From Surface to Shell: A Limnological Investigation of Clam Populations in the Coeur d'Alene River Basin
Faculty Mentor
Joanna Joyner-Matos
Presentation Type
Poster
Start Date
May 2025
End Date
May 2025
Location
PUB NCR
Primary Discipline of Presentation
Biology
Abstract
Over a century of mining in Idaho deposited trace metal pollution into the Coeur d’Alene River and its lateral lakes. Because these lakes are used recreationally, investigating the impacts of metal contaminants on water quality and macroinvertebrate communities is crucial. In 2020, our lab analyzed fingernail clams (Sphaeriidae) and limnology of the lateral lakes. In 2024, our lab repeated this study at four lakes: three metal-containing (Rose L., Bull Run L., and Medicine L.) and one non metal-polluted lake (Benewah L.). We collected data monthly from June to September. We measured several limnological (water) features: temperature, pH, dissolved O2, conductivity, hardness, and alkalinity. Clams were collected using dip nets, measured, and dissected to determine reproductive output. Benewah L. and Medicine L. had significantly higher water temperatures (p<0.05) than Rose L. and Bull Run L. Additionally, Bull Run L. had significantly lower dissolved O2 than Benewah L. and Rose L. (p<0.001). All lakes differed significantly in hardness (p<0.05), with hardness lowest in Bull Run L. Clams from Bull Run L. were significantly larger than clams from Rose L. and Medicine L. (p<0.05) and they had significantly higher reproductive output (brood count/shell length) than did clams from Medicine L. (p<0.05). Low clam sample size from the non-polluted lake (Benewah L.) limits our ability to interpret the effects of metal exposure. These results suggest that, within a metal-rich environment, water temperature and/or dissolved O2 may strongly influence clam fitness. Future research should explore these environmental features across the full clam reproductive cycle.
Recommended Citation
McGuire, Natalie P.; Merritt, Sayla M.; Sanok, Joanna L.; and Hamada, Emily J.A., "From Surface to Shell: A Limnological Investigation of Clam Populations in the Coeur d'Alene River Basin" (2025). 2025 Symposium. 15.
https://dc.ewu.edu/srcw_2025/ps_2025/p2_2025/15
Creative Commons License
This work is licensed under a Creative Commons Attribution-NonCommercial-No Derivative Works 4.0 International License.
From Surface to Shell: A Limnological Investigation of Clam Populations in the Coeur d'Alene River Basin
PUB NCR
Over a century of mining in Idaho deposited trace metal pollution into the Coeur d’Alene River and its lateral lakes. Because these lakes are used recreationally, investigating the impacts of metal contaminants on water quality and macroinvertebrate communities is crucial. In 2020, our lab analyzed fingernail clams (Sphaeriidae) and limnology of the lateral lakes. In 2024, our lab repeated this study at four lakes: three metal-containing (Rose L., Bull Run L., and Medicine L.) and one non metal-polluted lake (Benewah L.). We collected data monthly from June to September. We measured several limnological (water) features: temperature, pH, dissolved O2, conductivity, hardness, and alkalinity. Clams were collected using dip nets, measured, and dissected to determine reproductive output. Benewah L. and Medicine L. had significantly higher water temperatures (p<0.05) than Rose L. and Bull Run L. Additionally, Bull Run L. had significantly lower dissolved O2 than Benewah L. and Rose L. (p<0.001). All lakes differed significantly in hardness (p<0.05), with hardness lowest in Bull Run L. Clams from Bull Run L. were significantly larger than clams from Rose L. and Medicine L. (p<0.05) and they had significantly higher reproductive output (brood count/shell length) than did clams from Medicine L. (p<0.05). Low clam sample size from the non-polluted lake (Benewah L.) limits our ability to interpret the effects of metal exposure. These results suggest that, within a metal-rich environment, water temperature and/or dissolved O2 may strongly influence clam fitness. Future research should explore these environmental features across the full clam reproductive cycle.
