The effect of algal flux in surface vs. pore water on the feeding of juvenile unionids

Session: 48. - Physical Ecology in Large Lakes and their Watersheds

Victor Fung, University of Guelph, [email protected]
Josef Ackerman, University of Guelph, [email protected]

Abstract

Unionid mussels are important constituents of Great Lakes’ benthos, yet little is known about their early life history, especially their feeding on surface and pore waters under flowing conditions in tributaries. We examined the clearance rates (CR) of recently metamorphosed juvenile Lampsilis siliquoidea (3–4 weeks old) in a racetrack flow chamber system under ecologically relevant  flow conditions.  Juveniles were exposed to river water or pore water from their native river and CR were determined from changes in algal concentration measured with a calibrated fluorometer and imaging flow cytometry (FlowCAM) to enumerate specific algal taxa CR.  Surprisingly algal concentrations were higher in pore vs. surface waters conditions, and varied temporally and spatially in the riverbed.  Mussel CR were generally higher for porewater and increased with algal flux regardless of the source. Some differences in the CR of specific algal taxa were evident and are under investigation. Results from this study will inform mussel biology, stream biogeochemistry and conservation efforts directed at population augmentation/reintroduction via artificial propagation.

1. Keyword
mussels

2. Keyword
phytoplankton

4. Additional Keyword
porewaters

5. Additional Keyword
flux

6. Additional Keyword
clearance rate