SECTION 1. INTRODUCTION 



The potential of the carbon cycle of the sea to either yield fish or 

 store atmospheric C0 ? is a subject of continuing controversy as man's 

 ability to modify the marine environment increases. Because the actual 

 amount of CO- fixed annually during marine photosynthesis is unknown, 

 the fates of phytoplankton, serving as a precursor either to fish carbon 

 or to sediment carbon, are also unknown. Debates over the amount of 

 potential fish harvest (Ryther, 1969, Alversen et. al., 1970) and CO^ 

 storage capacity (Broecker et. al., 1979; Walsh et. al., 1981) of the 

 ocean thus hinge on the amount and fate of marine primary production. 

 Current estimates of annual marine primary production range from 20 to 



Q 



55 x 10 tons of carbon per year (Ryther, 1969; Piatt and Subba Rao, 1975; 

 DeVooys, 1979; Walsh, 1981). This range accounts for =25 to 50 percent of 

 the total net global carbon fixation (Woodwell et. al., 1978), and is 400 

 to 1000 percent of either present fish yield or fossil fuel emissions. 



Over the last century, man's ability to extract nitrogen from the atmo- 

 sphere has also begun to rival that of N ? fixation by plants. Between 

 1950 and 1975 world production of agricultural fertilizers increased 

 ten-fold. Nitrogen loadings from agrarian runoff, deforestation, and 

 urban sewage have already impacted local streams and ponds, some large 

 lakes, major rivers, and perhaps even the continental shelves. Nitrogen 

 is now only routinely measured in 25 percent of the world's 240 largest 

 rivers, however, and few biological time series are available to docu- 

 ment the coastal zone's past response to fluvial nutrient transients on 

 a decadal time scale. The annual primary production of the Dutch 

 Waddensea, for example, has apparently increased threefold between 1950 

 and 1970 (Postma, 1978). Future measurements of ocean color by satel- 

 lites and of jn situ fluorescence by buoys are required to provide ade- 

 quate chlorophyll time series to assess the fate of phytoplankton carbon 

 and nitrogen, as well as their productivity in the sea. With this 

 information, one can address present problems of overfishing, as well as 

 the future and perhaps more ominous consequences of these linked 



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