Climate change may be claiming another casualty – the kelp beds off La Jolla.

“The kelp habitat in La Jolla has been drastically reduced for those animals feeding up in the seasonal water column where the surface water is warmer,” said Ed Parnell, a Scripps Institution of Oceanography researcher. “Warmer water decreases the amount of nutrients in it for kelp to grow.”

Parnell, who studies the biological impacts of climate change, added that though there has been patchy kelp improvement in some areas off La Jolla, “huge chunks of kelp off Marine Street north of La Jolla Cove have not grown at all – it’s gone.”

Kelp is a type of algae resembling a plant or underwater tree, which grows vertically in the water forming a canopy over the ocean surface. A kelp forest is an area where the kelp grows in thick, dense clusters with a very lush canopy.

Kelp forests are important habitats because they provide food and shelter for marine life, remove harmful carbon dioxide from the ocean and atmosphere, and furnish the ingredients for products like toothpaste and ice cream, as well as provide a large amount of seafood.

Parnell has been studying gradually rising ocean temperatures over time, which appears to have been decimating kelp beds in northern La Jolla. He noted that a 2016 El Niño (warmer waters) led to a major kelp die-off along the West Coast. He added that was followed by a cooler water cycle in 2017-18 that should have revived kelp. But he added that is far from living up to expectations.

The marine scientist noted kelp is temperature-sensitive, pointing out that periodic ocean temperature variations can wreak havoc in the ocean environment.

“Water temperatures during El Ninos can be as much as 2 to 6 degrees warmer (at various depths), which is a huge difference,” noted Parnell, adding temperature readings that have been taken at Scripps Pier since 1916 reveal “a dramatic upward shift in the temperature trend, starting in the late ’70s and going all the way up to now. It’s just profound.”

Parnell explained that excess heat gets stored in the ocean. “If it wasn’t for the ocean, the planet would already be unlivable,” he said noting, “When there’s an El Niño, which typically occurs in cycles every 2-8 years, a lot of that pent-up heat is released back into the atmosphere.”

To put the heat-absorbing power of the ocean in perspective, Parnell said the amount of heat naturally stored in the ocean since 1950 is “enough energy to power human society, at its present state of energy use, for the next 450 years.”

“Even with the relatively recent La Nina (colder waters), the La Jolla and Point Loma kelp still doesn’t seem to be doing well,” said Parnell adding, “That’s unusual because that should have been good for them to grow.”

In the meantime, Parnell pointed out that “we’re coming into another El Niño,” which he noted is especially bad because La Jolla’s kelp hasn’t yet recovered from the last one.

“This heat is going to stay in the ocean for generations,” concluded Parnell. “It’s not going to go away. Even if we stopped using fossil fuels tomorrow, the heat would still be increasing in the ocean. People just don’t realize it, it’s really a catastrophe.”

KELP FORESTS

There are two giant kelp forests in San Diego: the La Jolla Kelp Forest y el Point Loma Kelp Forest. La Jolla is a shallow kelp forest while Point Loma is a deeper kelp forest. Because they’re at different depths, you’ll notice some big differences between them in terms of marine life and diving conditions. The La Jolla Kelp Forest is the most accessible kelp bed in San Diego and can be easily reached from La Jolla Cove without a boat.

La Jolla Kelp Forest ranges from 30-50 feet, and strong currents are rare. That makes it a great dive site for beginners and for those who prefer an easygoing dive. When you dive into the La Jolla Kelp Forest, you can also check out the big reefs and swim-throughs at La Jolla Cove. Compared to Point Loma, La Jolla is a more dynamic location for scuba diving. It’s easier to find marine mammals, sharks, and rays at La Jolla.

The Point Loma Kelp Forest is located off the Point Loma peninsula, near San Diego Bay. Marine biologists consider this to be one of the largest, healthiest kelp forests in California. The Point Loma Kelp Forest is so large that it contains a huge variety of dive sites within its enormous kelp beds. Due to its location, this kelp forest can only be reached on a boat dive. For the most part, La Jolla and Point Loma host the same type of marine life, which includes sharks, spiny lobsters, crabs, bass, and eels.