A marine camel is a Revenous Ecosystem Engineer of the highest order. To stay warm and healthy, they eat a quarter of their body weight every day, repeatedly collecting bivalves like urchins, crabs and clams by diving under the sea. “As much as they eat to survive in their environment, they have a really drastic effect on those habitats and they are extremely positive,” says Fujii. (Another program off the coast of California has tried to bring back a different kind of “archin slayer” – human divers.)
Archin preserves kelp to keep the population under control, which is vital to the ecosystem in two main ways. First, the forest is home to fish, which is a source of food for birds and other marine mammals, such as marine lions. Second, seaweed is a part of what scientists call a “blue carbon” ecosystem, meaning a coastal or marine region that isolates carbon. (Other areas include wetlands and mangroves.)
But it is difficult to measure exactly how much carbon is produced in a healthy kelp forest. For example, a redwood tree holds a huge size for hundreds of years, which locks up a lot of carbon on a long-term scale. (Unless it catches fire, in this case the carbon goes back into the atmosphere.) Things tend to flow more underwater. All kinds of craters, including marine urchins, are nibbling at kelp — and emitting carbon. Also, the churning sea shatters the forest into pieces, which fall to the bottom of the ocean and decompose, releasing the stored carbon. So a kelp forest is constantly eroded and grows again, separating and releasing carbon.
It’s hard to be sure how long the carbon stays stuck. “The fate of all these kelp is not well understood,” Wilmers said. “Imagine that all the things that are becoming sloppy are just sinking in the deep sea and will not come back like 1,000 years ago. This is a much more significant carbon sequestration benefit than just being sloppy and decomposing immediately and returning directly to the atmosphere. ”
With that uncertainty in mind, Wilmers estimates some of the potential carbon benefits of a healthy otter population further north along the Pacific coast between the Canadian border and the tip of the Aleutian island. If a kelp forest grows well and half the carbon it absorbs is isolated in the deep sea, it would be equivalent to canceling emissions from 5 million automobiles. Even if only 1 percent of the carbon remains in the depths, it would be equivalent to emissions from 100,000 cars.
In the Gulf of Monterey, otters don’t just protect kelp. They are elkhorn sulph, a large tidal wave where they stimulate the growth of ilgrass, another coastal plant that isolates carbon – although otters affect the plant in a more indirect way. Otters eat crabs, which in turn eat invertebrates like marine slag, which eat algae that grow in ilgrass. Reducing the number of crabs hunted in the slugs actually helps the ilgrass because when the slugs remove the algae, it keeps the plants clean, allowing them to absorb more sunlight. Thanks to the return of the Otters, the amount of Ilgrass in Elkhorn Slow has increased by 600 percent over the last three decades.