Comparing bluegill growth among newly constructed, renovated, and established flood-control reservoirs in southeastern Nebraska

Abstract

Perrion MA, Lebsock JR, Werner JP, Blank AJ, Miller BT. 2024. Comparing bluegill growth among newly constructed, renovated, and established flood-control reservoirs in southeastern Nebraska. Lake Reserv Manage. 40:57–65. Multiple reservoirs have been constructed in the last 10 yr in southeastern Nebraska for flood control and recreational purposes. In addition, other existing reservoirs have undergone major renovations in the same time period to remove sediment and aquatic invasive species. This situation created the opportunity to compare bluegill (Lepomis machrochirus) growth between newly constructed, renovated, and established reservoirs. This study analyzed bluegill growth data from 8 different flood-control reservoirs in southeastern Nebraska in 2021 and 2022. The study objectives were to (1) determine aging precision of scales and otoliths in bluegill and (2) evaluate bluegill growth among new, renovated, and established flood-control reservoirs. For all bluegill collected during the study, exact percent agreement for otolith ages between 2 readers was 89.6%, and percent agreement was 99.1% within 1 yr of age. For scales, exact percent agreement was 48.0% and 84.3% within 1 yr. Mean lengths at age for all reservoir types were similar for age-2 bluegill, whereas age-3 bluegill had longer mean lengths in renovated reservoirs than in either new or established reservoirs. Mean lengths of age-4 bluegill from new and renovated reservoirs were similar, but greater than mean lengths of age-4 bluegill in established reservoirs. Results of this study further demonstrate the greater precision of whole view otolith aging for bluegills compared to scale estimates and will benefit future managers making management decisions for bluegills. Managers can also use information ascertained from bluegill growth metrics to further manage bluegill populations based on reservoir age and management objectives.