Forward projection module

The forward projection module (fwd) is an object of class mseCtrl that contains the arguments governing stock and fleet effort dynamics given management advice. This module is NOT, strictly speaking, a part of the management procedure but provides important options for evaluating different fleet activity assumptions, levels of implementation error and projection stochasticity.

Inputs

MixME makes use of the args slot of the mseCtrl object. There are six input arguments to the fwd module - some are optional and others are specified by default when assembling inputs using makeMixME. These defaults should work for most simulations but it is worth discussing each argument to explore the range of possible simulations that can be carried out with MixME.

adviceType

This argument is a character that specifies whether management advice based on catch or landings. Possible inputs are 'catch' or 'landings'. The default value for adviceType is 'catch'.

effortType

This argument is a character that specifies whether fleet effort is constrained by the most-limiting ('min') or the least-limiting ('max') stock. Possible inputs are 'min' or 'max'. The default value for effortType is 'min'.

exceptions

This argument is a numeric matrix with stocks on rows and fleets on columns. Matrix elements are '1' or '0'.

This argument allows for the exclusion of selected stocks from fleet effort optimisation. Stocks can be excluded from limiting the effort of a specific fleet or all fleets. This is a powerful argument that allows you to build simulations where specific fleets target a single stock or are constrained by a select group of target species. At least one stock must be limiting for each fleet.

By default, all matrix elements are '1' - so all stocks are effort-limiting for all fleets that exploit them.

multiplier

This argument is a numeric matrix with stocks on rows and fleets on columns. Matrix elements are positive real numbers.

The argument allows for implementation error in application of catch advice in each year. Specifically, it allows fleets to systematically deviate from quota restrictions by a specified fraction whilst using the original quota target to evaluate management performance. This is useful if we want to test the robustness of management to, say, a 10 % annual over-quota catch by one or more fleets. In this case, advice is not being altered to increase available quota, and performance statistics will report these additional catches as overfishing, but fleet effort dynamics will use the inflated over-quota catch target.

By default, all matrix elements are '1' - so there is no implementation error for any stock or fleet.

sr_residuals

This argument is optional and takes the form of a named list of stocks. Each element is an FLQuant containing the pre-sampled multiplicative recruitment residuals for each year and iteration.

proc_res

This argument is not currently operational.

Methods