Drs. Shelley Arnott, Alison Derry (UQAM), and Kathryn Cottingham (Dartmouth) are championing a global experiment to investigate genetic variation in salt tolerance responses within the freshwater zooplankton species Daphnia pulicaria/pulex, an herbivore crustacean. This project is currently accepting participants from around the world. If you are interested in participating, please visit our Lab Opportunities page. Continue reading to learn more about the Global Daphnia Salt Tolerance Project.
Background
Salinity (measured as chloride concentration or electrical conductance) in lakes and streams is increasing because of human activities. Agriculture, mining (e.g., potash), climate change events, such as drought and sea water intrusion in coastal regions, and the winter application of salt-based de-icers to icy paved roads, parking lots, and sidewalks all contribute to the increasing salinity of freshwater bodies (Hebert et al. 2015, Dugan et al. 2017, Kaushal et al. 2018, Thorslund et al. 2021, Sorichetti et al. 2022).
Salinization, the increasing salinity of freshwater bodies such as lakes and streams, has led to severe impacts on aquatic communities and food webs (Hintz and Relyea 2017, Castillo et al. 2018, Astorg et al. 2021). Yet there is still a lot we don’t know about how increasing salt in lakes, ponds, and streams is affecting biodiversity worldwide because responses to salinization vary substantially between regions (e.g., Jeppesen et al. 2007, Moffett et al. 2021, Greco et al. 2022). This variation in responses also limits the efficacy of national water quality guidelines. For example, some locations experience dramatic declines in freshwater community abundance at chloride concentrations well-below current water quality guidelines (Hintz, Arnott et al. 2022).
Some of the variation among responses to salt pollution may be caused by local environmental conditions, including water hardness (Elphick et al. 2011, Soucek et al. 2011), food quality (Isanta-Navarro et al. 2021) and food quantity (Brown and Yan 2015). There is also some evidence of within-species variation in salt tolerance within regions or habitats (Weider and Hebert 1987, Venancio et al. 2018, Loureiro et al. 2012). Indeed, recent studies have suggested that Daphnia can evolve a higher tolerance to increased salinity (Coldsnow et al. 2017, Hintz et al. 2018). This variation can constrain our ability to protect aquatic organisms, because water quality guidelines based on toxicity tests of animal cultures maintained in laboratories may not reflect the range of sensitivities found in nature.
It is critical that we evaluate the variation in salt tolerance within species across a wide geographic area and the factors that are associated with this variation.
Background
Salinity (measured as chloride concentration or electrical conductance) in lakes and streams is increasing because of human activities. Agriculture, mining (e.g., potash), climate change events, such as drought and sea water intrusion in coastal regions, and the winter application of salt-based de-icers to icy paved roads, parking lots, and sidewalks all contribute to the increasing salinity of freshwater bodies (Hebert et al. 2015, Dugan et al. 2017, Kaushal et al. 2018, Thorslund et al. 2021, Sorichetti et al. 2022).
Salinization, the increasing salinity of freshwater bodies such as lakes and streams, has led to severe impacts on aquatic communities and food webs (Hintz and Relyea 2017, Castillo et al. 2018, Astorg et al. 2021). Yet there is still a lot we don’t know about how increasing salt in lakes, ponds, and streams is affecting biodiversity worldwide because responses to salinization vary substantially between regions (e.g., Jeppesen et al. 2007, Moffett et al. 2021, Greco et al. 2022). This variation in responses also limits the efficacy of national water quality guidelines. For example, some locations experience dramatic declines in freshwater community abundance at chloride concentrations well-below current water quality guidelines (Hintz, Arnott et al. 2022).
Some of the variation among responses to salt pollution may be caused by local environmental conditions, including water hardness (Elphick et al. 2011, Soucek et al. 2011), food quality (Isanta-Navarro et al. 2021) and food quantity (Brown and Yan 2015). There is also some evidence of within-species variation in salt tolerance within regions or habitats (Weider and Hebert 1987, Venancio et al. 2018, Loureiro et al. 2012). Indeed, recent studies have suggested that Daphnia can evolve a higher tolerance to increased salinity (Coldsnow et al. 2017, Hintz et al. 2018). This variation can constrain our ability to protect aquatic organisms, because water quality guidelines based on toxicity tests of animal cultures maintained in laboratories may not reflect the range of sensitivities found in nature.
It is critical that we evaluate the variation in salt tolerance within species across a wide geographic area and the factors that are associated with this variation.
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The goals of the Global Daphnia Salt Tolerance Project
1. To compare tolerance to chloride (NaCl) among Daphnia pulicaria/pulex populations (iso-female lines). 2. To relate environmental conditions of site of origin to NaCl tolerance. Scope Researchers from around the world are participating in the project. Researchers will be collecting Daphnia from lakes in Canada, USA, Europe, and Japan (anywhere D. pulicaria is found), across a range of environmental conditions including concentrations of chloride and other stressors such as metal concentrations. Methods We will use a common garden approach to test sensitivity to NaCl, a commonly used road salt. All Daphnia will be grown in standardized conditions. The ten individuals will be exposed to each of 10 concentrations of NaCl-amended COMBO at concentrations ranging from 18 to 2700 mgCl/L. After 48 hours, the number of surviving individuals will be counted and LC50 (i.e., the concentration where 50% mortality occurs) will be calculated. This will be repeated for each water body, with ten identical individuals being tested at each concentration, for each lake. LC50 among sites will be compared and related to environmental conditions (chloride and other ion concentrations, nutrient levels, and dissolved oxygen). |
Photo of Daphnia by Carrie Ewins.
