TroutDietSL: Size and diet data for lake and bull trout from Swan Lake,...

In droglenc/FSAmisc: Miscellaneous functions for simple fisheries stock assessment methods

Size and diet data for lake and bull trout from Swan Lake, Montana.

Description

Size (standard length, total length, and weight) and diet data (volume of three main prey categories) for Bull Trout (Salvelinus confluentus) and Lake Trout (Salvelinus namaycush) from Swan Lake, Montana, a lake where Lake Trout just recently had become established.

Format

A data frame with 470 observations on the following 2 variables.

number

A unique identification number for each fish.

species

A species code: BLT=bull trout, LKT=lake trout.

sl

Standard length (mm). Only recorded for bull trout.

tl

Total length (mm). Computed from equation in source for bull trout.

weight

Weight (g)

vol.ttl

Total volume (ml) of prey in the stomach.

vol.mysis

Volume (ml) of Mysis diluviana in the stomach.

vol.oi

Volume (ml) of other invertebrates in the stomach.

vol.fish

Volume (ml) of fish in the stomach.

num.dipter

Number of dipterans in the stomach.

num.pisidium

Number of Pisidium spp. in the stomach.

Topic(s)

• Length-Weigth

• Diet Overlap

Source

From the online supplement to Guy, C.S., T.E. McMahon, W.A. Fredenberg, C.J. Smith, D.W. Garfield, and B.S. Cox. 2011. Diet overlap of top-level predators in recent sympatry: Bull trout and nonnative lake trout. Journal of Fish and Wildlife Management 2:183-189.

Examples

data(TroutDietSL)
str(TroutDietSL)
head(TroutDietSL)

# The authors added a percent volume for each diet item for each fish
TroutDietSL$pvol.mysis <- TroutDietSL$vol.mysis/TroutDietSL$vol.ttl
TroutDietSL$pvol.oi <- TroutDietSL$vol.oi/TroutDietSL$vol.ttl
TroutDietSL$pvol.fish <- TroutDietSL$vol.fish/TroutDietSL$vol.ttl
# add empty variable
TroutDietSL$empty <- ifelse(TroutDietSL$vol.ttl==0,"YES","NO")
head(TroutDietSL)

droglenc/FSAmisc documentation built on Jan. 8, 2023, 12:59 a.m.