Mirex concentration, weight, capture year, and species of Lake Ontario salmon.

Mirex concentration, weight, capture year, and species of Lake Ontario Coho and Chinook salmon.

Format

A data frame with 122 observations on the following 4 variables.

year: a numeric vector of capture years
weight: a numeric vector of salmon weights (kg)
mirex: a numeric vector of mirex concentration in the salmon tissue (mg/kg)
species: a factor with levels chinook and coho

Source

From (actual data) Makarewicz, J.C., E.Damaske, T.W. Lewis, and M. Merner. 2003. Trend analysis reveals a recent reduction in mirex concentrations in Coho (Oncorhynchus kisutch) and Chinook (O. tshawytscha) Salmon from Lake Ontario. Environmental Science and Technology, 37:1521-1527. CSV file

Details

The year variable should be converted to a factor as shown in the example.

Topic(s)

Linear models
Other

Examples

Mirex$year <- factor(Mirex$year)
lm1 <- lm(mirex~weight*year*species,data=Mirex)
anova(lm1)
#> Analysis of Variance Table
#> 
#> Response: mirex
#>                     Df  Sum Sq  Mean Sq F value    Pr(>F)    
#> weight               1 0.22298 0.222980 60.0785 8.586e-12 ***
#> year                 5 0.50667 0.101333 27.3028 < 2.2e-16 ***
#> species              1 0.00000 0.000001  0.0004 0.9840448    
#> weight:year          5 0.09491 0.018982  5.1143 0.0003287 ***
#> weight:species       1 0.00240 0.002397  0.6457 0.4235926    
#> year:species         5 0.02338 0.004677  1.2601 0.2873654    
#> weight:year:species  5 0.01650 0.003299  0.8890 0.4916170    
#> Residuals           98 0.36372 0.003711                      
#> ---
#> Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1