicate with each other, they blow bubbles through their blowholes and use whistles, clicking and other sounds. Dolphin calves are born with very few survival skills, so they rely on their mothers to teach them almost everything. The bond they share is the strongest relationship these dolphins will have in their lifetimes. Pregnant females begin teaching their calves even before they're born. In the weeks before and after they give birth, they repeat their own signature sounds over and over. This teaches the newborn calf how to recognize its mother's voice so it can bond and imprint to her. The pod is highly protective over pregnant females, and during this time, they help by quieting down. Once a calf is born, the real education begins. Moms teach their calves how to breathe, swim, and of course, have fun. With so much to do, new moms get little sleep in the first few months. They nurse their young three times longer than any other large whale, and with help from the rest of the pod, mothers take care of their calves for up to five years. With so much maternal care and support from the group, spotted calves are given everything they need to succeed in life. Unlike the spotted dolphins that live in large pods, there are others characterized by having a smaller family nucleus. In the coastal zone of the South Pacific, where the waves crash against the cliff, another family unit is going about their day. At just 10 pounds and three feet long, when full grown, marine otters are the smallest marine mammals in the world. These marine otter pups aren't old enough to hunt for themselves yet, so they spend their days doing what otter pups do best, playing, waiting for mom, and being cute. Soon, these pups will have to go off on their own, but for now, there's nothing more important to them than their mother, and nothing she wants more than to spoil her pups. Otters are intelligent and social animals, so there's always time to bond and play. With a very fast metabolism, otters need a near constant supply of calories to keep warm. With little body fat, they must hunt several times a day to stay alive in these cold South Pacific waters. To be a good otter mom, you must be an excellent hunter, so you can provide for your pups. To hunt in this environment requires skill, experience, and patience. Fortunately, this otter mom knows exactly where to look to find tasty prey like shrimp and fish. Otters need to consume 30% of their body weight every day, and with two pups at home waiting for dinner, she can't go home empty-handed. After their afternoon playtime, the pups are hungry. They're in luck. Mom has brought back a delicious crab. These young otters eat just as much as an adult, so she must continue to provide food almost around the clock. She knows this will not be enough and heads out for the second course. Mom must eat too, and while the pups are off playing on the rocks, she catches a shrimp and enjoys a little peace and quiet. Winding along the Pacific coast of South America, the humble current emerges from the deep. It brings with it nutrients that form the base of the entire food web. But animals depend on more than just food for survival. Like us, they need shelter to protect themselves and raise their young. A colony of South American sea lions has gathered on this rocky shelf, like they do every year for a very special occasion. They're about to bring new life into the world. During pupping, a female will call to her pup, and the pup should instinctively reply. But something is wrong. Pups are usually