Ages and lengths of Bull Trout from two Rocky Mountain lakes at two times.

Assigned ages (from otoliths) and fork lengths of Bull Trout (Salvelinus confluentis) from two Rocky Mountain lakes in Alberta, CAN before and after a regulation change.

Format

A data frame with 96 observations on the following 4 variables:

age: Age (from otoliths).
fl: Fork length (mm).
lake: Lake (Harrison and Osprey).
era: Era of collection (1977-80 and 1997-01). See details.

Source

From (approximately) Figure 2 of Parker, B.R., D.W. Schindler, F.M. Wilhelm, and D.B. Donald. 2007. Bull trout population responses to reductions in angler effort and retention limits. North American Journal of Fisheries Management 27:848-859. CSV file

Note

The historical (1977-1980) era samples were from before restrictive sportfishing regulatory regimes were implemented (in the 1990s) that led to changes in abundance and population structure of bull trout.

Topic(s)

Growth
Von Bertalanffy growth model

Examples

data(BullTroutRML2)
str(BullTroutRML2)
#> 'data.frame':	96 obs. of  4 variables:
#>  $ age : int  14 12 10 10 9 9 9 8 8 7 ...
#>  $ fl  : int  459 449 471 446 400 440 462 480 449 437 ...
#>  $ lake: Factor w/ 2 levels "Harrison","Osprey": 1 1 1 1 1 1 1 1 1 1 ...
#>  $ era : Factor w/ 2 levels "1977-80","1997-01": 1 1 1 1 1 1 1 1 1 1 ...
head(BullTroutRML2)
#>   age  fl     lake     era
#> 1  14 459 Harrison 1977-80
#> 2  12 449 Harrison 1977-80
#> 3  10 471 Harrison 1977-80
#> 4  10 446 Harrison 1977-80
#> 5   9 400 Harrison 1977-80
#> 6   9 440 Harrison 1977-80
op <- par(mfrow=c(2,2),pch=19)
plot(fl~age,data=BullTroutRML2,subset=lake=="Harrison" & era=="1977-80",main="Harrison, 1977-80")
plot(fl~age,data=BullTroutRML2,subset=lake=="Harrison" & era=="1997-01",main="Harrison, 1997-2001")
plot(fl~age,data=BullTroutRML2,subset=lake=="Osprey" & era=="1977-80",main="Osprey, 1977-80")
plot(fl~age,data=BullTroutRML2,subset=lake=="Osprey" & era=="1997-01",main="Osprey, 1997-2001")

par(op)