Figure 13.3 Whitefish age structure. The whitefish population in Lake Erie experienced an unusually high amount of reproduction in 1944. However, young fish are not captured by fishing nets until they are 2 years old, so the large 1944 cohort was not detected until 1946. This large reproduction event led to age structures that were dominated by that cohort of fish in subsequent years.

Data from G. H. Lawler, Fluctuations in the success of year-classes of whitefish populations with special reference to Lake Erie, Journal of the Fisheries Research Board Canada 22 (1965): 1197–1227.