calc_ppr_index.Rd
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" )
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". |
Data frame:
Year of the index
Value of the index
Units: gC year^-1