adjustconsumption: Adjust for overconsumption

Description Usage Arguments Value

View source: R/function.R

Description

For each prey an upper limit needs to be set on the total amount consumed by all predators so as not to obtain more consumption than available biomass. Consumption is limited to 95% (R_M) of the available biomass. This is implemented by scaling target consumption by all predators. Let R_prey(l) be the Ratio consumed and R_M be the maximum ratio consumed then

R_{prey}(l)=\frac{∑_{pred}∑_{L}C_{pred,prey}(L,l)}{N_{prey}(l)W_{prey}(l)}

If R_prey(l)>R_M consumption is adjusted as follows

C_{pred,prey}(L,l)=R_MN_{prey}(l)W_{prey}(l)\frac{C_{pred,prey}(L,l)}{∑_{pred}C_{pred,prey}(L,l)}

Usage

1
adjustconsumption(catches, predation, stocks, i, maxratioconsumed)

Arguments

C

is the commercial catch of prey

S

is the survey catch of prey

E

is the consumption of prey by predator

N

is the total number of prey

opt

gadget options list

Value

a list with adjusted catches/consumption for C, S and E.


bthe/rgadget documentation built on Oct. 21, 2018, 5:16 p.m.