Practical application of any of these possible indexes requires that we be 

 able to make the backward (to discharges) and forward (to angling decisions) 

 links. An initial reconnaissance of the literature on pollution effects on 

 marine fishes has convinced us that the backward link will at least be very 

 difficult. With the exception of laboratory studies of acute toxicity using a 

 variety of elements and compounds and many different fishes , there seems to be 

 remarkably little systematic quantitative understanding of how pollution of 

 natural saltwater effects the availability of fishes of different species, or 

 of how it affects population numbers and size distributions. 



In table 3 we summarize the findings of our survey to emphasize for the 

 reader the paucity of pollution-related information (that on suspended solids) 

 relative to that on temperature and salinity tolerances. Further, the information 

 we were able to find on dissolved oxygen tolerances — the single most important 

 pollution-related water quality measure for our freshwater work — is confined to 

 a few studies, too varied in methods and results to permit meaningful comparisons .-* 



Thus, unless further searching can improve our data base in this key area, 

 it appears we cannot make the backward link using models of pollution discharge 

 dispersion, dilution, and transformation as the bases for predicting fish 

 availability or quality measures. This will be especially unfortunate because 

 we do anticipate having available at RFF a coastal county discharge inventory, 

 complete for the lower 48 states, and reflecting point and nonpoint sources, 

 including the inflow of pollution loads in freshwater streams." It will be 

 possible to project how these loads will change with implementation of the 

 clean water legislation of 1972 and 1977. 



In terms of the link forward to angling decisions, the species type, 

 prospective bag, and ecosystem effects are all defensible as influences on 

 participation decisions. However, to use any of these indices it will be 

 necessary that it match the available data on participation. That is, differential 

 levels of participation across measurement units must be tied to differential 

 values of the chosen index(es). For example, to our knowledge the best 

 available data on participation in saltwater angling identifies individuals no 

 more finely than by state of residence.' In order to test the effect of an 



5 We found DO references for Atlantic cod (Wise 1961, and Davis 1975); 

 American eel (Usui 1974); Atlantic herring (Dorfman and Westman 1970); white 

 perch (Dorfman and Westman 1970); shad (Chittenden 1973, Hoff et al. 1966); 

 striped bass (Chittenden 1971, Dorfman and Westman 1970); and tuna (Dizon 1977). 



" The inventory is being developed as part of the Strategic Assessment 

 Project of the Office of Resource Coordination and Assessment of the National 

 Oceanic and Atmospheric Administration. This project also involves the generation 

 of maps showing areas of critical importance in the life cycles of numerous 

 coastal fishes (fin and shell) and it may be possible that by combining inventory 

 and maps we can produce a useful mixed (quantitative and qualitative) model. See 

 Ehler et al. n.d. 



' This is the nature of the data from the 1975 National Survey of Hunting, 

 Fishing, and Wildlife-Associated Recreation, NSHFWR (U.S. Department of the 

 Interior n.d.). 



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