Walleye length at age
These data give length and age for over 3000 walleye (a type of fish) captured in Butternut Lake, Wisconsin, in three periods with different management method in place.
A data frame with 3198 observations on the following 3 variables.
Age of the fish, years
1 = pre 1990, 2 = 1991-1996, 3=1997-2000
Weisberg, S. (2014). Applied Linear Regression, 4th edition. Hoboken NJ: Wiley.