The critical feeding level is the feeding level at which the food intake is just high enough to cover the metabolic costs, with nothing left over for growth or reproduction.
Examples
# \donttest{
str(getFeedingLevel(NS_params))
#> num [1:12, 1:100] 0.622 0.622 0.605 0.621 0.616 ...
#> - attr(*, "dimnames")=List of 2
#> ..$ sp: chr [1:12] "Sprat" "Sandeel" "N.pout" "Herring" ...
#> ..$ w : chr [1:100] "0.001" "0.00119" "0.00142" "0.0017" ...
# }