Calculate the PPR index

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

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".

Value

Data frame:

YEAR

Year of the index

INDEX

Value of the index

Details

Units: gC year^-1