

Comprehensive 

 Catch/Consumption Analysis 



• Estimate arithmetic average consumption rate by species and 

 by total catch for the total exposed population and for sub- 

 populations. For seasonal fisheries, consumption rates may be 

 estimated on an annual and a seasonal basis. 



Only selected steps may be performed in a given exposure assessment, 

 depending on data availability, study objectives, and funding Umita- 

 tions. Note that many of the steps to characterize harvest activities and 

 consumption rates apply only to analyses of recreational fisheries. 

 When estimating consumption of fish and shellfish of commercial 

 origin, harvest activities are irrelevant. Also, the specific geographic 

 origin of commercial fisheries products is often unknown. 



Two approaches to estimating consumption rates are outlined below. 

 In the first approach, a comprehensive analysis of a recreational fishery 

 is performed based on extensive catch/consumption data for the ex- 

 posed population. In the second approach, estimates of consumption 

 rates are based on available values for the U.S. population (or sub- 

 populations) or other assumed values. Most of the available estimates 

 were derived from recall or diary studies (Lindsay 1986) and include 

 commercial fisheries products. It is recommended here that local or 

 regional assessments of fishery consumption be performed whenever 

 possible to avoid possible errors inherent in extrapolating standard 

 values for the U.S. population to distinct subpopulations. Moreover, 

 extrapolation of standard consumption estimates that include com- 

 mercial fisheries products to recreational fisheries should generally be 

 avoided. 



In developing a profile of the exposed population, there is no single 

 "correct" estimate of consumption rate. Because consumption rates are 

 highly variable, use of a range of values or a probability distribution for 

 consumption rate estimates is recommended. This approach may also 

 be followed when estimating consumption rates for subpopulations of 

 interest. 



An alternative to the typical practice of basing risk estimates on 

 selected consumption rates involves presenting risk estimates graphi- 

 cally for a wide range of consumption rates that essentially includes all 

 possible realistic values (see below. Presentation and Interpretation 

 of Results). For example, plots of estimated risk vs. consumption rate 

 may be useful for public presentations on recreational fishery resour- 

 ces. In this case, the risk associated with any particular subgroup within 

 the exposed population may be evaluated by selecting a consumption 

 value for the subgroup and reading the corresponding risk from the 

 graphic plot. Use of this approach avoids having to collect extensive 

 data on the exposed population. A similar approach involves selecting 

 an "acceptable" (tolerable) risk level and providing advice on levels of 

 consumption, such that the "acceptable" risk is not exceeded. The 

 advantage of both of these approaches is that consumption rates need 

 not be determined or assumed. 



Appropriate field survey forms, data analyses, and format for presen- 

 tation of results for a comprehensive catch/consumption analysis of 



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