Climate Action for the Ocean

Climate change and ocean acidification are affecting ocean health—and our own survival—in profound ways.

Fortunately, the ocean is resilient and can recover if we take action.


Excess Carbon Dioxide is Changing the Ocean

Warming Waters

When people burn fossil fuels such as coal, oil and natural gas, we release carbon dioxide into the atmosphere. That carbon dioxide, along with other heat-trapping gases, acts like a blanket that keeps getting thicker around the Earth. The heat that would otherwise be radiated out into space causes the temperature to rise.

The ocean absorbs 80-90 percent of this extra heat. As the ocean's surface warms, it sets off a cascade of impacts including sea-level rise, stronger storms, shrinking sea ice and coral bleaching. Some marine species are moving toward the poles as the ocean warms. Others are less able to adapt to the changes.

A More Acidic Ocean

Our carbon dioxide emissions are affecting the ocean in another major way—and it's about chemistry. Ocean acidification happens when the ocean absorbs some of the carbon pollution we've pumped into the air, triggering a chemical reaction that lowers the ocean's pH. The ocean is already 30 percent more acidic than it was before people started burning fossil fuels.

Acidic seawater makes it tougher for shelled marine animals to survive. The fragile shells of tiny sea snails called pteropods, for example, are thinning as the pH level drops. These impacts ripple through the marine food web, affecting many of our favorite seafood species.


What You Can Do

Climate action means creating a better world for people and the planet.

Working together, we can reduce our reliance on fossil fuels, slow global warming and ocean acidification, and adapt to the impacts already in motion.

Southern Sea Otters

Raft of southern sea otters

The Monterey Bay Aquarium's Sea Otter Program has been studying the threatened southern sea otter since 1984 with the aim of understanding threats to the population and promoting its recovery. We also rescue, treat and release injured otters; raise and release stranded pups through our surrogate program; and seek homes for sea otters that can't return to the wild.

Sea Otters Under Siege

Southern sea otters (Enhydra lutris nereis) once ranged from Baja California to the Pacific Northwest. But, by the 1920s, they were almost extinct due to intensive hunting. They were listed as threatened under the Endangered Species Act in 1977. We and our partners have contributed to the protection of the sea otter population in California.

Recent research by the U.S. Geological Survey and the Aquarium suggests that the sea otter population growth rate is limited by food availability. Meanwhile, the risk of a major oil spill remains a serious threat.

Why Are Sea Otters Important?

Sea otters are an iconic species, representing the beauty and diversity of life in Monterey Bay. They're also a keystone species, determining the kinds and health of species in nearshore environments. They eat sea urchins and other invertebrates that graze on giant kelp. Without sea otters, urchins prevent kelp forests from forming important habitats for many animals. Similarly, their consumption of crabs in estuaries reduces predation on snails. The snails graze algae that otherwise choke eel grasses.

Sea otters are also good indicators of ocean health. Since they are a top predator of invertebrates along the California coast, changes in their health can make scientists aware of variations in the ocean environment itself.

Sea Otter Recovery

By 1911, when sea otters gained protection under the North Pacific Fur Seal Treaty, a small group of perhaps 50 otters survived along the remote Big Sur coast. Since then, they've slowly expanded their range and grown in number to nearly 3,000. As of 2014, their range extends from south of Half Moon Bay in the north to south of Point Conception in the south—only a small part of their historic range.

Southern Sea Otters

Raft of southern sea otters

The Monterey Bay Aquarium's Sea Otter Program has been studying the threatened southern sea otter since 1984 with the aim of understanding threats to the population and promoting its recovery. We also rescue, treat and release injured otters; raise and release stranded pups through our surrogate program; and seek homes for sea otters that can't return to the wild.

Sea Otters Under Siege

Southern sea otters (Enhydra lutris nereis) once ranged from Baja California to the Pacific Northwest. But, by the 1920s, they were almost extinct due to intensive hunting. They were listed as threatened under the Endangered Species Act in 1977. We and our partners have contributed to the protection of the sea otter population in California.

Recent research by the U.S. Geological Survey and the Aquarium suggests that the sea otter population growth rate is limited by food availability. Meanwhile, the risk of a major oil spill remains a serious threat.

Why Are Sea Otters Important?

Sea otters are an iconic species, representing the beauty and diversity of life in Monterey Bay. They're also a keystone species, determining the kinds and health of species in nearshore environments. They eat sea urchins and other invertebrates that graze on giant kelp. Without sea otters, urchins prevent kelp forests from forming important habitats for many animals. Similarly, their consumption of crabs in estuaries reduces predation on snails. The snails graze algae that otherwise choke eel grasses.

Sea otters are also good indicators of ocean health. Since they are a top predator of invertebrates along the California coast, changes in their health can make scientists aware of variations in the ocean environment itself.

Sea Otter Recovery

By 1911, when sea otters gained protection under the North Pacific Fur Seal Treaty, a small group of perhaps 50 otters survived along the remote Big Sur coast. Since then, they've slowly expanded their range and grown in number to nearly 3,000. As of 2014, their range extends from south of Half Moon Bay in the north to south of Point Conception in the south—only a small part of their historic range.