DWEFgec: Gear Efficiency Correction for Deepwater Electrofisher

In JVAdams/GLFC: Great Lakes Fishery Commission

Gear Efficiency Correction for Deepwater Electrofisher

Description

Use the relation between larval lamprey length and probability of catch in the deepwater electrofisher to derive a gear efficiency correction factor.

Usage

DWEFgec(llengthmm)

Arguments

llengthmm

A numeric vector of lengths (in mm) of live larval lampreys.

Details

Lake-stream IDs are combination of lake ID and stream ID e.g., 1.064 = lake ID + (stream ID)/1000.

For both estimate files (csvNew and csvOld), there should be no missing values in year, lake, or lscode. Both files may contain variables other than those required. Those with the same name as variables in streamInfo will be replaced. Others will be kept.

Value

A numeric vector equivalent to the inverse probability of capture, p, at length llengthmm., logit(p) = 1.732 - 0.0229*llengthmm. This correction factor can then be multiplied by the number of lamprey of that size captured to estimate the catch adjusted for gear efficiency.

References

Robinson, JM, MJ Wilberg, JV Adams, and ML Jones. 2014. Comparing methods for estimating larval sea lamprey (Petromyzon marinus) density in the St. Marys River for the purposes of control. Journal of Great Lakes Research 40(3):739-747. [link]

Examples

catch <- 1:6
lenmm <- seq(80, 180, 20)
adjcatch <- catch*DWEFgec(lenmm)
cbind(catch, lenmm, adjcatch)

JVAdams/GLFC documentation built on Jan. 5, 2023, 12:59 a.m.