Changing Seas

The deep-sea submersible Alvin has brought explorers to extraordinary places for more than 50 years. Now, as Alvin is poised to continue its revolutionary scientific work, a new set of upgrades will take it deeper than ever before.

Shore-based, catch and release shark fishing is a popular past time in Florida. But is it having a negative impact on sensitive shark populations? Scientists have teamed up with anglers to study the survival rates of the fish and conduct outreach on best practices.

Scientists study the adorable Humboldt penguins that nest along Peru’s desert coastline.

Scientists explore mysterious blue holes scattered throughout the Gulf of Mexico.

Stony Coral Tissue Loss Disease is devastating Florida’s fragile coral reef ecosystem. But all hope is not lost. Dedicated scientists are working hard to find the cause of the disease, treat the ill and restore these cities of the sea to their former glory.

California’s north-central coast is famous for its natural splendor. Only fifty miles northwest of San Francisco’s Golden Gate Bridge lies the Cordell Bank, a magical underwater island few people have ever heard of. Protected inside a National Marine Sanctuary, this oasis is an ecological hot spot for marine life - attracting birds, sea turtles and marine mammals from thousands of miles away.

While American crocodiles are recovering in parts of their range, their future looks bleak in Jamaica. Habitat loss and poaching have led to a drastic decline in the population. Dedicated experts are working to save the species through research, education, and conservation initiatives.

Dr. Denise Herzing has dedicated her career to studying wild Atlantic spotted dolphins in the Bahamas. She researches the animals’ social structure, behaviors and communication. Now modern technology is making it possible to correlate the dolphins’ sounds and behavior, bringing experts closer to decoding dolphin communication.

For millennia, the exchange of CO2 between the oceans and atmosphere has been in balance. Now, with more anthropogenic carbon dioxide in the atmosphere, the oceans are taking up more CO2 as well. This additional CO2 is negatively impacting sensitive ecosystems, making scientists worry how these changes will affect the way carbon is cycled through the seas.

Scientists work with the private sector to develop sustainable offshore aquaculture.

In the remote Pacific, the islands of Maug rise out of the sea. Formed by an ancient volcano, shallow hydrothermal vents are found close to coral reefs inside the submerged caldera. These vents emit levels of CO2 that can be expected in the world’s oceans by the end of the century, making these waters a natural laboratory for scientists studying the impacts of ocean acidification on coral reefs. Co-produced with Open Boat Films.

Until recently there was scientific consensus 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. But recent DNA research has cast doubt on that theory, with some scientists suggesting that ctenophores, also known as comb jellies, are an older lineage.

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. But intense pressures from commercial fishing operations have taken their toll on the numbers of sailfish and marlin in the region. Researchers are studying the animals to provide the data necessary to protect the fish populations from further decline.

After sea turtle hatchlings emerge from their nests, they vanish into the sea. Until recently, their journey was largely shrouded in mystery. Now, as technology advances, researchers are beginning to understand where turtles go during their so-called “lost years.”

The unique oceanic conditions of the Galápagos Islands serve as a perfect natural laboratory to study how climate change may impact corals in the future.

Crinoids have been around in various forms since before the age of dinosaurs. Now experts descend into the deep to study the animals from a submersible.

In the cold, deep waters of the Gulf of Mexico, little-known animals spend their entire lives in near darkness, far removed from our human world. Until now, little research has been conducted on these creatures of the deep, keeping much of their lives a mystery. Then, in April of 2010, the Deepwater Horizon oil rig exploded, setting off the largest marine oil spill in the history of the petroleum industry. Roughly 4.9 million barrels of crude oil gushed out of the well at a depth of 5-thousand feet. In the disaster's aftermath, many questions arose about what lives in the deep waters of the Gulf, and how these animals may have been impacted by the oil. To answer these questions, scientists from the Deep-C Consortium's ecology team conduct regular research trips in the area.

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. One scientist is studying the animals in Belize to see if the hybrid might be better equipped to deal with environmental stressors than its parents.

Join researchers from the Reef Environmental Education Foundation and the Cayman Islands Department of Environment as they study one of the last great reproductive populations of Nassau Grouper. Normally a solitary species, during the winter full moons Nassau Grouper travel, sometimes over great distances, to "group" together and spawn. While most of the known spawning sites in the Caribbean have been fished out over the years, the west end of Little Cayman in the Cayman Islands is home to largest known reproductive spawning aggregation of this endangered species.

Sharks are beleaguered species. The oceans' most formidable apex predators are overfished worldwide for their fins, which are considered a delicacy in many Asian countries. Shark populations have declined by up to 90 percent in some cases. But much is still unknown about the animals. Tiger sharks in particular display behaviors that are not well understood. Known to travel long distances, these fish have a broad diet and spend time in shallow, near-shore habitats as well as the depths of the open ocean. Scientists use satellite tags and DNA forensic tools to better understand their migration patterns. Such information is crucial for resource managers to make more informed fisheries management decisions in the future.

The oceans are part of America's newest medical frontier. In Florida, scientists are studying a variety of marine invertebrates which may hold the key to unlocking the secrets of our own biology. At Harbor Branch Oceanographic Institute in Fort Pierce, researchers are testing sea sponges for their potential anti-cancer properties. At The Whitney Laboratory for Marine Bioscience in Marineland, experts are taking a closer look at horseshoe crabs to better understand how eyes function and change with age. Scientists there are also studying sea slugs for insights into neurodegenerative disorders such as Alzheimer's and Parkinson's disease. What clues will these and other simple organisms reveal about the human body? Are there cures that lie beneath the waves?

In the waters of the western Atlantic and Caribbean, a voracious alien predator has taken hold. Native to the Indo-Pacific, the invasive lionfish is a major threat to biodiversity.

An ancient species of flowering plants that grow beneath the surface of the world's oceans, seagrasses link coastal coral reefs with mangrove forests along the coastline. Today, these "prairies of the sea," along with mangroves, are declining globally. Scientists fear the diminishing vegetation could lead to an ecosystem collapse from the base of the food chain all the way to the top. Changing Seas joins experts in the field as they work to restore Florida's vital mangroves and seagrasses. Seagrasses and mangroves are "hotspots of biodiversity" since they attract and support a variety of marine life. However, damage and removal of these plants continue across the globe at a rapid pace. 'Changing Seas' journeys along Florida's coastline to better understand the significant roles mangroves and seagrasses play within the state.

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. In this unprecedented collaboration, experts from four different agencies unite to count and analyze fish data from select sites. Changing Seas follows highly-skilled science divers as they determine the size of fish populations in hopes of better understanding how fishing pressures and environmental changes affect populations of marine resources within the park.

In the deep waters off Florida's Atlantic coast grow magnificent structures, capable of reaching 300 feet in height. These are the corals of the deep sea. Porcelain-white and centuries old, few humans have seen these delicate reefs. The Ivory Tree Coral, Oculina varicosa, and Lophelia pertusa flourish in harsh, sunless environments, yet these branch-like formations provide food and shelter for a variety of deep water organisms. Rich in biodiversity, this mysterious underwater kingdom is threatened by destructive fishing practices such as bottom trawling. However, a recently proposed 23,000 square mile marine protected area could save these fragile reefs from ruin.

At a time when large fish are rapidly disappearing from the world's oceans, one giant is making a comeback in Florida. The Goliath Grouper was facing extinction when it became a protected species in 1990. Since then, the population has had a chance to recover. Now, some members of the recreational fishing community are pushing to re-open the fishery. But scientists studying the colossal, slow-to-mature fish say such a move would be premature. Changing Seas joins scientists in the field to learn more about the life history of these awe-inspiring fish.