623 



RECOMMENDATIONS CONCERNING CHEMICAL rACTORS 



Research preserves 



Because of the enormous complexity of the physical, chemical, and 

 biological interactions in marine ecosystems, there should be a sys- 

 tem of ecological classification of natural coastal systems that can be 

 used to make first approximations of the impact of specific types of 

 wastes on them. Such classifications may require new geochemical 

 surveys of coastal systems, but in large part could be erected from 

 extant knowledge. 



The classification of coastal systems should be used to select and set 

 aside type preserves for experimental use, for such purposes as stress- 

 ing the environment to determine the effects of the stress and the rate 

 of recovery of the system when the stress is removed. Such study 

 areas would allow the carrying out of experiments that might not be 

 permissible in areas not so set aside, and would prevent the intrusion 

 of other human influences. The stresses applied might include the ad- 

 dition of growth-suppressing substances, nutrient substances, heat, etc. 

 The study areas would be provided with adequate laboratory facili- 

 ties for intensive investigation and manipulation. 



Type systems to be set aside should include tropical, temperate, and 

 boreal systems, and would include open coastal areas, salt marsh es- 

 tuaries, tidal estuaries, salt-wedge estuaries, mangrove swamps, and 

 fjords. They should encompass systems of varying depths, sizes, and 

 geomorphology to permit the collection of data to construct models 

 useful for coastal waste management. We consider this to be a matter 

 requiring irmnediate attention. 



Chemical processes involving dissolved inorganic constituents 



(1) The concentrations and the forms of trace elements believed 

 to be biologically significant in the wat^-rs and sediments and their 

 concentrations in organisms in different areas should be determined. 

 The forms in which these elements occur affect their availability to 

 organisms. Areas that should be examined are near the mouths of 

 large rivers and coastal areas where fresh water inputs come pri- 

 marily from waste water discharges. The elements of concern would 

 probably include but not be limited to copper, zinc, cobalt, chromium, 

 arsenic, molybdenum, selenium, mercury, cadmium, and lead. 



(2) The degree of complexing of trace metals by the organic and 

 inorganic constituents of wastewater effluents, sea water, and estuarine 

 waters should be evaluated in both laboratory and field studies. Tem- 

 perature ranges in the natural environment as well as in the vicinity 

 of thermal outfalls should be represented in the experimental pro- 

 gram. Not only may the degree of complexing prove significant in con- 

 trolling the behavior of the metal ions, it may be pertinent in un- 

 derstanding the action of organic residues. The forms in which the 

 metals exist are important factors in their biological activity. 



Chemistry of particles and pi^ocesses in sediments 



(1) Experiments should be carried out to establish the effects on 

 soluble components, particularly waste solutes, of flocculation, ag- 

 gregation, coprecipitation, and sorption. A study should be made of 

 the physical-chemical factors and the role of organisms in affecting 



