calc_ppr_index: Calculate the PPR index

In andybeet/indexPPR: Utilities to create ecosystem overfishing indices for the NEFSC State of the Ecosystem report

Calculate the PPR index

Description

Using ideas found in Pauly & Christensen's (1995) Nature publication, Primary Production Required is calculated as:

Usage

calc_ppr_index(
  catch,
  speciesTL,
  transferEfficiency = 0.1,
  speciesCode = "NESPP3"
)

Arguments

catch	Data frame. n x m Data containing the total catch (g) by each species in each year. Must include two columns named YEAR,catch, a third column must contain the NESPP3 codes
speciesTL	Data frame. m x anything. Species codes and trophic level for the most abundantly caught species. One column must be named NESPP3 and another Troph
transferEfficiency	Numeric scalar. The value of transfer efficiency to use in the PPR calculation. Range should be [0,1] (Default = 0.10)
speciesCode	Character string. The name of the column that holds the species codes. Default = "NESPP3".

Details

Units: gC year^-1

Value

Data frame:

YEAR	Year of the index
INDEX	Value of the index

andybeet/indexPPR documentation built on Jan. 23, 2025, 7:20 a.m.