Kelp Has Arrived . . . and It’s Raising a Stink

ENVIRONMENT

Teachers: Scroll all the way down for a short list of key resources in our “Teachers’ Toolkit.”

Discussion Ideas

Laguna Beach, California, is awash in kelp. What is kelp, and why does it stink? Our media spotlight, “Kelp Holds Fast and Holds Up,” might give you some help.
- Kelp is a giant type of seaweed. Seaweed is a type of algae (specifically, brown algae).
- The kelp washing up on the beach is a rotting organism, and, in general, dead things stink. (That’s a good life lesson to keep in mind.) The bacteria that are decomposing the algae give off a strong scent that is unpleasant for human beings but tantalizing for the sand flies that, according to the article “nibble on the seaweed and hide in its piles.”

Read through our fun media spotlight on the life and times of California’s two species of kelp: bull kelp and giant kelp. Which type do you think is washing up on the shores of Laguna Beach? Why?
- Laguna Beach’s kelp is probably giant kelp. “Giant kelp and bull kelp are indigenous to cold, shallow, sunny waters along the Pacific coast, from Alaska to Baja California, Mexico,” according to our media spotlight. “Bull kelp are more common in the northern part of the range. Giant kelp outcompete their sister species starting around Central California.”

The LA Times article says that strong storms contributed to tearing the kelp from their beds in the shallow Pacific. When strong winds blow through terrestrial forests, few trees tumble. Why are kelp forests so easily uprooted? (Our media spotlight will give you a clue!)
- Simple: Kelp don’t have roots. Instead, they have gnarled structures called holdfasts attaching them to the ocean’s rocky (not sandy) substrate. Holdfasts are sturdy, but they can be easily ripped from the substrate by strong waves, sending the entire seaweed adrift in the ocean.