By Anastasia G. Ennis, Graduate Student Researcher in the Cohen Lab at the Romberg Tiburon Center for Environmental Studies, San Francisco State University
If you travelled back in time 200 years or more, the San Francisco Bay Area would look very different. In the time before Europeans settled on the shores of this amazing estuary, rolling hills, meandering creeks, and broad marshes supported a unique assemblage of wildlife and a much smaller human population. Today, the Bay Area is a bustling population center, home to almost 8 million people. Fortunately, thanks to several far-sighted community leaders, we can still see fragments of the natural landscape that once was, including tidal marsh tracts along many edges of the bay.
Tidal marsh represents the vital transition zone between land and water. In the years following the Gold Rush
, though, marshes were considered a smelly, muddy, mosquito
-infested waste of prime shorefront property. Many marshes were filled or diked and converted to agriculture, shipyards, duck ponds, or salt production facilities
. Over 80% of the region’s tidal marsh was lost, reducing habitat for species uniquely adapted to life at the water’s edge, including the now-endangered salt marsh harvest mouse (SMHM)
The SMHM is the only mammal species in the world endemic to tidal marshes.* It also happens to be endemic to the salt and brackish marshes surrounding the San Francisco Bay. I find the SMHM to be especially charismatic, not only because it’s adorable but also because we share some things in common: I’m also a mammal native to the San Francisco Bay Area and, like the mouse, I enjoy swimming. This affinity was part of the reason I chose to study SMHM genetics for my Master’s thesis at San Francisco State University.