Kelp abundant on Laguna beaches over the summer
This past summer was memorable not only for periods of extreme heat, but also for the amount of kelp that washed ashore on Laguna’s beaches.
City officials and environmentalists noted that the past few months were unlike any other period because of the amount of kelp that collected in piles, called wrack, on the sand at places such as Main Beach and just north of Laguna in Crystal Cove State Park.
The seaweed bundles, while a haven for annoying flies and pungent smells, are living ecosystems, marine biologist and kelp aficionado Nancy Caruso said.
Caruso has led a mission to revitalize the sea plant in forests off the coasts of Laguna and Newport Beach over the past 10 years and is recognized for organizing the annual Kelp Fest at Main Beach each spring. The event’s purpose is to educate the public on the plant’s environmental benefits.
Kelp wracks play a pivotal role in the natural food chain, Caruso said.
Tiny invertebrates, such as beach hoppers, also known as sand flies, nibble on the seaweed and also hide in the wracks. The invertebrates, in turn, are a food source for shore birds.
Kelp on the sand can be pulled back into the ocean by high tides and reproductive spores released, Caruso said.
Nutrients can also seep into the sand and return to the ocean as the tide recedes.
An excess of kelp wracks washed ashore in Laguna last summer. City Public Works Director Steve May said it was the most he has seen in one summer since he started working in Laguna in 1995.
Caruso pointed to warmer sea temperatures and large storm swells that dislodged the kelp from reefs.
Warmer water from the tropics has fewer nutrients, thus kelp starve and release from the reefs, Caruso said.
“On top of [the warmer water], we had more south swells this summer than I can remember,” Caruso said. “All of that created lots of kelp on the beach.”
She noticed something drastically different during one scuba dive off of Crystal Cove in late August, when Hurricane Marie off the Baja coast was creating massive waves along Southern California beaches.
"[The storm] ripped out 98% of the kelp from the reef,” said Caruso, who added that was good for fostering new plant growth.
To keep beaches clean, city crews occasionally scoop up kelp wracks and take them to an area in Laguna Canyon where they are left to dry in the sun, May said.
Once dried, the kelp is taken to Waste Management’s recycling facility in Irvine, where it is combined with other “green waste” materials such as tree branches and leaves, and then taken to another facility where it is turned into a cover for landfills, company spokeswoman Eloisa Orozco said.
Caruso said she would like to see kelp used for other purposes, such as biofuel or fertilizer, though she
would argue that kelp should be left undisturbed on the shore, waiting for the tide to pull it back into the ocean.
What some people consider stinky, Caruso calls pleasing.
“I think [kelp] smells good,” she said. “I want people to understand that kelp is supposed to be here.”
Kelp isn’t the only living organism along the shoreline that the city keeps tabs on.
During grunion season, which runs from March through August, trucks are not allowed to scoop kelp that rests below the high water line — the tide’s farthest point in the sand — since they could disturb grunion eggs, May said.
The federal Fish & Wildlife Service scolded Laguna last summer for digging into the sand, May said. Crews must pick up kelp by hand during the five-month period, May added.