# Find out if it is important to account for variation in "random effects"
# by comparing the residuals of a linear model without the random effects with 
# the potential random effects
lm.test<-lm(Z_TP~Z_Length, data=data)
lm.test.resid<-rstandard(lm.test)
# Species Effect
plot(lm.test.resid~ data$Fish_Species, xlab = "Species", ylab="Standardized residuals")
abline(0,0, lty=2)
# Lake Effect
plot(lm.test.resid~ data$Lake, xlab = "Lake", ylab="Standardized residuals")
abline(0,0, lty=2)