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References
Dugan, H. A., S. L. Bartlett, S. M. Burke, J. P. Doubek, F. E. Krivak-Tetley, N.K. Skaff, J. C. Summers, K. J. Farrell, I. M. McCullough, A. M. Morales-Williams, D. C. Roberts, Z.Ouyang, F. Scordo, P. C. Hanson, and K.C. Weathers. 2017. Salting our freshwater lakes. Proc. Natl. Acad. Sci. U. S. A. 114.17: 4453-4458.
Elphick J. F., K. D. Bergh, and H. C. Bailey. 2011. Chronic toxicity of chloride to freshwater species: effects of harness and implications for water quality guidelines. Environ. Toxicol. Chem. 30:239-246.
Greco, D. S.E. Arnott, I. Fornier, B. Schamp. 2021. Effects of chloride and nutrients on freshwater zooplankton communities. Limnology and Oceanography Letters.
Herbert, E. R., P. Boon, A. J. Burgin, S. C. Neubauer, R. B. Franklin, M. Ardon, K. N. Hopfensperger, L. P. M. Lamers, and P. Gell. 2015. A global perspective on wetland salinization: ecological consequences of a growing threat to freshwater wetlands. Ecosphere 6:206
Hintz, W. D., B. M. Mattes, M. S. Schuler, D. K. Jones, A. B. Stoler, L. Lind, and R. A. Relyea. 2017. Salinization triggers a trophic cascade in experimental freshwater communities with varying food-chain length. Ecol. Appl. 27: 833–844, doi:10.1002/eap.1487
Hintz, W. D. and R. A. Relyea. 2019. A review of the species, community, and ecosystem impacts of road salt salinisation in fresh waters. Freshwater Biol. 64: 1081–1097, doi:10.1111/fwb.13286
Hintz, W. D., S. E. Arnott, C. C. Symons, D. A. Greco, A. McClymont, J. A. Brentrup, M. Cañedo-Argüelles, A. M. Derry, A. L. Downing, D. K. Gray, S. J. Melles, R. A. Relyea, J. Rusak, C. L. Searle, L. Astorg, H. K. Baker, B. E. Beisner, K. L. Cottingham, Z. Ersoy, C. Espinosa, J. Franceschini, A. T. Giorgio, N. Göbeler, E. Hassal, M.-P. Hébert, M. Huynh, S. Hylander, K. L. Jonasen, A. E. Kirkwood, S. Langenheder, O. Langvall, H. Laudon, L. Lind, M. Lundgren, L. Proia, M. S. Schuler, J. B. Shurin, C. F. Steiner, M. Striebel, S. Thibodeau, P. Urrutia-Cordero, L. Vendrell-Puigmitja, G. A. Weyhenmeyer. Current water quality guidelines across North America and Europe do not protect lakes from salinization. Proc.Natl. Acad. Sci. U.S.A. 119:e2115033119, doi: 10.1073/pnas.2115033119
Isanta-Navarro, J., S. E. Arnott, T. Klauschies, and D. Martin-Creuzburg. 2021. Dietary lipid quality mediates salt tolerance of a freshwater keystone herbivore. Sci. Total Environ. 769: 144657.
Jeppesen, E., M. Søndergaard, A. R. Pedersen, K. Jürgens, A. Strzelczak, T. L. Lauridsen, and L. S. Johansson. 2007. Salinity induced regime shift in shallow brackish lagoons. Ecosystems 10:47-57.
Kaushal, S. S., G. E. Likens, M. L. Pace, R. M. Utz, S. Haq, J. Gorman, and M. Grese. 2018. Freshwater salinization syndrome on a continental scale. Proc. Natl. Acad. Sci. U. S. A. 115: E574–E583, doi:10.1073/pnas.1711234115
Loureiro, C., B. B. Castro, M. Teresa Claro, A. Alves, M. Arminda Pedrosa, and F. Gonçalves. 2012. Genetic variability in the tolerance of natural populations of Simocephalus vetulus (Müller, 1776) to lethal levels of sodium chloride. Ann. Limnol. – Int. J. Lim. 48: 95-103.
Moffett, E. R., H. K. Baker, C. C. Bonadonna, J. B. Shurin, and C. C. Symons. 2021. Cascading effects of freshwater salinization on plankton communities in the Sierra Nevada. Limnol. Oceanogr. Lett. n/a. doi:10.1002/lol2.10177
Venâncio, C., R. Ribeiro, A. M. V. M. Soares, and I. Lopes. 2018. Multigenerational effects of salinity in six clonal lineages of Daphnia longispina. Sci. Total Environ. 619: 194-202.
