Poster Presentation Society for Freshwater Science 2026 Annual Meeting

Investigating the predator-permanence hypothesis for macroinvertebrates in southeastern lentic habitats (134774)

Scott Messick 1 , Darold P Batzer 2
  1. Odum School of Ecology, University of Georgia, Athens, Georgia, USA
  2. Department of Entomology, University of Georgia, Athens, Georgia, USA

The predator-permanence hypothesis posits that two transitions – between temporary and permanent habitats and between habitats with and without fish predators – control the overall structure of animal assemblages in lentic freshwater systems. Evaluation of this concept, developed in the northern United States, at broader spatial scales has provided inconsistent results, however. To determine the applicability of this paradigm outside of the region in which it was conceived, we conducted a comparative analysis of macroinvertebrate communities across lentic habitats in Whitehall Forest, Athens, GA, USA, which vary principally in hydroperiod and fish assemblages. In order to characterize these communities, we collected benthic and littoral samples from 14 Whitehall pond and wetland habitats across a gradient of permanency (temporary, permanent) and predation regime (none, small fishes, small and large fishes) and will use non-metric multidimensional scaling (NMDS) to visualize community differences, as well as PERMANOVA for statistical differentiation. Adherence to or deviation from the predator-permanence hypothesis will be determined by comparing overall community structures across habitats and by examining the life history traits of major taxa within those structures. If our results follow those predicted by the hypothesis, we will observe more active, rapidly developing prey taxa and few predators in ephemeral habitats, large invertebrate prey and predators in permanent fishless habitats, and small, inactive invertebrate prey in permanent habitats containing fish. It is possible that some deviations will arise from the hypothesis, which may be due in part to the subtropical environment. As part of a larger collaborative project seeking to more wholistically characterize these aquatic communities, this macroinvertebrate-focused study aims to contribute to a better understanding of the applicability of a major paradigm for lentic community structure beyond the region in which it was conceived. Knowledge of how communities structure themselves in response to environmental and ecological stressors is crucial for informed biological control efforts (e.g. fish stocking/removal) and for predicting the effects of climate change on lentic habitats (e.g. shortening hydroperiod).

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  2. Batzer, D. P., L. B. Epele, and S. Reindl. 2024. Assessing the relative impacts of habitat size, hydrology, and fish occurrence on aquatic invertebrate assemblages in a set of depressional wetlands of Georgia, USA. Hydrobiologia 851:2519-2527.
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