Water temperature influences the suitability of a lake for walleye and largemouth bass

Can you draw the relationship between these two fish and lake temperature?

Lake temperature in this study is measured as growing degree days (GDD).

GDD are a measure of cumulative temperature over the entire open water season of a lake (from ice-out to ice-on). Higher GDD means warmer water, lower GDD means cooler water. In this case, we used a base temperature of 5 degrees C (41 degrees F). We calculated GDD for each lake and each year: for each day that the water temperature was above 5 degrees C, subtract 5 from the water temperature (in C) for that day. GDD is the sum of all of those numbers for the entire year.

What are growing degree days?

We're giving you a hint to help you fill out the pattern for Walleye and Largemouth Bass. Walleye are most likely to reproduce in cooler lakes. Largemouth Bass are more likely to reach high abundance in warmer lakes, so their line looks like this: . It's up to you to figure out what happens to walleye in warmer lakes.

Probability of walleye is higher than largemouth bass in cooler lakes and lower in warmer lakes.