In iantaylor-NOAA/Lingcod_2021: Estimate the Status of Lingcod off the US West Coast in 2021

Investigating and or addressing the following items could improve future assessments of r spp:

• Sex-specific selectivity is likely given the life history of r spp. However, knowledge of the fine-scale spatial distribution of ages and sexes relative to the distribution of fishing effort and survey sampling locations is lacking to inform these patterns. Some relationships may be dome-shaped while others may be asymptotic and these relationships could depend on whether the process is governed by length or age. Care should be taken during explorations of selectivity to ensure that the model does not become overparameterized given that selectivity and mortality are correlated.
• Some data sources that were provided by state representatives were not fully explored, e.g., information from video landers and \glspl{rov}. Currently, there is not a method to include multiple indices for a given fishery, and thus, the best-case scenario would be to provide comparisons of model results given fits to these alternative data sources rather than those that were used to fit the model. Additional work would be needed to formulate a method to combine them or allow for the inclusion of multiple \gls{cpue} indices for a given fleet.
• It is likely that natural mortality is not constant across age as it was parameterized. Exploration of the Lorenzen natural mortality function produced results that were similar to the base model for the north and implausibly low in the south. Additional approaches are available to model age-specific natural mortality that could also be explored.
• Data-weighting approaches that separate tuning of sample sizes for discarded and retained fish from the same fleet should be explored such that data on discard rates and mean body weight can be weighted appropriately. These changes will hopefully bring the estimates of total mortality for years with high discard rates closer to the values reported in the \gls{gemm} data product based on data collected by \gls{wcgop}.
• Conflicts were present in the information provided by the age and length data.

iantaylor-NOAA/Lingcod_2021 documentation built on Oct. 30, 2024, 6:42 p.m.