A function to calculate the total allowable catch (TAC). Based on the MSY (maximum sustainable yield) principle, the TAC is the product of either UMSY or FMSY and the available biomass, i.e. vulnerable biomass, in terminal year.

## Arguments

- Assessment
An Assessment object with estimates of UMSY or FMSY and terminal year vulnerable biomass.

- reps
The number of stochastic draws of UMSY or FMSY.

- MSY_frac
The fraction of FMSY or UMSY for calculating the TAC (e.g. MSY_frac = 0.75 fishes at 75% of FMSY).

## Value

A vector of length `reps`

of stochastic samples of TAC recommendation. Returns NA's
if missing either UMSY/FMSY or vulnerable biomass.