o the urchins are fat and happy and sassy,” said Curtis. Although urchins will admittedly eat a reef barren, he asserts they won’t when there’s enough kelp to go around.
But Caruso thinks that could be temporary. “As long as the kelp’s doing okay it will keep the urchins satiated, no problem,” she said. “But if we were to have a catastrophic event, like another El Nino, that could wipe out the kelp beds.”
In the early 1990s, a series of warm El Nino ocean currents swept north to typically cooler ocean habitats. The warmer water killed nutrients needed for marine animal and plant life, which subsequently killed a lot of marine animals and plants. “All of a sudden, the kelp disappeared,” explained Caruso. Another El Nino, she said, could easily tip the balance. “All of a sudden, those urchins are going to get hungry and then they just eat everything that starts growing.”
Transplanting kelp is not all it’s cracked up to be, said Curtis. It takes more luck than labor. “Transplanting never brings back the kelp,” he said. “All it does is it puts the seed source out there. You just need to wait until the environmental conditions get right and then nature takes over. But if there’s no kelp there and the conditions are right, nothing happens.” Curtis said his team planted about 1,000 kelp plants at two depths, evenly split, just in case El Nino comes ‘round again. One depth was about 25 feet, the other and colder, 50 feet plus.
Even when high surf and strong tides pull kelp to shore in smelly piles and people start complaining, “there’s never too much kelp,” he said. “That’s the normal course of things. It’ll come and it will go.” Curtis has survey records dating back 50 years and said the amount of kelp bobbing offshore now is normal. “It’s actually way down from what it was in 1911 when they did the very first survey,” he said.
Biologist Mike Curtis measuring kelp plants per acre off Cleo Street in Laguna Beach last week.
Underwater kelp forests off Laguna’s coastline.
Biologist Nancy Caruso with kelp-munching urchins in Shaw’s Cove two years ago.