Marine chemistry, also known as ocean chemistry or chemical oceanography, is the study of chemical content in marine environments as influenced by plate tectonics and seafloor spreading, turbidity, currents, sediments, pH levels, atmospheric constituents, metamorphic activity, and ecology. Marine life has adapted to the chemistries unique to Earth's oceans, and marine ecosystems are sensitive to changes in ocean chemistry.
The impact of human activity on the chemistry of the Earths oceans has increased over time, with pollution from industry and various land-use practices significantly affecting the oceans. Moreover, increasing levels of carbon dioxide in the Earths atmosphere have led to ocean acidification, which has negative effects on marine ecosystems. The international community has agreed that restoring the chemistry of the oceans is a priority, and efforts toward this goal are tracked as part of Sustainable Development Goal 14.
Chemical oceanography is the study of the chemistry of Earth's oceans. An interdisciplinary field, chemical oceanographers study the distributions and reactions of both naturally occurring and anthropogenic chemicals from molecular to global scales.
Due to the interrelatedness of the ocean, chemical oceanographers frequently work on problems relevant to physical oceanography, geology and geochemistry, biology and biochemistry, and atmospheric science. Many chemical oceanographers investigate biogeochemical cycles, and the marine carbon cycle in particular attracts significant interest due to its role in carbon sequestration and ocean acidification. Other major topics of interest include analytical chemistry of the oceans, marine pollution, and anthropogenic climate change.