An explosion in the sea urchin population threatens kelp and seagrasses along California’s coast. Playful sea otters to the rescue! These spirited creatures have a taste for seafood, and it’s good they do. They are a keystone species—creatures of critical importance in the food chain. Their place in that chain helps revive ocean plant life.
Off the California coast, the natural order of God’s design is evident. Larger creatures prey on medium-sized organisms which feed on small ones—and so on, from whales to plankton. Somewhere in the middle we’ll find otters, kelp, urchins, and eelgrass.
In the mid-2000s, disease wiped out large populations of the sunflower sea star. These large (three feet or more!) marine animals are sea urchins’ main predators. Sans sea stars, the spiny, bottom-dwelling sea urchin numbers exploded. They blanketed the seafloor and prevented nutrient-rich, carbon-absorbing kelp from growing through. If any kelp did spring up, the little urchins ate it.
Jessica Fujii helps manage a sea otter research program. She coauthored a study with researchers from the University of California Santa Cruz and the U.S. Geological Survey. Her team discovered that introducing sea otters can ease the sea urchin problem.
Happily for the kelp and humans who enjoy clean air, sea otters don’t mind chowing urchins—God’s food chain! Without being overgrazed, kelp forests continue to grow and play a natural role in a healthy environment.
Closer to shore, sea otters help seagrass flourish too.
Fertilizer runoff and other environmental issues contributed to a global decline in eelgrass. Like kelp, eelgrass helps clean the air humans breathe, provides a vital food source, and supplies homes for a variety of sea life.
Sea slugs nibble algae off seagrass leaves. They help keep the leaves clean and healthy. But crabs see slugs as a delicious meal. When crabs eat too many slugs, seagrasses become sickly. Sea otters to the rescue again! The otters eat the crabs, and more otters mean fewer crabs to prey on slugs. The safeguarded sea slugs are free to nosh on eelgrass algae.
The ocean ecosystem is a miracle of God’s creative genius. Seeing its workings is rewarding for Fujii. “Even after over a decade of doing this work, I love watching otters and seeing how they’re interacting with their environment,” Fujii says. “Having a healthy ecosystem is really important . . . and sea otters have a really important role to play in that.”