[2] She was a strong advocate for environmental protection, credited with helping pass legislation expanding the boundaries of Northern California's Gulf of the Farallones and Cordell Bank national sanctuaries, increasing the area of federally-protected coastal waters.

[8] Another study Williams performed in collaboration with Indonesian scientists looked into ways to restore seagrass beds, endangered habitats that are important for, among other things, supporting fisheries and protecting coastlines.

[12] Her connection with political activism began early in her scientific career; in 1993, she was appointed to a panel of scientists consulting with the assistant secretary of the Interior, and in 2000 she received an Aldo Leopold Fellowship in Environmental Leadership.

[5] This activism continued to the end; mere weeks before her death she co-wrote an article commemorating the one-year anniversary of 2017's March for Science in which she urged scientists to become more engaged with the public and politicians.

[13][14] Williams also used her scientific work to speak out about the dangers of climate change; in 2010, she helped raise the alarm that even small increases in ocean temperature could rapidly accelerate the growth of invasive species in marine environments.