Meet Baykeeper Senior Scientist Jon Rosenfield

Science is at the heart of Baykeeper’s work.  Our pollution investigations and water quality monitoring, analysis of proposed environmental laws, and even lawsuits to stop polluters all rely on sound science and technical understanding of the complex ecology of San Francisco Bay.

Which is why we’re happy to announce we expanded our science team! Dr. Jon Rosenfield recently joined us as our new Senior Scientist.  Jon, a conservation biologist, will help increase Baykeeper’s leadership on everything from endangered species protections to improving conditions for wildlife and commercial fisheries throughout the Bay and Delta.  

Jon says he decided to apply for the senior scientist position because of Baykeeper’s strong reputation for defending the Bay. “If you care about protecting and restoring the living diversity of the Bay estuary, as I do, there is no better place to work than Baykeeper,” he explained.

Jon first came to the Bay Area in 1991 to work for the Sierra Club Legal Defense Fund (now Earthjustice), where he fell inlove with Pacific salmon, including the Chinook and Steelhead that migrate through the Bay on their way to and from spawning grounds in the Central Valley. That experience sparked an enduring passion for fish ecology, evolution, and behavior.

Jon went on to work for The Bay Institute for over 10 years, protecting the Bay’s endangered fish and commercial fisheries and collaborating closely with Baykeeper staff during that time. He is one of the region’s leading experts on the importance of freshwater flows from the Delta for the sustainability of the Bay’s ecosystem and fish populations. 

In his free time, Jon is an enthusiastic birder and kayaker—a pastime that came up during the Baykeeper interview process when asked whether he felt comfortable conducting water quality investigations by kayak in stormy weather. “I thought to myself, ‘Are they really saying they would pay me to kayak on San Francisco Bay?’ I had to try really hard to contain my enthusiasm!”   

Jon, Maragret, and Mike

Above: Jon Rosenfield (left) with No Coal in Oakland’s Ms. Margaret Gordon (center), and Baykeeper founder Mike Herz at the 2019 Baykeeper Dinner.