A clam smaller than a penny stealthily enters San Francisco Bay waters. It begins quickly devouring the tiny plankton at the base of the Bay’s food chain, causing small local fish to starve. It multiplies fast, soon overcrowding native species. The clams absorb toxic pollution at higher rates than other clams, poisoning the fish and ducks that eat them. And now scientists are at a loss. This clam population has grown so large so fast, there’s no way to get rid of them.
Invasive species like the Asian overbite clam are wreaking havoc on San Francisco Bay.
More than 300 non-native species have invaded the Bay and Delta. That’s a higher invasion rate than any other California waterway.
These invaders often arrive here via ocean-going ships that take on water at various ports, to stabilize their weight during the voyage. When a ship reaches its destination, it dumps out this “ballast water,” which can contain up to 20 million tiny stowaways, the larvae of creatures from a previous port.
Over a decade ago, frustrated by inaction, Baykeeper advocates forced regulators to enact tough statewide regulations on ballast water. The rules required California to steadily decrease the introduction of invasive species by 2020, and bring it down to zero by 2030.
Now, California is considering delaying these requirements. It’s doing so partly because the shipping industry procrastinated on developing the necessary technology to fully remove invasive species from ballast water.
Baykeeper scientists recently urged state regulators not to relent. We need to stop this hostile takeover of the Bay. Baykeeper advocated for the state to step up enforcement. And we also asked regulators to require new procedures for ships to exchange their ballast in the ocean, where these species can’t survive, before entering SF Bay. That will improve the situation, even if phasing in the technology takes longer than planned.
In addition, we supported experimenting with the use of floating barges to decontaminate ballast water from ships coming into the Bay.
We’ll keep advocating to keep invasive species out of San Francisco Bay, for the health of Bay species and the entire ecosystem.
Photo by Dan Brekke, Flickr/CC