Invasive Species in the Intertidal
What are marine protected areas? Our planet’s oceans are negatively impacted by climate change, habitat degradation, pollution, overfishing, and invasive species. To offset the impacts of these stressors, marine protected areas have been established around the world and are a cornerstone in efforts to revitalize, restore, and protect our oceans. Marine protected areas differ from other parts of the ocean because they have regulations on human activities like fishing, mining, boating, and aquaculture to protect the ecosystems within their boundaries. Our spectacular California coast contains a network of over 124 marine protected areas managed by the state, and has several larger marine protected areas called National Marine Sanctuaries managed by the federal government. The waters of Slide Ranch are managed by the Greater Farallones National Marine Sanctuary.
What are invasive species? Invasive species are organisms introduced to an ecosystem where they do not naturally or historically occur. Invaders can have far-reaching impacts on native species, such as outcompeting them for resources like food. Compared to a lot of other parts of the world, California has many invasive species, especially in and around San Francisco Bay.
What am I researching and why does it matter? Early on in my master’s program I began to think about if and how marine protected areas could be used as a tool to prevent invasive species from causing harm to an ecosystem. After diving into the scientific literature, I realized that few studies examined this relationship, and those that do offer competing sides of the story, with some suggesting they may provide resilience against invasive species and others proposing they don’t. This led me think about how the relationship between invasive species and marine protected areas may look on our coast that has both an incredible network of marine protected areas and a lot of invasive species. Although the vast majority of invaders are in bays and harbors, many marine protected areas are located adjacent to these areas that may serve as possible sources for invaders to establish in protected areas. Ultimately, this is the question at the heart of my current research project.
The tremendously biodiverse intertidal at Slide Ranch serves as one of 10 sites in my research project where I am conducting surveys for invasive species in marine protected areas from Bolinas to Pacific Grove. Slide Ranch is included in my study because it has been surveyed in the past by members of my lab at the Smithsonian Environmental Research Center who found Watersipora, an invasive colonial organism belonging to a group of invertebrate animals called Bryozoans (pictured below). I wanted to return to this site to see how the abundance of this organism may have changed over time and determine whether there were any arrivals of additional invaders.
Effectively managing protected areas requires a comprehensive understanding of what species inhabit them, and this should include efforts to document invasive species, which are becoming an increasingly powerful threat to native ecosystems. As marine protected areas become a more common tool for conservation, including on our coast in California, understanding how they are performing and can be used to protect our oceans is critical.
About Maggie: Maggie Stoffer is a master’s student at San Francisco State University and at the Smithsonian Environmental Research Center Marine Invasions Lab. Maggie also teaches in San Francisco State’s Department of Biology. Maggie earned their B.A. in Biological Sciences at Smith College in 2023. They are passionate about science communication, increasing accessibility in science, and conducting research with meaningful conservation outcomes. In their free time, Maggie enjoys cooking, hiking, and spending time with their dog Mackerel.
