The ocean has been referred to as a "chemical soup" because it contains many chemical compounds, elements, gases, minerals, and organic and particulate matter. While water is the most plentiful ingredient, salts are among the most important. Amazingly, despite the major changes that have taken place on Earth throughout history -- continental collisions, land formations, glaciation -- the basic composition of seawater has remained relatively constant for millions of years.
Chemical oceanographers, also called marine chemists, marine geochemists, or even marine biogeochemists, may study one or a combination of the following: formation of seawater and seafloor sediments, relationships between chemical compounds (both organic and inorganic), how chemical inputs to the ocean (including pollution) affect it, and how the chemistry of the ocean affects or is affected by biological, geological, and physical factors. As with the other disciplines of oceanography, chemical oceanographers rely on and interact with researchers from the other disciplines.
One important aspect of chemical oceanography is the study of pollutants. This work may lead chemical oceanographers to the deep ocean, coastal bays and estuaries, or inland rivers, streams, and lakes. Sources of pollutants range from the obvious (sewage, oil or fuels, ocean dumping) to sources that are harder to detect or trace (agricultural or lawn runoff containing chemical fertilizers, leaking septic systems, road runoff, or storm drain overflows). Chemical oceanographers study the impact of such pollutants by examining how they interact with seawater, marine life, and sediments. Chemicals and pollutants introduced to a marine environment may behave very differently depending on environmental conditions such as salinity, wind, rainfall, temperature, and transport methods. Transport methods include land-based (for example, surface runoff or groundwater), water-based (rivers and streams), and atmosphere-based (rain and dust).
The study of carbon and its role in global climate change has captured the attention of chemical oceanographers for decades. Since the industrialization of the 18th century, researchers estimate that the amount of carbon dioxide in the atmosphere has increased by 25 percent. Although the scientific debate continues over whether the increase in atmospheric carbon dioxide has caused global warming or vice versa, it is generally accepted that modern society has added to the amount of carbon dioxide in the atmosphere.
What does all this mean? Since carbon dioxide absorbs infrared radiation (heat), an increase in carbon dioxide in the atmosphere would keep the heat from escaping into space. This would cause the Earth to warm up just as a greenhouse holds heat, thus the popular term "greenhouse effect." Chemical oceanographers are working to understand the ocean's role in this and other theories related to global climate change.
Modern society's rapid technological advances, including the development of complex chemical compounds and processes used to produce and manufacture energy, food, clothing, medicine, and other products, have created a need for chemical oceanographers. In the quest for bigger, stronger, faster, more, the costs of "improvements" often get overlooked. For example, the disposal of waste that results from products and by-products can be a problem in itself. Who would have thought that household cleaning products, fertilizers, pesticides, boat paints, and leaded fuel -- all products that saved time, worked better, and often cost less -- could have contributed to the degradation of many marine and coastal areas? Fortunately, researchers in many oceanographic disciplines and related areas, including marine chemists, have worked together to improve our understanding of such impacts, which has, in turn, led to improved controls, regulations, testing methods, and ultimately, safer products.
The work of chemical oceanographers will continue to provide answers to important questions. For example, the use of the oceans for waste disposal and as a source for drugs and minerals will require cooperative research between ocean chemists, biologists, and geologists. It is the work of marine chemists that aids ocean engineers in the development of instruments, vessels, and ocean vehicles that, in turn, improve the ability of researchers of all oceanographic disciplines to go to sea, collect data, and discover previously unknown formations, marine life, and phenomena.
As the population discovers new ways to use the oceans -- be it for food, transportation, energy, or waste disposal -- chemical oceanographers will play an important role in improving our knowledge about the impact of these activities on the ocean and its ability to sustain them.