Many travel from far destinations to experience San Francisco clam chowder or fresh seafood dishes but some bay area residents are starting to realize that not all shellfish is welcome. On a local scale, we are also suffering from environmental invaders. In the bay area, and other local communities, waters are continuously being contaminated by the zebra mussel. Zebra mussels have managed to contaminate large areas of the world and have numbers that are steadily climbing considering their fast reproduction rate. With our need for constant consumption, cargo ships from China, Japan and many other countries are continuously trafficking our bay, carrying goods from all over the world. Zebra mussels are a marine hitchhiker on these cargo ships by tagging along in the ballast water of the ship. The ballast is filled with water at the ships origin, and is sometime emptied upon arrival at its destination, leaving behind organisms that are not native to the waters. The zebra mussel is one such organism. With the ability to multiply quickly, the zebra mussels have become invasive to small marine species which cannot compete with the alien mussel. Zebra mussels are not only killing off marine species but they also create clogged piped and infest waterways. “Zebra mussels have inflicted tremendous damage to native ecosystems and to facilities using water, like power plants and municipal water suppliers. Millions of dollars have been spent by water users, to control and eradicate zebra mussels”. Recreational boats contaminate California lakes and reservoirs without being properly treated by educated professionals. Zebra mussels are an example of bioinvasion that burdens California residents, and while these mollusks threaten our local ecosystem, we also have larger, frightening global bioinvasions as well.

There are an endless number of species in our waters and countless species that have been unaccounted for to date, that are at serious risk of destruction from biodiversity threats. With over 100,000 synthetic chemicals in our atmosphere, existing species have little chance of survival simply because they have not evolved with these deadly chemicals. Many marine ecosystems are fragile and extremely vulnerable to damage. Bioinvasion changes these ecosystems greatly and countries around the world are recipients of unwanted visitors each year. Obviously, The San Francisco Bay has not been immune to these unwanted visitors. If we are seeing bioinvasions expanding rapidly locally, it’s only evident that the rest of the world is being damaged too.