Coastal Sea Life Threatened by Diminishing Kelp Forests

THE WHALE SURFACED AND EXHALED, creating a spout that shot upward into the morning fog. We trekked along a trail following the coastline as the large sea mammal swam and fed within stretches of rich kelp forests. Stopping at bluffs providing closer vantage points, my wife and I listened attentively as the whale took a huge breath of air whenever it surfaced. The sound is etched into our memories; a shared experience we’ll always cherish.

Gray whales are filter feeders that prefer shallow, coastal waters, and kelp beds are their feeding grounds. They dive to the sea floor and roll onto their sides in order to strain for food. Sucking up everything in their path (yes, unfortunately this includes microplastics), the whale then rises and all that’s captured is sifted through its baleen plates. Basically, everything is spit out with the exception of their invertebrate prey—tiny amphipods (shrimp-like animals that live inside the sediment), bottom-dwelling crustaceans, worms, and mollusks.

A grey whale surfaces and spouts while feeding in Northern California kelp beds.

Gray whales aren’t the only sea life who rely on these areas for food. A wide range of fish live within kelp forests, along with sea lions and seals that feed on these schools of fish. Sea otters take refuge from sharks and storms, and eat red sea urchins living within the kelp. Bristle worms, scud, prawn, snails, and brittle stars feast on the holdfasts that anchor kelp to the ocean floor. Kelp beds are also home to sea stars, anemones, crabs, and jellyfish.

A number of seabirds are attracted to feeding gray whales and take advantage of invertebrates that escape the filtering process. Other birds such as crows, warblers, starlings, and black phoebes, feed on flies, maggots, and small crustaceans. Gulls, terns, egrets, great blue herons, and cormorants feed on fish and invertebrates. Kelp forests also provide shorebirds refuge from storms. Everything in or near a kelp forest is connected in one way or another.

The balance of the coastal ecosystem will be changed if the present depletion of kelp beds continues.

These underwater forests are as important to the oceans as our high Sierra forests are to the land. Like trees, seaweed absorbs carbon emissions and provide critical habitat and food for a wide range of species. But when climate change triggered an explosion of purple urchins off Northern California’s coast, the urchins went on a feeding frenzy and the kelp was devoured. In a matter of five years (2013 and 2017), 93 percent of bull kelp along the Northern California coast has been lost.

The downward spiral of California’s kelp forests quickly progressed due to warming water temperatures. First, the sea stars dissappeared, then the purple urchins took over, ravenously eating until the bull kelp forests were gone. The red abalone starved. Their fishery closed. Red sea urchins starved. Their fishery collapsed. The result: long stretches of underwater areas void of life, resembling deserts, along with economic devastation to many local fisheries. This same scenario is making its way up the western coast as far north as Alaska. Another marine heat wave for the California coast is forecast for this winter.

Dying kelp forests are a worldwide event. Off the east coast of Tasmania, 95 percent of the kelp has disappeared since the 1940s. The loss has been so stark that the Australian government listed Tasmania’s giant kelp forests as an “endangered ecological community.“ Along England’s West Sussex coastline, from Selsey to Camber Sands, there was once was an expansive habitat of kelp forests, but they have dramatically declined over the last 40 years. How many are left is yet to be determined.

All life along the coast, big and small, will be affected if present trends continue.

After days of whale-watching, we drove up the coast to the city of Fort Bragg. After breakfast one morning, we walked along the main street and came across the Noyo Center for Marine Science. It was there that we found answers to our questions about whales, other sea life, and diminishing kelp forests. The Noyo Center for Marine Science provides marine research, education, and conservation. Centers like these are invaluable. Through education, they serve as a first line of defense against threats to our environment and the ramifications of global warming.

I’ll never forget the sound of a whale breathing as it fed along a long stretch of northern California kelp forest. My hope is that these magnificent creatures can continue to live along our coast, and future generations can bear witness to their beauty.

“The number of living creatures of all Orders, whose existence intimately depends on the kelp, is wonderful… I can only compare these great aquatic forests of the southern hemisphere with the terrestrial ones in the intertropical regions. Yet if in any country a forest was destroyed, I do not believe nearly so many species of animals would perish as would here, from the destruction of the kelp.”

—Charles Darwin, June 1, 1834, Tierra el Fuego, Chile