Environmental Quality Program 



This program is designed to provide information on the 

 quality of the oceanic environment and to assess and predict 

 man's impact on this environment through research in geo- 

 chemical processes and marine pollution. The present program 

 consists of four major investigations: the Geochemical Ocean 

 Sections Study (GEOSECS), which is concerned with detailed 

 measurement of physical and chemical characteristics of ocean 

 waters along Arctic to Antarctic sections; the Pollutant Trans- 

 fer Program, which involves investigations of mechanisms and 

 pathways by which pollutants are transported to and within 

 the oceans; the Biological Effects Program, which assesses the 

 impact of selected pollutants on marine organisms; and the 

 controlled Ecosystem Pollution Experiment (CEPEX), which 

 is providing information about the effects of pollutants on 

 pelagic communities contained in large plastic enclosures. 



Geochemical Ocean Sections 

 (GEOSECS) Study 



GEOSECS is an international cooperative program in- 

 volving geochemists from 14 United States universities. In- 

 vestigators from Belgium, Canada, France, Germany, India, 

 Japan, and the United Kingdom are also participating in 

 GEOSECS or are carrying out similar programs coordinated 

 by the United States. The U.S. program involved the occupa- 

 tion of 121 oceanographic stations in the Atlantic and 147 

 stations in the Pacific. These stations were located along north- 

 south survey tracks and generally coincided with the paths of 

 bottom-water currents. Samples of water and suspended mate- 

 rials collected at these stations and selected depths are being 

 analyzed for approximately 40 physical and chemical param- 

 eters, including temperature, salinity, pH, alkalinity, Pco2, 

 dissolved and trace gases, nutrients, trace metals, dissolved 

 and particulate organic and inorganic matter, natural radio- 

 nuclides, manmade radionuclides, and stable isotopes. 



The data are being used to determine the stirring and 

 reaction processes in the deep sea, the interchange of material 

 between deep and surface waters, and the exchange of water 

 and gases with the atmosphere. The data provide a baseline for 

 measuring amounts of pollutants, specifically nuclear and waste 

 products, that are being introduced into the ocean. Projects 

 in this program are listed in table 1. 



GEOSECS scientists have found that radioactive chemical 

 tracers can provide information about large-scale ocean mixing 

 patterns and rates of water movement. One of the manmade 

 radionuclides, tritium, was released in Arctic waters and is 

 being tracked by the scientists in bottom water formed in this 

 part of the world (fig. 1). To a lesser extent, added radiocar- 

 bon follows a similar distribution pattern, but this material 

 shows predominant accumulation in the midlatitudes (fig. 2). 



By measuring a short-lived natural radioactive component 

 of dissolved matter in seawater, like Ra--'' and Rn---, GEOSECS 

 scientists have derived Kv, the eddy diffusivity (fig, 3). Kv 

 measures the rate at which dissolved material is transported 

 across a concentration gradient. When the density structure 

 (measured as a buoyancy gradient) of different water masses 

 was plotted against Kv, a trend was obtained (fig. 3) that can 

 be used for predicting the mixing properties of any water mass 

 once its density structure is known. 



GEOSECS scientists have developed vertical transport 

 models based on evidence that fecal pellets from zooplankters 

 and small fish, along with clays, appear to scavenge from sea- 

 water soluble constituents, such as heavy metals. Although more 

 data are required to properly test the models for the scavenging 

 process, statistical use of these models in deep water has dem- 

 onstrated significant differences in the particle-assisted settling 

 rates for copper, antimony, and scandium as compared with 

 nickel, for which no scavenging is indicated. 



In the western basin of the Atlantic Ocean, GEOSECS 

 scientists have identified three major water types by their con- 

 centration of dissolved oxygen and dissolved nitrate. Bacterial 

 decomposition of organic matter in the ocean results in a de- 

 crease in dissolved oxygen and a simultaneous increase in dis- 

 solved nitrate. Almost all of this organic matter can be simu- 

 lated by a simple five-to-six carbon amino acid, requiring nine 

 molecules of oxygen to completely oxidize the molecule to COj, 

 N:.0.„ and H,0. Because the loss of nine molecules of oxygen 

 from the water always results in a gain of an atom of nitrogen 

 during respiration (or the reverse process for photosynthesis), 

 the quantity | Oj -I- 9 NO" :.] is conserved during these biologi- 

 cal changes. 



GEOSECS Data 



The GEOSECS operation group at the Scripps Institution 

 of Oceanography (SIO) has established a central data process- 

 ing facility. This facility is presently producing special data 

 reports for GEOSECS investigators and preparing a final data 

 report of shipboard analysis and several detailed chemical 

 oceanographic atlases. Laboratories have completed some anal- 

 yses and have forwarded these data to SIO (table 2). Anal- 

 yses of the remaining Atlantic and Pacific samples are being 

 completed. 



