Spatial modeling

[brianlangseth-NOAA]

Canary assessments going back many cycles have used a spatially implicit treatment with state-specific fleets. 2015 assessment modeled deviations on the allocation of recruitment to those areas. Jim and Chantel tested a coastwide assumption and there wasn't a large effect on model results. Based on that they question whether the work to make the model spatial is worth it.

[brianlangseth-NOAA]

The thesis by Brooks suggests there is a spatial differences in growth around mid-Oregon which, along with spatially specific recruitment allocation would make things more complex. Spatial differences in growth are common for rockfish, so will want to explore how to include.

Can do spearate growth morphs, or alternatively explore growth (platoons) parameterization at the top of the control file. Jason suggested this as an option for the 2015 assessment and is an option to explore. Unsure if it is the right way but adds more flexibility in the growth relationship.

Although variation in growth is likely, growth morphas have not been used in a west coast assessment before.

[brianlangseth-NOAA]

If able to report out area based relative biomass then may be more useful to keep spatial dynamics. Last assessment did not report area specific quantitities of interes.

Survey was not spatially stratified in last assessment but doing that on a state by state basis gives more support for spatial dynamics.

• [ ] To inform whether there is a spatial gradient with recruitment can look at WCGBTS and pre-recruit to see if year classes are moving through across all areas (CA, OR/WA) or if there is strong differences. Stronger differences in recruitment would provide more evidence for having spatial dynamics.

[brianlangseth-NOAA]

Rex sole in gulf of alaska used different growth growths. Brian has .zip folder of model files. Useful to look into as to how to have multiple growth patterns (email from ian on 9/7)