marindicators (version 1.0.0)

fishingPressure: Calculates Fishing Pressure

Description

This function calculates Fishing Pressure on a fished group for \(j\) areas and \(i\) years.

Usage

fishingPressure(X, land, FP.groups, species.table, years)

Arguments

X

A dataframe of fishery independent data derived from research vessel survey data or model output, with columns YEAR, ID, SPECIES, and BIOMASS. YEAR indicates the year the observation was recorded, ID is an area code indicating where the observation was recorded, SPECIES is a numeric code indicating the species sampled, and BIOMASS is the corresponding biomass (stratified and corrected for catchability as required).

land

A dataframe of commercial landings data with columns YEAR, ID, SPECIES and CATCH. YEAR indicates the year the landing was recorded, ID is an area code indicating where the landing was recorded, SPECIES is a numeric code indicating the species landed, and CATCH is the corresponding landed weight (in the same units as BIOMASS in X).

FP.groups

A dataframe with two columns, which must be named group.land and group.X. Each row holds the group names to calculate the fishing pressure on a target group, with the numerator in column group.land and the denominator in column group.X. Each entry must be a character string matching the name of a column in species.table.

species.table

A table with column names that match the entries of FP.groups. The entries in each column are the species codes for the species included in that group. Species codes should be a subset of those in the SPECIES column of land (for groups in group.land) or X (for groups in group.X). species.table may also include columns for other species groups; these will be ignored. Note that an entry in FP.groups could be "ALL". In this case, a column in species.table named "ALL" is not required; the function will automatically include all species in land and/or X.

years

A vector of years for which to calculate indicator.

Value

Returns a dataframe with columns: ID and YEAR, and a column for each target group, named FP_group.X.

If biomass of group.X is NA and landings of group.land are zero, fishing pressure is set to zero. Otherwise, if biomass of group.X is NA, fishing pressure is set to NA.

Details

Fishing pressure (FP): $$FP = Landings_{FG}/Biomass_{FG}$$ where \(Landings_{FG}\) is the landed catch of the fished group and \(Biomass_{FG}\) is the biomass of the fished group.

This indicator measures the level of exploitation or total fishing pressure at the ecosystem or species group level. Change in this indicator can result from change in \(Landings_{FG}\), \(Biomass_{FG}\) or both. If \(Landings_{FG}\) and \(Biomass_{FG}\) change in the same direction, exploitation rate may not change.

References

Bundy A, Gomez C, Cook AM. 2017. Guidance framework for the selection and evaluation of ecological indicators. Can. Tech. Rep. Fish. Aquat. Sci. 3232: xii + 212 p.

Shin, YJ, Shannon LJ, Bundy A, Coll M, Aydin K, Bez N, Blanchard JL, Borges, MF, Diallo I, Diaz E, Heymans JJ, Hill L, Johannesen E, Jouffre D, Kifani S, Labrosse P, Link JS, Mackinson S, Masski H, M<U+00F6>llmann C, Neira S, Ojaveer H, Abdallahi KM, Perry I, Thiao D, Yemane D, and Cury PM. 2010. Using indicators for evaluating, comparing and communicating the ecological status of exploited marine ecosystems. Part 2: Setting the scene. ICES Journal of Marine Science, 67: 692-716

See Also

Other fishing pressure indicators: allPressure, landings, meanTLLandings, speciesRichness

Examples

# NOT RUN {
# Compile data
data(X)
data(land)
data(species.table)

# Species groups of interest
FP.groups <- data.frame(rbind(c("ALL", "ALL"), 
   c("CLUPEIDS", "CLUPEIDS.L"),
   c("FLATFISH", "FLATFISH.L"),
   c("GROUNDFISH", "GROUNDFISH.L")))
names(FP.groups) <- c("group.X", "group.land")

# Calculate indicators
fishingPressure(X = X, land = land, FP.groups = FP.groups, 
   species.table = species.table,  years = c(2014:2019))
# }