Underwater kelp forests are sometimes called the rainforests of the sea, but - like the verdant jungles on land - the vast beds of seaweed are disappearing, hurting fisheries and coastal communities worldwide. A project off the coast of California is helping to restore them.
Divers are working in the waters off the Palos Verdes Peninsula in places known as barrens, which once were home to thriving kelp forests. Today, these parts of the seabed are thick with sea urchins, creatures that have proliferated because of pollution and other human activities. The divers are killing some of urchins to thin the population, which is sickly and malnourished. This restores the natural balance, says David Witting of the National Oceanographic and Atmospheric Administration.
“That will allow the kelp to establish itself," he said. "Once there's a healthy kelp forest system, the urchins tend to feed off of the broken-off pieces of adult kelp, rather than foraging on the juvenile kelp.”
Scientists regularly head out to sea for the restoration work on the 60-hectare project.
Tom Ford of the Santa Monica Bay Restoration Foundation
says kelp forests have been depleted in temperate waters in many parts of the world.
“That list of places would include Korea, Japan, New Zealand, Tasmania, Australia, South Africa, Chile, and then back up the coast here into North America,” he said.
The restoration work is helping young kelp plants take root and flourish. And the return of healthy kelp forests to this offshore area provides a habitat for sea life and again creates a place of natural beauty.
“It's very much like being in a forest under water. So you have that feeling of being under water, but you also have that filtered light," said fisheries scientist David Witting. "There are fish in all parts of the water column. There are tremendous amounts of diversity.”
This intervention is taking place in other places as well, including Canada and South Korea, where coastal environments are under pressure, explains Tom Ford.
“As our human population increases and people are moving into the cities, we are putting more pressures on our coastal environments, so that the pollution problem seems to be getting greater," he said. "At the same time [there are] more mouths to feed, so we're trying to get more and more out of our oceans to accomplish that.”
Many of the techniques to restore the world’s kelp forests are being developed here. A coalition of environmental and scientific groups, and local fishermen, are supporting the work. All hope to see the return of a healthy population of marine life. Scientists say the project shows that with some human help, the rainforests of the sea can flourish once again.