Northern fur seals congregate on the Pribilof Islands in the central Bering Sea only in summer and fall. During the winter months, where do the seals go, and what do they eat? To understand the seals' migration pattern and food resources, researchers from NOAA use satellites to track migrating fur seals throughout the year. The resulting data reveal the wandering route that each individual seal takes as it travels alone for about eight months—with some traveling up to 6,000 miles!

But the fur seal population is declining, and fewer and fewer young seals are returning to the Pribilof Islands each year. By tracking and studying the seals along their migration route, scientists are hoping to find the answers that will help ensure the seals' survival.

Attaching a tracking device on a white shark, one of the most fearsome marine predators, doesn't just provide a thrilling rush of excitement and adventure! This tracking technology provides researchers with valuable data on shark behavior—such as their migration pattern and what they eat.

How do robots and flying drones help scientists study the ocean? From observing and surveying marine life on rugged coastlines to mapping remote seafloor habitats, unmanned robots safely perform tasks that would be too challenging, if not impossible, for humans to do. In this video, explore some of the innovative technologies that are being used to help study—and protect—our marine ecosystems.

A well-placed camera or acoustic recording tag on a humpback whale allows researchers to track its underwater movements and observe its behavior. The data gathered from these scientific instruments give national marine sanctuary managers important information that can be used to save whales from getting tangled in commercial fishing gear and from colliding with ships.

How do scientists find out what food is available to marine mammals and seabirds? They use a system of special nets called a "tucker trawl." The nets open and close at different depths, allowing researchers to sample zooplankton and other small marine organisms that serve as food sources throughout the water column. Watch as researchers demonstrate how a tucker trawl works.

Information gathered from tucker trawl sampling is part of an effort by researchers to better understand ocean processes impacted by natural and human-caused changes. By tracking key seabird and marine mammal forage species, national marine sanctuaries can apply the information to protect wildlife; for example, they may redirect large ships away from important feeding areas.

Manta rays feed on plankton and fish eggs by gliding through the water with their mouths wide open. As they glide, they gulp in water and food particles, which then filter through their gills. But how do mantas sift out enough particles from filter feeding to make a meal? And why don't the particles clog up the filters, similar to how pasta gets "caught" when drained through a colander?

These are some questions that marine biologist and biomechanist Dr. Misty Paig-Tran has been studying. From preserved manta specimens, Dr. Paig-Tran was able to discover differences in filtering mechanisms among different species. Building and testing 3-D models of the filters in a flow tank reveals how the structure of the filters efficiently keep food particles moving back toward the manta's throat, rather than collecting on the filter's surface, and thereby providing a sufficient meal for a manta ray.

Why are Steller sea lion populations continuing to decline on the western part of their range in the northern Pacific Ocean? In this video, researchers travel to the Aleutian Islands in search for answers, using technologies from air and sea to gather data on Steller sea lion population trends. The more scientists understand about what's going on with sea lion populations, the better they will be able to help protect the species and the habitat in which they live.

There are over 450 species of sharks! With sizes that range from as big as a school bus to as small as your hand, sharks have roamed the ocean for over 400 million years. Sharks are a diverse group; however, most share a common role in marine ecosystems—they are apex predators at the top of the food chain. This means that sharks have no natural predators of their own. They feed on prey at lower levels in the food chain, including fish that are weak, old, and unhealthy. This helps stop disease from spreading through fish populations—and is just one way that sharks keep marine ecosystems healthy.

But many shark populations are rapidly shrinking. Reasons for this decline include both natural factors (slow growth rate, small number of offspring) and human causes (overfishing, bycatch, shark finning). However, growing global awareness about the vulnerability of shark species and international cooperation are helping protect these key predators needed for a healthy ocean.

Sometimes, fishermen catch more in their nets than they intend to. Fish and other ocean animals that get unintentionally caught in fishing gear are called "bycatch." In this video, see how scientists, gear specialists, and fishermen are working together and using what they know about fish behavior to design fishing nets, or trawls, that are "selective" in what they catch.

Every year, hundreds of thousands of whales and other marine mammals die when they become entangled in fishing gear or marine debris and drown. In this video, get an up-close look as highly trained rescuers risk their lives to swiftly but carefully cut away fishing lines from an entangled 40-ton humpback whale.

How can a restaurant help the ocean? When you go out to eat, it can be hard to choose when it comes to seafood. What type of seafood is safer to eat? Which types have been sustainably harvested? Seafood restaurant owner Laura Anderson wants to make that choice easier for her customers. In this video, explore how Anderson works hard to find and serve seafood from local, well-managed, sustainable fisheries—meaning the fisheries have low unintended bycatch, create minimal negative impacts to habitats, and take care to not overfish.

With their massive bodies and streamlined forms, gray whales are one of nature's most graceful giants, gliding gently and effortlessly through the water. Every year, they embark on the longest migration of any mammal—12,000 miles from the icy waters of the Arctic to the warm lagoons of Baja, Mexico, and then back again.

In the 1700s and 1800s, gray whales were hunted to near extinction. Thanks to protection from an international treaty and the Endangered Species Act, the eastern Pacific gray whale population has recovered to a sustainable level. Today, a sizeable population of gray whales inhabit the open ocean and continue their impressive annual migration along the coast of North America.

Steller sea lions, also called northern sea lions, are the largest species of sea lions. They inhabit the coastal waters of the northern Pacific Ocean, where they seem to dance and fly as they swim gracefully through the water. Observing such agile swimmers can help scientists better understand form, function, and adaptations in a watery environment and perhaps inspire new technologies for the human world.

Blue whales, which can grow to about 90 feet (longer than two school buses end to end), are the largest animals by weight known to have ever lived on Earth. But how does something get, and stay, this big? That's one of the questions that Jeremy Goldbogen, a researcher at Cascadia Research Collective, is trying to answer. Supporting a body that size requires a lot of food, and a lot of eating. That's why Goldbogen is studying the dining habits of blue whales.

Blue whales are a type of baleen whale: instead of teeth, they have strong, flexible plates of baleen in their mouths made of the same protein as your fingernails. The plates hang from the whale's upper jaw, much like the teeth of a comb. Blue whales feed on krill, which are shrimplike crustaceans. The whales take in water and then use their tongues to push the water through their baleen. The baleen acts like a strainer and traps the krill. Goldbogen and his colleagues collect data through cameras that they place on the backs of whales off the coast of California. The video from these cameras tells researchers that blue whales feed continuously, taking in krill by the millions with each gulp—a gulp that is big enough to drink an entire swimming pool—and employ a maneuver dubbed the "blue whale barrel roll." This move, which is a bit like riding a roller coaster in the ocean, positions the whale's mouth in a way to get the most efficient gulps.

Harbor seals and northern fur seals belong to the pinniped family. "Pinniped" means fin or flipper-footed. Although these two types of seals share some similarities in structure—streamlined bodies, rounded heads, small tails, and flippered limbs—they have distinct differences, including their ears, coat thickness, and the shape and function of their front and rear flippers. The differences in the structure of their fins lead to a difference in the way they move, too. In this video, you can observe the difference in the way that harbor seals and northern fur seals move on land and in water.