Computes nominal effort estimate

The effort estimate is computed as the product of the fleet_engagement_number (derived from the active_vessels), the effort_fishable_duration (derivated from the active_days, and the effort_activity_coefficient computed with the compute_effort_activity_coefficient function.

The computation of the nominal effort estimate is done grouped by strata compound of year, month and fishing_unit. This strata can be extended with additional columns with the minor_strata argument.

Active vessels:

The active_vessels can be either time-dependent,ie given by year/month, year only or be atemporal, mainly depending on how and at which frequency the vessels census/survey is operated in the country.

An additional argument called active_vessels_strategy controls how to select the active_vessels data in time, when this data is time-dependent. The latest strategy will select the latest data acquired in time, while the closest will select the closest data acquired in time, which could be data acquired after the effort data considered.

As example, a vessel census is performed each five years, and data is available for 2007 and 2012. Effort data for 2011 needs to be computed. Which active_vessels data should be used? In case of a latest strategy, in 2011, the latest data available is 2007, so this one will be used. In the case of a closest strategy, in 2011, we used the closest vessel data (ie 2012), assuming it betters characterizes the fleet engagement for the year considered.

Active days:

In case of 'fisher_interview' (as source of the effort data), the active_days data should be ignored, as the days of the month will be used (and generated automatically by the function)

Usage

compute_effort_estimate(
  active_vessels,
  active_vessels_strategy = c("latest", "closest"),
  effort,
  effort_source = c("fisher_interview", "boat_counting"),
  active_days = NULL,
  landings,
  minor_strata = NULL,
  progress_fn = NULL
)

Arguments

active_vessels

active vessels

active_vessels_strategy

The strategy to associate the active vessels to the effort based on time. Active vessels period does not match necessarily the periods of data (effort, landings), and can be reported either by year or by year/month. This parameter let decide which methodology should be used to select the active vessels based on time. It can be either "latest" (taking the latest period), "closest" ie the closest active vessels in time, after or before the data period. In case 2 periods before/after are equally closer, the latest in time before the data period will be taken.

effort

effort data

effort_source

effort_source (register_interview / boat_counting)

active_days

active_days. Default is NULL (auto-generated)

landings

landings

minor_strata

minor_strata. Default is NULL

progress_fn

a progress function with args (i, n, label). Default is NULL