Kaitlin Schiller
Pronouns: she/they
Research Mentor(s): Karen Alofs
Research Mentor School/College/Department: School for Environment and Sustainability / SNRE
Program:
Authors: Peter Flood, Kaitlin Schiller
Session: Session 6 3:40-4:30 p.m. Hussey Room
Poster:
Abstract
Species around the globe are shrinking as a result of climate change, including freshwater fishes. Changes in fish size and growth patterns have implications for predation risk, nutrient transport, and provisioning, and understanding changes in size is vital to preserving ecosystems and fisheries. While theories exist to predict changes in ectotherm body size and growth patterns as a response to temperatures, previous studies have provided mixed results. In this study, we investigated the changes in mean age-at-length for Lepomis gibbosus (Pumpkinseed Sunfish), a mid-trophic level fish prevalent in Michigan. Sampling information from Michigan lakes over the last seven decades was used to model mean age-at-length as a response to nine different ecological variables. Boosted regression trees (BRTs) were able to predict over 33% of the variation in pumpkinseed age-at-length for all age classes, with latitude and sampling year being statistically important for 7 of the 9 age classes. The BRTs found that across age groups, higher latitudes corresponded with smaller fish populations, but that while younger fish decreased in size with increasing years and temperatures, older fish increased in size. Although these findings largely match our hypotheses, the variation among age groups indicates these measurements taken on a singular collection date may not reflect the environmental changes that occur over a fish’s entire lifespan.
