kalebentley
commented
4 months ago The following code has been added to the .Rmd:
summary - creel surveys dates by section where estimated total effort for a particular "angler_final" grouping was >0 group but no interviews were obtained
inputs_pe$daily_cpue_catch_est |> filter(is.na(est_cg), angler_hours_daily_mean>0)
In the function "prep_inputs_pe_daily_cpue_catch_est", the "catch_estimate" for a particular "angler_final" and "section_sum" group is estimated to zero if no interviews are obtained on a given survey date.
I don't have a good handle on how big (or really how little) of an issue this might be within and among fisheries. I'm guessing it is fairly rare to have zero interviews for a given angler type, section, and date and when it does happen it most likely is a result of little to no estimated angler effort (i.e., very few anglers fishing on a given day/section). However, this may not always be the case and, in fact, could also be an artifact of sampling effort and/or logistics. For instance, in some fisheries, boat angler interview/contacts can be somewhat challenging to obtain. There could instances where there's non-negligible angler effort and thus the potential for catch >0 but again zero interviews were conducted. Here, estimates of catch on that day (and thus overall) are likely going to be systematically underestimated.
In the old creel analysis script, I imputed some sort of average CPUE to use when zero interviews were conducted on a survey date. There are many different ways this type of approach could be implemented (each with an implicit set of assumptions). Alternatively, the data for the given date/section/angler_final grouping could be dropped when no interviews were conducted prior to estimating catch (with the function "est_pe_catch") so that catch is estimated for this day AND not assumed to be zero (simply because no interviews were obtained).
As a near-term solution, a summary table could be generated highlighting the number of dates by angler type and section when zero interviews were conducted to highlight when catch was estimated to be zero as a result of this data analysis quirk.