Renee Takesue is a marine geochemist for the Pacific Coastal and Marine Science Center of the US Geological Survey (USGS). “Geochemistry is a field that combines chemistry and geology. The chemistry of earth materials—such as rocks, soil, and water—can tell us a lot about the environments in which they were formed, or about natural processes and human activities that affect them. Geochemistry also includes chemicals that are added to the environment by humans and can harm ecosystems (contaminants).”

Renee has had a fascination with the ocean since she was very little. She grew up in California near the coast, and she remembers having fun on the weekends exploring tidepools. Summer vacations to visit family in Hawaii furthered her curiosity about the ocean and what lives in it. “We harvested limpets and seaweed and used a throw-net to catch reef fish, which we cooked and ate right on the beach.” After taking a harbor cruise as part of a class in school, she was hooked. The teachers had the kids make plankton nets from pantyhose and baby-food jars and dredge up sea creatures and samples of the bottom. “I had the time of my life and knew then that I wanted to be a marine scientist.”

With this career in mind as she was applying to colleges, Renee selected a university that offered majors in oceanography and geology. In college, she took advantage of every opportunity to get hands-on experience and learn new skills by working in labs or on research projects. This sort of experience was equivalent to an internship in other disciplines and proved especially valuable when she was applying to graduate schools.

Renee explained that to get a job as a researcher in oceanography and other marine science fields, most people need a doctorate (PhD). Advanced studies in marine science “teach you how to identify complex scientific issues and carry out strategies to investigate them.” Renee continued in school until she earned a PhD in chemical oceanography. For those who are interested in the subject, but who might not be able to pursue a PhD, she says there are plenty of technical careers in marine geochemistry that only require a bachelor’s or master’s degree. A lot of those jobs involve studying, monitoring, and regulating water quality and other environmental concerns.

In Monterey Bay National Marine Sanctuary

Black carbon from wildfires on a beach in Monterey Bay National Marine Sanctuary after the “first flush,” the first big storm of 2021 that washed material out to the coastal ocean.

Most of her research for the USGS focuses on coastal areas and their watersheds, which is where the majority of the population on the West Coast lives and where contaminants originate. “Geochemistry is a versatile field. I work in a wide range of environments, from glacier-carved beaches where urban pollutants threaten salmon and orca, to tropical coral reefs where coastal development leads to harmful runoff, to marshes being restored for wildlife but whose below-ground sediment contains potentially toxic metals from historic gold mining. Recently, environmental quality after the California wildfires has become a concern for both wildlife and humans. I characterize contaminants in wildfire materials and potential health risks for coastal communities.”

Renee feels lucky to have a job that is both so interesting to her and so important to the world at large. “I get to work on issues that are national priorities and directly benefit society. The ocean is critical to our well-being, so keeping it clean and allowing natural, self-sustaining flows of sediment and water will benefit society for generations.

Collect Sediment From The Seafloor


This photo is from 2012, where Renee and a colleague are preparing to collect sediment from the seafloor in San Francisco Bay using a clamshell-style bottom sediment sampler. Today, she spends less of her time in the field. “

As a mid-career researcher, I spend most of my time in the office planning projects and budgets, analyzing data, writing scientific publications, developing partnerships, and managing USGS staff and labs. Less than 10% of my time is spent collecting new data in the field and doing analyses in the lab. This is very different from early in my career when I spent the majority of my time outside in the field followed up by work in a lab. Now my technicians get to do these fun tasks.” — Renee Takesue, USGS

Did You Know?

Ship Worm Clam

Damage to wood by the shipworm clam was often extensive enough to sink a ship!

As a tiny larva floating in the ocean, the clam lands on the hull or piling of a ship and immediately begins to grind into the surface of the wood with its shells.

How did Christopher Columbus and other mariners protect their ships from the shipworm?

Learn more at Ship “Worm” Clam