Japanese Kelp an Unknown Factor in Local Ecology

By GAIL GALLESSICH

An aggressive Japanese seaweed is making its way around the world, invading foreign harbors. It arrived in Southern California in 2001, including Santa Barbara's harbor. UCSB researchers have received a grant to study this invasive species.

The research that the UCSB scientists will perform on the invasive kelp will focus on answering questions about reproduction, the likelihood of interbreeding, and how the microscopic seed stocks of the different kelps will compete with each other.

"Once you've got it, all you can do is limit it," said David Chapman, professor of ecology, evolution, and marine biology, and principal investigator on the grant. "You can pull up a big one, but you leave behind seed stock."

Since the seed plants are microscopic, eradication is virtually impossible.

The golden-brown Japanese kelp, Undaria pinnatifida, is native to the Sea of Japan and is common to the coasts of Japan, Korea, and China. The kelp is cultured as a fresh and dried food, called wakame, in several countries.

National Sea Grant will provide the $98,000 in funding over two years. Graduate student Marla Ranelletti is the key researcher working with Chapman on this project.

Their research aims to predict possible long-term impacts and to develop preventative measures. The work includes increasing public awareness of this alga and minimizing its spread.

An educational program is in the works. "We want to explain what it is and what to do with it if you find it," said Chapman. "If you see it on a hull, put it in a bag and take it in—don't just drop it overboard."

He explains that another kelp, called Macrocystis (which typically grows to 75 feet), is a commercial crop in Southern California waters as well as an important breeding ground for marine life. Chapman is uncertain how much of a competitor the Japanese kelp will be to Macrocystis.