Analytical Chemistry in Oceanography zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJ Kenneth S. Johnson', Kenneth H. Coale, and Hans zyxwvutsr W. Jannasch2 Moss zyxwvutsrqponm Landing Marine Laboratories P.O. Box 450 Moss Landing, CA 95039 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA z 0 zyxwvutsrqpon 2 I B 6 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHGFEDCBA Chemical measurements in the ocean involve a unique set of challenges re- lated to the distinctive composition of seawater, the large spatial and temporal scales over which measure - ments are made, and the frequent need to perform analyses while at sea under difficult conditions. These problems are not familiar to many analytical chemists, in part because it is unusual to find chemical ocean- ographers or geochemists in close contact with their chemistry col- leagues (I). Chemical oceanography has been practiced primarily in departments or institutions oriented toward ma- rine or environmental sciences. Our chemical understanding of the oceans is, however, directly linked to the development of the latest analyt- ical tools and advances in chemistry and engineering. A report soon to be issued by the National Research Council states that a significant in- crease is needed in our abilities to observe ocean chemistry and to study the biological, physical, and chemical (biogeochemical) proceqses that con- trol the flow of chemicals through the ocean and its linkage with the atmo- sphere (2). Rapid improvements in the methods of chemical analysis available to oceanographers are needed, particularly with respect to sensors that can operate in situ and unattended for long periods of time on deep-sea moorings. These ad- vances will require much closer coop - eration between the analytical chem- istry and chemical oceanography communities. Increasing attention has been fo- cused on ocean chemistry because of civilization's impact on the flow of chemicals through the sea. On a local scale, nutrient loading from sources 0003 -2700/92/0364-1065A/$03.00/0 0 1992 American Chemical Society such as sewage plants or runoff from farmland (e.g., ammonia, nitrates, and phosphates) can lead to in- creased rates of plant production, or eutrophication, in surface waters. Eutrophication is linked to toxic phy- toplankton blooms (e.g., red tides) and greater oxygen demand in the subsurface waters. Increasing anoxia in the water column attributable to eutrophication has had a negative impact on marine resources in both the New York Bight (3) and the Chesapeake Bay zyxwvu (4). A single episode of anoxia in the New York Bight re- sulted in a $60 million loss to surf- clam fishery alone (3). In many cases, the impacts of these perturbations are not recognized or understood be- cause we lack records of natural chemical variability in the marine environment or an adequate means to monitor it (5). On a global scale, the flow of chem- icals through the ocean system is closely linked to the Earth's climate. The ocean holds 60 times more inor- ganic carbon than does the atmo- sphere, and perturbations in the flow of CO, through the ocean are related to changes in atmospheric CO, and global temperature (6). Release of CO, from the burning of fossil fuels, which has resulted in a 30% increase in atmospheric CO, since 1850, has the potential to produce even greater climatic changes than were experi- enced over the last glacial cycle (7). Much of this CO, will enter the ocean, but the rates of CO, absorp- tion in seawater are not yet well known (8). Rapid changes in ocean circulation may produce large CO, fluxes between the ocean and the at- mosphere (9); small changes in ocean chemistry may also draw large amounts of CO, from the atmosphere and regulate climate (IO). Despite the importance of these cy- 'Also affiliated with Monterey Bay Aquarium Research Institute, 160 Central Ave., Pacific Grove, CA 95039 'Present address: Monterey Bay Aquarium Re- search Institute i 1 ANALYTICAL CHEMISTRY, VOL. 64, NO. 22, NOVEMBER 15,1992 1065 A