In 1980s, sea otters gradually returned to California's coastlines after being nearly extinct. Their return restored kelp forests, reduced carbon emissions and flooding

Sometimes all it takes to heal an ecosystem is not an elaborate tree-planting project or extensive ocean-cleaning initiative but giving back a predator, its habitat and ensuring its survival. The disappearance of the cute, furry otter in California’s Pacific coast triggered an ecological disaster. In their absence, sea urchins dominated the coast, devouring vast underwater kelp forests, until the seascapes were rendered barren. In the 1980s, the otters were finally returned to the coast with the help of wildlife enthusiasts. Kelp forests quickly returned when they resumed killing sea urchins, changing the underwater environment. The amazing chain reaction that ensued revealed the amazing ability of nature to repair itself: additional habitat for marine life, improved coastline protection, and more carbon storage.

Hunted for Their Valuable Fur

According to a report from ABC News, sea otters were one of the marine mammals that European settlers hunted a lot during the 18th and 19th centuries. A biologist from Sonoma State University named Brent Hughes said that the animals were especially hunted because their fur was very valuable. This led to a lot of hunting, which almost made the species disappear. For about twenty years in the early 1900s, people thought sea otters had completely disappeared from the California coast.

Protection eventually allowed the species to survive. In 1911, an international agreement called the Fur Seal Treaty was created to help protect fur seals. Later, in the 1970s, even stronger laws were passed, such as the Marine Mammal Protection Act in 1972 and the Endangered Species Act in 1973, to provide more legal help and protection for marine mammals and endangered species. A very small group of just a few dozen otters were able to live near Big Sur, which helped them come back later.


Also read: In 1995, 31 grey wolves returned to Wyoming's Yellowstone Park; decades later, 9 beaver colonies are thriving as willow forests recover and erosion risks fall

The Predators That Helped Kelp Forests Recover

Sea otters are more than just cute and friendly animals that live in the ocean.They play an important role in keeping the marine ecosystem healthy. Studies from the University of California, Santa Cruz show that they play an important role in keeping kelp forests healthy.This is because they eat sea urchins and other creatures that eat underwater plants.

Their importance to the ecosystem became very clear after the unusually warm ocean temperatures in 2014. The event happened at the same time as a big die-off of sea stars, which took away another key predator of sea urchins. With fewer predators controlling the urchin numbers, the animals grew in number and caused big damage to the kelp along California's coast.

Researchers from UC Santa Cruz discovered that sea otters greatly increased their eating when the number of urchins went up. Graduate student Joshua Smith and his team found that otters along the Central Coast were eating about three times more urchins than they did before 2014.

A Growing Otter Population

The plentiful food supply, such as sea urchins and mussels, helped the local otter population grow a lot. In the southern part of Monterey Bay, near Monterey, the number of animals increased from around 270 to about 432 after 2014.

By keeping the grazing animals in check, the returning predators made it possible for the kelp forests to start growing back again. These underwater forests offer homes to many sea creatures and also help protect the coastline from damage.

Kelp Forests And Carbon Storage

Kelp is also closely linked to the climate. The World Wildlife Fund says that kelp forests can hold up to 20 times more carbon in each acre than regular forests on land. Studies have shown that marine seaweed systems around the world might move hundreds of millions of tons of carbon into the deep ocean every year.

When kelp dies and sinks to deeper waters, some of the carbon it holds gets trapped in the sediments on the seafloor. That stored carbon can stay there for about a century, which means healthy kelp ecosystems help with the natural process of moving and storing carbon over the long term.

Otters Can Help Seagrass Too

The effect of sea otters goes beyond the kelp. Their way of feeding can also help seagrass meadows in an indirect way, and these meadows are key areas that store a lot of carbon.

Otters eat crabs, which helps reduce the amount of pressure crabs put on animals like snails and slugs that eat plants. Those small grazers eat algae that grows on the leaves of seagrass. If the algae population stays the same, they don't get out of control, which lets seagrass get more sunlight and grow better.

As seagrass grows, it takes in carbon from the air and keeps some of it in its roots. Eventually, that carbon can get trapped in the sediments on the ocean floor, and it can stay there for hundreds of years.

How Otters Helped Heal Elkhorn Slough

When sea otters came back, it affected the coastal marshes in California. NPR covered a study that looked at how Elkhorn Slough in Monterey Bay is recovering ecologically. The research was done by Christine Angelini, a coastal ecologist at the University of Florida, who also helped write the study published in the journal Nature.

The estuary had faced many years of environmental stress. A marine ecologist named Brent Hughes from Sonoma State University says that when a permanent opening to the ocean was made in the 1940s, it caused more tidal energy and made the marshes erode faster.

Other problems compounded the damage. Nutrient pollution caused big algal blooms that took over the marsh plants, and rising sea levels slowly covered parts of the habitat. At the same time, the number of shore crabs grew a lot.

Around 100 Otters Transform The Marsh

Starting in the 1980s, sea otters slowly came back to the area, partly because people worked to protect them. Their increasing presence once more changed the food web.

The otters ate a lot of the crabs, which helped the ecosystem return to a balanced state. Today, Elkhorn Slough has about 100 sea otters, which makes it the place with the most sea otters in California.

The recovery of the marsh also affects people in important ways. Healthy coastal wetlands help soak up and slow down floodwater, giving communities a natural defence against flooding.

Whales And Otters: Small And Large Climate Allies

Sea otters are not the only ocean animals that play a role in the planet's carbon cycle. Whales also have an important role because they are very large and live for a very long time. The International Fund for Animal Welfare says that a large whale can hold about 33 tonnes of carbon dioxide in its body throughout its life.

Their contribution does not end there. Whale poop gives nutrients that help phytoplankton grow. Phytoplankton are tiny creatures that are important for the ocean's food chain and also help take carbon dioxide out of the air. Phytoplankton help make about half of the oxygen that is produced around the world.

Whales are big animals in the ocean, but sea otters show that being big isn't the only thing that matters when it comes to affecting the environment. A small predator can influence big changes by controlling certain animal species, which then affects many parts of the environment, like kelp forests, seagrass areas, coastal wetlands, and even how carbon moves through the world.

While not as big and majestic as the whale, the furry little otter also plays a role in keeping the ecosystem carbon-free.