Table 2. — Fishery Types as Determined by Water Quality Using Nielsen's Rules 



Exogenous ly Determined Water Quality Conditions 



Cold Water 

 Temperature < 18°C 



Warm Water 

 Temperature Between 

 18°C and 32°C 



Water Quality 

 Improvements 

 Traced to Policy 



Low Solids 



Water 



TSS < 100 mg/1 



High Solids 



Water 



TSS > 100 mg/1 



Low Solids 



Water 



TSS < 100 mg/ 1 



High Solids 



Water 



TSS > 100 mg/ 1 



Dissolved Oxygen 

 > 5.0 mg/1 



Coldwater 

 Gamef ish 



> 3.0 mg/1 



Warmwater 



gamef ish/ 



panf ish 



> 2.0 mg/1 



< 2.0 mg/1 



Rough f Ish 



Rough f ish 



a/ a/ 



Unfishable Unfishable 



Roughflsh 



a/ 



Unfishable 



Roughflsh 



a/ 



Unfishable 



Other unfishable conditions include pH greater than 10 or less than 5; temperature 

 greater than 32°C; summer flow zero. 



PROBLEMS IN APPLICATION TO MARINE RECREATIONAL FISHING 



Application of the above method to the case of marine recreational fishing 

 requires that we find some index or measure of water or ecosystem quality that 

 can be used to link changes in pollution discharges to changes in individuals' 

 participation decisions. Beyond this, we must have data on pre-policy levels 

 of quality and on the related level of participation. Further, it must be 

 possible to value in a defensible way pre-policy and post-policy participation. 

 Here we can continue to concentrate on the linkage requirement, since this 

 brings us to the core of the paper. 



First, let us note the several conditions that such a linking index or 

 measure must satisfy. 



44 



