calc_mtl_index.Rdmean Trophic Level is calculated from a time series of landings: It is the sum of the species Trophic levels #' weighted by their landings #'
calc_mtl_index(catch, speciesTL, speciesCode = "NESPP3")
| speciesTL | dataframe. m x anything. Species codes and trophic level for the most abundantly caught species. One column must be named NESPP3 and another Troph |
|---|---|
| speciesCode | Character string. The name of the column that holds the speciesCodes. Default = "NESPP3". |
| data | dataframe. n x anything. Data containing the total catch by each species in each year. A complete grid of year by species must be passed. Columns must be named YEAR,NESPP3,catch. |
Data frame:
Year of the index
Value of the index