I am a geoscientist, more specifically, an oceanographer.  My research and teaching concentrates on chemical oceanography, climate change science, and isotope geochemistry, and my scientific investigations are found at the intersection of these three fields.  My laboratory specifically investigates the (bio)chemical properties of seawater and how they influence the ocean’s ability to be both a source as well as sink of greenhouse gases.  Methane and carbon dioxide have been the focus of our investigations where we seek to uncover their controlling dynamics in the ocean.  The ocean is a massive reservoir of both of these gases, and research in my laboratory focuses on the climatological feedbacks and geochemical processes that can lead to their increased emission, as well as removal.  In addition, we investigate how the biochemical dynamics of these gases influence seawater chemistry, such as dissolved oxygen, nutrient, trace metal, and pH distributions.  Since our investigations are conducted in both the laboratory as well as at sea, we routinely develop new instrumentation required for shipboard chemical analyses.  


Our laboratory takes a 3-pronged approach to research.

  1. At sea, we collect data and samples to characterize natural oceanographic chemical distributions.  This information is used to constrain sources, sinks, and biogeochemical processes.  
  2. We simulate natural biogeochemical processes in the lab.  Since the ocean is an extremely multivariable and often inaccessible environment, simulating ocean biogeochemical processes in the lab enables us to control many of these variables and collect higher resolution data.  
  3. We develop new instruments and methods which enable more sensitive, precise, rapid, and/or automated measurements at sea and in the lab.


  • Chemical Oceanography
  • Climate Science
  • Isotope biogeochemistry


  • Measuring sources and sinks of greenhouse gases in oceanic and freshwater environments.
  • Uncovering processes that can enhance or diminish these emissions.
  • Quantifying chemical oceanographic changes caused by variations in oceanic greenhouse gas dynamics.

Research in my laboratory focuses on oceanic methane and carbon dioxide isotope biogeochemical investigations. Our projects are heavily rooted in analytical chemistry, while also being very multidisciplinary drawing from the fields of geology, chemistry, biology, physics, mathematics, and engineering. I am always interesting in talking with intelligent, enthusiastic, and hardworking students about the possibility of joining our team. I encourage prospective Master’s of Science and Ph.D. students to contact me directly before submitting an application to our graduate program.  I also strongly encourage interested undergraduates to contact me about conducting independent research in our laboratory.

Email: john.kessler@rochester.edu