Oral Presentation Freshwater Sciences 2023

Assessing freshwater mussel (Unionida) assemblage patterns by life history guilds, taxonomic groupings, and conservation status among unglaciated, partially glaciated, and fully glaciated river drainages in eastern North America (#185)

Aaliyah D Wright 1 , David T Zanatta 2
  1. Society for Freshwater Science, Mount Pleasant, MICHIGAN, United States
  2. Biology, Central Michigan University, MOUNT PLEASANT, USA, MI, United States

Freshwater systems across North America rely on unionid mussels as important nutrient cyclers, natural water filterers, and water quality indicators. Unionids have an important outsized influence on benthos community structure, but remain understudied. This study expands upon previously published work by Moore et al. (2021). The Moore et al. (2021) study aimed to use ordination techniques to evaluate if the three freshwater mussel life history strategies (Periodic, Equilibrium, and Opportunistic) proposed by Haag (2012) can be distinguished quantitatively. Moore et al. (2012) concluded that ordinations could reliably group many species into their presumed life history groups; however, there was still more research that needed to be conducted. Our study explores geographic patterns with respect to the complex life histories of unionid mussels in the Laurentian Great Lakes drainage (fully glaciated), The Ohio River drainage (partially glaciated), and the Tennessee and Cumberland river basins (unglaciated). Each of these major river drainages differ in their species assemblages of freshwater mussels and their respective life history strategies. We also evaluated if there are relationships among glaciated, partially glaciated, and unglaciated areas and if there are patterns related to unionid distributions and conservation status. Preliminary analyses showed relationships between species’ conservation status (G-rank) and river drainage (P < 0.001) and potentially between life history groups and the three river drainages (P = 0.12).  From this it can be inferred that a watershed’s glacial history has considerable impact on species distribution and colonization of recently deglaciated regions may be in part dependent on the life history of a unionid species.