Figure 2: Lake Erie yellow perch cohort size at age-2 and lifetime harvest by cohort plotted against juvenile abundance, 1987–2010. | Nature Communications

Figure 2: Lake Erie yellow perch cohort size at age-2 and lifetime harvest by cohort plotted against juvenile abundance, 1987–2010.

From: Short winters threaten temperate fish populations

Figure 2

Juvenile(age-0) abundance (1987–2010) was determined from annual, fishery-independent Ohio Department of Natural Resources-Division of Wildlife bottom trawling surveys conducted during October in (a) western and (b) central Lake Erie, and is presented as CPUE (# of individuals per trawl minute) in year t (year in which each cohort was hatched). Estimates of cohort size at age-2 in year t+2 for (a) western and (b) central Lake Erie (1987–2010) were generated by the Great Lakes Fishery Commission’s Lake Erie Yellow Perch Task Group48. Lifetime harvest by cohort in (c) western and (d) central Lake Erie is the cumulative harvest by commercial fishers and recreational anglers (1987–2008) at ages 2–5 (that is, years t +2 through t+5)48. Linear regression was used to relate cohort size at age-2 and lifetime harvest by cohort to fall juvenile abundance. Results indicate fall juvenile abundance is a good proxy for future recruitment to age-2, when yellow perch typically become reproductively mature and enter the fishery. Thus, recruitment to the fishery is strongly influenced by factors operating prior to first fall of life, with strong recruitment events supporting Lake Erie’s commercial and recreational fisheries for many years afterwards.

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