What do you call a helpful piece of kelp? Kelp-ful!

Aside from its ability to be made as a witty pun, kelp has gained attention for its potential as a bio-stimulant, especially at USC. Macrocystis pyrifera, or giant kelp, grows along the Pacific coast of North America, stretching from Southern Alaska to Baja California. 

Giant kelp has four key structural features. The blades act as leaves, carrying out photosynthesis to produce energy. The holdfast anchors the kelp to the seafloor, while the stipe, similar to a stem, connects each blade but does not transport nutrients, unlike stems. Between the stipe and each blade is a gas bladder, which keeps the kelp upright, helping it reach sunlight to photosynthesize. Despite its simple structure, giant kelp is among the fastest-growing organisms in the world. Under ideal conditions, this kelp can grow up to two feet per day.

Bernadeth Tolentino, a Molecular Environmental Biology PhD student, studies kelp’s fascinating characteristics, particularly its symbiotic relationship with bacteria that can be used to aid its growth. What initially drew her to study kelp was its potential to be used as a root stimulant in agricultural settings.

“Because it is the fastest-growing organism on the planet, and with that biomass production, we can really take advantage of using it commercially,” she said. 

Utilizing kelp as a bio-stimulant involves collecting, cleaning, and sonicating. The process of sonicating involves sound waves that break the cell walls of kelp, allowing it to release compounds that can stimulate root growth in plants, as explained by Tolentino.

Despite its potential, giant kelp’s declining populations may create barriers in the expansion of this new biotechnology. 

“We have to keep in mind that the lifespan of kelp farming in [Southern California] may or may not be as long term as we would like it,” Tolentino said. 

Giant kelp thrives in cooler oceanic environments that fall within 42 - 72°F, with temperatures outside of this range causing stress on the organism. As a result, increasingly limited environmental conditions caused by global warming make it difficult to commercialize the use of kelp. These environmental changes motivate Tolentino, as studying the microbial community of kelp may help expand its ecological niche.

Overall, Tolentino wants to encourage the conservation of giant kelp.

“As we start thinking of ways we can use kelp as a resource, we need to take a pause and understand that we might be losing it because of environmental and anthropogenic effects,” she said.