Fish stocks

FLBEIA can support an unlimited number of stocks. They can be simulated using age structured dynamics as well as biomass dynamics. Age structured population growth is combined with an stock-recruitment relationship and there are several shapes available.



Within fleet component four processes are simulated; effort allocation (total effort and its allocation among metiers), catch production, price formation and capital dynamics (investment and disinvestment in vessels or technology). Fleet activity is divided in metiers, and within metiers stock catchability is considered homogeneous.



Covariates component is intended to incorporate all the variables that are not part of the biological or fleet components and that affect any of the operating model components or the management process. The number of covariates is, in principle, unlimited. The limitation could come from memory problems with R and/or the OS used.



At the moment the data are divided in two groups, biological data and catch data at stock level in the first group and abundance indices in the second. The data are generated by the observation model and it simulates the data collection of the whole OM



FLBEIA does not provide any stock assessment model but those built in FLR frame, e.g. FLXSA, can be used without any additional cost. Assessment models code in R, which input data can be simulated from the OM, could be use doing some adaptation in the input and output formats.



The advice is generated through the harvest control rule (HCR). At the moment there are several HCR available and all of them produce annual TAC advice.

"Very useful for managers!"

" Intuitive interpretation of the assessment!"

"Easy to use and export results."

" The team supporting this tool responds very quick to my queries!"

Discover FLBEIA Software by AZTI

Bio-Economic Impact Assessment using FLR

The model is seasonal, and the number of seasons as well as the season length, are selected by the user. Stochasticity is introduced into the model via montecarlo simulation. The model has no limitation in the number of the stocks, the number of fleets, the number of seasons or the number of iterations in the montecarlo simulation, the limitation is marked by the computer.
The configuration of the current toolbox presents several limitations that could be solved with additional coding; for example, trophic interactions among stocks, effort based harvest control rules… FLBEIA has been built in a modular and extensible way to simplify the incorporation of new models if necessary. At the moment basic coding has been completed and additional coding will be carried out at case study level according to the needs.


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