Weider, L. J. and P. D. N. Hebert. 1987. Ecological and physiological differentiation among low-Arctic clones of Daphnia pulex. Ecology 68.1: 188-198.
Dugan, H. A., S. L. Bartlett, S. M. Burke, J. P. Doubek, F. E. Krivak-Tetley, N.K. Skaff, J. C. Summers, K. J. Farrell, I. M. McCullough, A. M. Morales-Williams, D. C. Roberts, Z.Ouyang, F. Scordo, P. C. Hanson, and K.C. Weathers. 2017. Salting our freshwater lakes. Proc. Natl. Acad. Sci. U. S. A. 114.17: 4453-4458.
Elphick J. F., K. D. Bergh, and H. C. Bailey. 2011. Chronic toxicity of chloride to freshwater species: effects of harness and implications for water quality guidelines. Environ. Toxicol. Chem. 30:239-246.
Greco, D. S.E. Arnott, I. Fornier, B. Schamp. 2021. Effects of chloride and nutrients on freshwater zooplankton communities. Limnology and Oceanography Letters.
Herbert, E. R., P. Boon, A. J. Burgin, S. C. Neubauer, R. B. Franklin, M. Ardon, K. N. Hopfensperger, L. P. M. Lamers, and P. Gell. 2015. A global perspective on wetland salinization: ecological consequences of a growing threat to freshwater wetlands. Ecosphere 6:206
Hintz, W. D., B. M. Mattes, M. S. Schuler, D. K. Jones, A. B. Stoler, L. Lind, and R. A. Relyea. 2017. Salinization triggers a trophic cascade in experimental freshwater communities with varying food-chain length. Ecol. Appl. 27: 833–844, doi:10.1002/eap.1487
Hintz, W. D. and R. A. Relyea. 2019. A review of the species, community, and ecosystem impacts of road salt salinisation in fresh waters. Freshwater Biol. 64: 1081–1097, doi:10.1111/fwb.13286
Hintz, W. D., S. E. Arnott, C. C. Symons, D. A. Greco, A. McClymont, J. A. Brentrup, M. Cañedo-Argüelles, A. M. Derry, A. L. Downing, D. K. Gray, S. J. Melles, R. A. Relyea, J. Rusak, C. L. Searle, L. Astorg, H. K. Baker, B. E. Beisner, K. L. Cottingham, Z. Ersoy, C. Espinosa, J. Franceschini, A. T. Giorgio, N. Göbeler, E. Hassal, M.-P. Hébert, M. Huynh, S. Hylander, K. L. Jonasen, A. E. Kirkwood, S. Langenheder, O. Langvall, H. Laudon, L. Lind, M. Lundgren, L. Proia, M. S. Schuler, J. B. Shurin, C. F. Steiner, M. Striebel, S. Thibodeau, P. Urrutia-Cordero, L. Vendrell-Puigmitja, G. A. Weyhenmeyer. Current water quality guidelines across North America and Europe do not protect lakes from salinization. Proc.Natl. Acad. Sci. U.S.A. 119:e2115033119, doi: 10.1073/pnas.2115033119
Isanta-Navarro, J., S. E. Arnott, T. Klauschies, and D. Martin-Creuzburg. 2021. Dietary lipid quality mediates salt tolerance of a freshwater keystone herbivore. Sci. Total Environ. 769: 144657.
Jeppesen, E., M. Søndergaard, A. R. Pedersen, K. Jürgens, A. Strzelczak, T. L. Lauridsen, and L. S. Johansson. 2007. Salinity induced regime shift in shallow brackish lagoons. Ecosystems 10:47-57.
Kaushal, S. S., G. E. Likens, M. L. Pace, R. M. Utz, S. Haq, J. Gorman, and M. Grese. 2018. Freshwater salinization syndrome on a continental scale. Proc. Natl. Acad. Sci. U. S. A. 115: E574–E583, doi:10.1073/pnas.1711234115
Loureiro, C., B. B. Castro, M. Teresa Claro, A. Alves, M. Arminda Pedrosa, and F. Gonçalves. 2012. Genetic variability in the tolerance of natural populations of Simocephalus vetulus (Müller, 1776) to lethal levels of sodium chloride. Ann. Limnol. – Int. J. Lim. 48: 95-103.
Moffett, E. R., H. K. Baker, C. C. Bonadonna, J. B. Shurin, and C. C. Symons. 2021. Cascading effects of freshwater salinization on plankton communities in the Sierra Nevada. Limnol. Oceanogr. Lett. n/a. doi:10.1002/lol2.10177
Venâncio, C., R. Ribeiro, A. M. V. M. Soares, and I. Lopes. 2018. Multigenerational effects of salinity in six clonal lineages of Daphnia longispina. Sci. Total Environ. 619: 194-202.
Weider, L. J. and P. D. N. Hebert. 1987. Ecological and physiological differentiation among low-Arctic clones of Daphnia pulex. Ecology 68.1: 188-198.
