Changing Seas

How do you count two fish, three fish or even a school of fish? In Dry Tortugas National Park, located 70 miles from Key West, Florida, a group of scientists have joined forces to conduct a massive fish census.

Bottlenose dolphins are a beloved Florida icon. But, recent studies show disturbing signs of immune system dysfunction and disease plaguing this charismatic mammal.

They are an ancient species of flowering plants that grow submerged in all of the world's oceans.

In the turquoise blue waters of the Florida Keys, a new attraction is drawing scuba divers from around the world: The USNS General Hoyt S.

In the waters of the western Atlantic and Caribbean, a voracious alien predator has taken hold.

In the emerging science of coral reef restoration, marine biologists and resource managers are discovering naturally occurring mechanisms that promote coral growth and restore ecological balance in these gardens of the sea.

The oceans are part of America's newest medical frontier.

Last year's catastrophic oil spill in the Gulf of Mexico may no longer make headline news, but the story is far from over.

Scientists studying the coastal Everglades have made some perplexing discoveries.

While Elkhorn and Staghorn corals have undergone a drastic decline in the Caribbean, their hybrid, "Fused Staghorn," is increasing in numbers in parts of the region.

In the Florida Keys, divers from around the country learn how to map shipwrecks and apply their skills on a mysterious 19th Century slave ship.

Little-known animals spend their entire lives in the Gulf of Mexico's cold, deep waters.

The Changing Seasteam meets with researchers in French Polynesia, where scientists conduct extensive habitat mapping to create a one-of-a-kind sea floor atlas.

A co-production with the Khaled bin Sultan Living Oceans Foundation The unique oceanic conditions of the Galapagos Islands serve as a perfect natural laboratory to study how climate change may impact corals in the future.

After sea turtle hatchlings emerge from their nests, they vanish into the sea.

Each year, thousands of tourists interact with the tame southern stingrays that congregate in the shallow waters of Grand Cayman's North Sound.

The unique oceanographic conditions of the eastern tropical Pacific make the area one of the best spots in the world for big game anglers to hook billfish.

Most people are familiar with the pretty tropical fish found in aquariums, but few realize that some of these animals are capable of changing sex.

Shows how recent DNA research has cast doubt on the theory that sponges were the first animals to branch off the "Animal Tree of Life, " a kind of family tree for all living and extinct animals on earth.

Every winter, hundreds of manatees aggregate at Crystal River, Florida.

This episode takes viewers into an area of the remote Pacific, the islands of Maug.

The Blue Heron Bridge in Riviera Beach, Florida is known as one of the best shore dives in the United States.

It is estimated there will be two billion more people on the planet by mid-century.

Lake Okeechobee was once the blue heart of Florida, pumping fresh water down to the Everglades and beyond.

For millennia, the exchange of CO2 between the oceans and atmosphere has been in balance.

The remote Revillagegdo Archipelago off Mexico's Pacific coast is a hotspot for giant mantas that interact with awe-struck scuba divers.

Dr. Denise L. Herzing has dedicated her career to studying a community of free-ranging Atlantic spotted dolphins that live in the shallow, crystal clear waters of the Bahamas Through non-invasive, in-water observation; she researches the animals' social structure, behaviors and communication.

Deep underwater, on a shipwreck near Key West, lives a tiny potential new threat.

While American crocodiles are recovering in parts of their range, their future looks bleak in Jamaica.

Flats fishing is popular with recreational anglers in the Caribbean and the Florida Keys.

California's north-central coast is famous for its natural splendor.

Harmful algal blooms come in many forms, from toxic outbreaks impacting the health of animals and humans, to non-toxic but expansive sargassum mats devastating local economies and tourism.

Stony Coral Tissue Loss Disease is devastating Florida's fragile coral reef ecosystem.

Each winter, a population of humpback whales migrates to its breeding grounds in the Hawaiian Islands.

Blue holes scattered throughout the Gulf of Mexico inspire a team of exploration scientists and divers who set out to uncover the mysteries of what makes them ecological oases.

Ten years after the Deepwater Horizon oil rig disaster, scientists are still studying its devastating impacts on the Gulf of Mexico.