User menu
We are developing Statistical-Catch-At-Size (SCAS) base on ADMB to extend the previous ASPM (later SCAA), which have been used since 2001 inclduing other IOTC species such as yellowfin tuna, albacre tuna and swordfish.
ASPM/SCAA has two major limitations, i.e., (a) selectivities are estimated by model free (ad hoc) approches and (b) CAA is estimated by the slicing methods. These two produce biases in different leveles. To solve thses problems we developed SCAS by modifying ASPM/SCAA softwear including the model based slectivity estimation scheme and to use CAS to avoid biases caused by slicing meghod to estimnate CAA. Although we made such modidifications, the basic designs of SCAS is remained same as ASPM/SCAA software.
The SCAS is now similar to SS3 except two points, i.e., (a) annual basis (season aggretaed) (SS3 normaly quarter basis) and (b) no spatial structrure avaialble as in SS3. We have not yet comleted the future projections and risk assessments parts, thus for this time we did only stock assessments without Kobe II. In the futrue we will complete all parts. The reason why we use SCAS is that SC has been recommending to use diffetent types (strutured) of stock assessment models (e.g. integtaed models such as SS3, prodcution model such as ASPIC and many other types) to compare and confrim results.
We are using BET in the Indian Ocean under a single stock assumption.
