Invasive Species

"I’ve always known that clams, seaweed, and all this other stuff live under the Bay, but I never knew there were such things as exotic species."

By Genysys Sanchez

I see the San Francisco Bay almost every day. But I’m so used to it that I’ve never thought much about it.

Then, I went to the Romberg Tiburon Center to interview marine biologist Julian Herndon about invasive species in the San Francisco Bay. What I learned was surprising.

I was expecting Julian to be old, with a big white lab coat with a white beard to match. To my surprise, he looked more like a college student than a marine biologist. Julian told us about growing up in Costa Rica, his research trips to the coast of Russia and Antarctica. He preferred that we talk to him in Spanish, since he said he hadn’t spoken it for about six months.

The research center was located in an old World War II naval center. As soon as we arrived, I noticed the concrete pillars of all sizes lined up alongside the water. Julian told us that the smaller pillars were used as weights for a huge net that was placed under the Golden Gate Bridge during World War II to keep enemy submarines out of the Bay.

I’ve always known that clams, seaweed, and all this other stuff live under the Bay, but I never knew there were such things as exotic species, which come from other parts of the world and are brought to the Bay by ships. Ships take in water when they balance their cargo. During this process, they bring in species that inhabit the surrounding water, so when the ship goes somewhere else and releases the water, it’s also releasing the exotic species.

The problem with exotic species getting into the Bay is they reproduce very quickly and can take over. The Asian clam is one of these species. Julian explained that these clams cover the bottom of the Bay, and filter out native minerals and organisms, including the phytoplankton that species depend on. Julian says this reduces bio-diversity in the ecosystem that exists in the Bay, which makes it more vulnerable to severe weather and environmental changes, such as global warming.

There isn’t much that can be done to stop these species from invading the Bay since, like Julian mentioned, they’re just trying to survive. But there are ways of preventing more exotic species from entering. One way is not to dump unwanted fish or other marine pets into the Bay. Another way is to avoid keeping exotic plants in your backyard.

This whole marine experience was pretty interesting. We rarely see stuff like this exposed in the media, at least the media I see and read. It makes me wonder how many other issues are out there that young people like me aren't aware of because of lack of exposure.

-This story was produced by Youth Radio’s Environmental Desk in association with National Geographic.