Shaping Science: An Interview with Rachel Ridgway

Physical Sciences division instructor talks about her inspirations, research work


billandkent/ Creative Commons

Rachel Carson National Wildlife Refuge was established in 1966 in cooperation with the State of Maine to protect valuable salt marshes. Carson was a world-renowned marine biologist.

This year Glendale Community College featured a robust schedule of events during Women’s History Month under the banner, “Nevertheless She Persisted: Honoring Women Who Fight All Forms of Discrimination Against Women.” The contributions of women in various areas of society were recognized, including science, comedy, documentary film, literature, and politics.

GCC’s Rachel Ridgway, from the college’s Physical Science division, lectured about how women have helped to shape environmental policy. She recently sat down with El Vaquero to share some insights.

What do you love about studying geology?

The breadth of knowledge that geology encompasses never ceases to amaze me. Aside from the pure sciences of physics and chemistry, geology involves astronomy, geography, hydrology, meteorology, biology and all of the sub-disciplines where these overlap with one another.

Hydrogeology is my specialty, but the complexity of our climate system and all its feedback systems also fascinates.

What do you love about teaching geology and oceanography?

That moment when someone has made a new connection, understanding their relationship with our world in a deeper way. Sometimes it’s captured in wide-eyed wonder, other times with a particularly apt question or observation, or a new confidence in explaining an idea.

I love to watch my students develop confidence in their abilities as problem solvers. I love introducing them to their inner scientist and helping them grow their empirical minds.

Can you describe your graduate school experience at CSULA?

My advisor, Dr. Barry Hibbs, introduced me to the relevant literature and helped me learn what to look for in the field. Field work was always fun, demanding long hours schlepping gear and collecting water samples with my fellow lab mates.

As field research neared its end, I assembled all the data into a cohesive thesis. It was really satisfying to see all our hard work come together to tell a meaningful story that would help inform policy in the watershed.

What are the challenges of doing research?

Field research requires advance planning. First there’s reconnaissance. Then, when it’s time to actually go out and collect the data, you have to bring all necessary supplies. If you forget something, or something breaks, then you have to improvise. It’s a fun, and sometimes frustrating, challenge. In environmental research you are subject to the whims of the weather. It doesn’t matter if it’s -17°F or 120°F, the work still has to get done.

What is bioaccumulation?

Bioaccumulation is the tendency for certain elements or compounds to become more concentrated in biological tissue as you move higher up the food chain. It happens because some things bind to tissue rather than being excreted. So when an organism gets eaten, whatever elements or compounds are bound to its tissues, gets passed along to the eater.

When that eater gets eaten, the process continues. Things that bioaccumulate tend to be liphophillic, meaning they bind to fatty tissue. Sometimes they also bind to proteins. 

Probably the most egregious case of bioaccumulation occurred in Minamata, Japan in the mid-20th century due to industrial mercury pollution.

When methyl mercury builds up in mammalian tissue it causes a variety of neurological impacts. Other chemicals can bioaccumulate including lead, selenium, cadmium, DDT and other synthetic pesticides.

What is the legacy of Rachel Carson?

Rachel Carson is one of my personal heroes. She was a marine biologist and nature writer who documented the detrimental impacts of widespread use of the pesticide DDT, most notably the disappearance of top level avian predators.

Her seminal work “Silent Spring,” published in 1962, led to DDT being banned in the U.S. in 1972. She was one of the first environmental scientists.

Her work helped to galvanize the environmental movement that pushed for regulations to protect our environment – a movement which continues to the present day as we struggle to address the impacts of global climate change and its causes.

Describe your work in the Upper Newport Bay estuary.

Our work examined the sources of selenium to Upper Newport Bay, a protected ecological preserve. Selenium tends to bioaccumulate, reducing the viability of bird and fish populations.

We found that naturally-occurring selenium bound in historic marsh sediments was being remobilized by a change in redox chemistry resulting from the drainage of the marsh.

Today, oxygen and nitrate dissolved in shallow ground water react with the chemically reduced selenium to form highly soluble selenium oxyanions. We identified several selenium hot spots, where shallow selenium-rich ground water discharged into surface streams and ultimately into Upper Newport Bay. 

How did your research help to inform policy at the Santa Ana Water Board in April 2017?

The selenium hot spots that we documented helped to inform the implementation of Best Management Practices (BMP’s) to reduce selenium loading to surface streams from shallow ground water discharge. The Board continues to consider the best approach for managing this diffuse source of selenium pollution, most recently looking into the feasibility of sending discharge from the most contaminated ground water sources to the sanitary sewer system.

They are still in the process of adopting Total Maximum Daily Loads (TMDL’s) and appropriate monitoring protocols to protect wildlife. Science makes slow and steady progress.

The regulatory process moves ever more slowly in its wake.

Tell us about publishing your work in the Water Research and Education Journal in September 2017?

This paper expanded on work that began with Dr. Barry Hibbs and one of his former graduate students, Monica Lee, back in 2004. They formulated the hypothesis that selenium was being remobilized from historic marsh sediments.

This paper gives additional support to this interpretation using selenium speciation analysis in water and soil samples.

What are your current research goals?

Currently, I am in the initial stages of reconnaissance and literature review to support the development of student research at GCC. I have a couple of projects in mind: one that will look at the fate of styrene on Southern California beaches and another to consider potential impacts of expanding the Scholl Canyon landfill. I am also working on another paper with Dr. Hibbs that will help constrain sources of ground water recharge to the shallow aquifer in the San Diego Creek watershed.

What advice do you have for students studying science?

If you want to study science, the best classroom is the field.  Find as many scientists as you can, and talk to them about their work and how they got where they are. Always be on the lookout for opportunity.

When it comes, take it. Keep in mind that the more you learn, the more you will realize that you really don’t know very much. But keep questioning. That’s the key. And keep seeking answers. [Students also need to know that] you don’t have to be a “math genius” [to study science], but you do have to recognize that the way through the problem is in the problem.

And you have to know to ask if you need help. No one does science alone. It is a highly collaborative process.

The only stupid question is the one you didn’t ask. Stay curious.


Nare Garibyan can be reached at [email protected]