Skip to content

Aquatic Photochemistry

at Woods Hole Oceanographic Institution

Research Projects

Crude Oil

Sunlight alters the physical and chemical properties of crude oil spilled at sea. These alterations to oil properties impact the fate, transport, and efficacy of chemical agents used to clean up spilled oil.

Dissolved Organic Matter

Sunlight can completely oxidize DOM into CO2, a greenhouse gas, and partially alter DOM into new compounds. These alterations impact the lability of DOM to microbes. Most of our DOM work focuses on permafrost DOM draining arctic soils.


Plastics are an emerging pollutant. We want to understand how long plastics last in the environment. To do so, we characterize the rates, pathways, and products of plastic degradation.

Instrument Development

We’re building a system that can measure rates of photochemical oxidation, microbial respiration, and photosynthesis in the water column.

The Ward Lab

Our facility is housed in Fye Laboratory as part of the Marine Chemistry and Geochemistry Department at WHOI.  We are broadly interested in characterizing the rates and pathways of organic carbon degradation in aquatic ecosystems. We study lots of different types of organic carbon, including naturally derived organic carbon, like dissolved organic matter, and anthropogenic contaminants, like crude oil and plastics.

Selected Publications

  • Bowen, J.C., Ward, C.P., Kling, G.W., & Cory, R.M.Arctic amplification of global warming strengthened by sunlight oxidation of permafrost carbon to CO2. In Press at Geophysical Research Letters.
  • Ward, C.P. & ­Reddy, C.M. We need better data about the environmental persistence of plastic goods. In Press at Proceedings of the National Academies of Sciences.
  • Ward, C.P. & Overton, E.B. How the 2010 Deepwater Horizon spill reshaped our understanding of crude oil photochemical weathering at sea: a past, present, and future perspective. 2020. Environmental Sciences: Processes & Impacts. 22, 1125-1138.
  • Ward, C.P., Armstrong, C.J., Walsh, A.N., Jackson, J.J. & Reddy, C.M. Sunlight converts polystyrene into carbon dioxide and dissolved organic carbon. 2019. Environmental Science & Technology Letters. 6 (11), 669-674.
  • Ward, C.P., Sharpless, C.M., Valentine, D.L., Aeppli, C., Sutherland, K.M., Wankel, S.D. & Reddy, C.M. Oxygen isotopes (δ18O) trace photochemical hydrocarbon oxidation at the sea surface. 2019. Geophysical Research Letters, 12, 6745-6754.
  • Ward, C. P., Armstrong, C. J., Conmy, R. N., French-McCay, D. P., & Reddy, C. M. Photochemical Oxidation of Oil Reduced the Effectiveness of Aerial Dispersants Applied in Response to the Deepwater Horizon Spill. 2018. Environmental Science & Technology Letters, 5, 226-231.
  • Ward, C.P., Sharpless, C.M., Aeppli, C., French-McCay, D.P., Valentine, D.L., Rodgers, R. P., Gosselin, K.M., Nelson, R.K., & Reddy, C.M. Partial photochemical oxidation was a dominant fate of Deepwater Horizon surface oil. 2018. Environmental Science & Technology, 52 (4), 1797-1805.