copepod title

Synopsis

The ocean is quickly becoming warmer and acidified (CO2-richer, lower pH). The consequences of this simultaneous warming and acidification on populations of marine organisms are neither fully known nor understood. Hence, our ability to forecast the response of populations to these changes is severely hampered at the moment, particularly because of the lack of experimental work that considers more than a few generations. This project will determine, for the first time, how two closely related species of copepods (the most abundant animals in the oceans) with different potential for evolutionary thermal adaptation will respond to the interactive effects of warming and acidification, and whether these effects are mitigated by evolutionary adaptation. The proposed work, which combines measurements of phenotypic, genetic and epigenetic responses to global change conditions across multiple generations, is likely to provide novel insights into adaptation to thermal- and CO2-related stress, and emerging properties that lead to adaptability.

The project will provide training and excellent opportunities for collaborative, interdisciplinary research for two postdoctoral investigators, two Ph.D. students and an undergraduate student.

The project’s main goals are:

  1. To test the simultaneous effects of temperature and CO2 under current and future conditions on life history traits, throughout the life cycle, of two keystone copepod species, Acartia tonsa (warm-adapted) and Acartia hudsonica (cold-adapted).
  2. To test for adaptive capacity of both copepod species to a warmer and CO2-richer ocean.
  3. To measure the genetic and maternally induced changes across multiple generations of experimental selection in future conditions in both copepod species, and to identify the genes and pathways responding to selection.

Experiments, which include combinations of mean current and projected (end of 21st century) temperature and CO2 conditions (4 combinations in total), will determine the respective roles of each variable and their interaction on traits that affect the fitness (ability to leave offspring) of both copepod species. The experiments will also allow one to determine which life stages o are most sensitive to individual or simultaneous stress conditions of temperature and CO2. The mechanisms of copepod evolutionary adaptation will be identified and characterized through multigenerational selection experiments (10 generations for each species). Genomic changes across the generations will be measured in all four experimental conditions to quantify the relative contributions of genetic and maternally induced change in the critical physiological and life history traits of copepods in response to near future climate conditions.

Current and former grants:

  • Dam, H. Baumann, H. and Finiguerra, M. Predicting the performance of the copepod Acartia tonsa under future conditions of temperature and CO2. Connecticut Sea Grant College Program ($149,969 2 years)
  • Dam, H. Baumann, H. and Pespeni, M. Collaborative Research: Transgenerational phenotypic and genomic responses of marine copepods to the interactive effects of temperature and CO2 NSF #1559180 ($609,684 3 years)

NSF outcomes report (public)

Over time, our oceans are becoming both warmer and higher dissolved carbon dioxide. The latter condition is called ocean acidification. The consequences of these simultaneous changes for populations of marine organisms are not well understood.

For this project, the investigators conducted a series of laboratory experiments to determine how two closely-related, common species of Acartia copepods respond to the interactive effects of warming and acidification and also how well these species can adapt over multiple generations to changing ocean conditions.

Since these copepods are key species in coastal food webs, results will have important implications for understanding and predicting how marine ecosystems may respond to future climate change. The investigators will share results from the research through traditional print media, case studies, and video mini lectures. The goal will be for educators of all levels to easily access material on climate change and ocean acidification to include in teaching curricula, in alignment with recommendations for universal design for learning.

The project is a collaborative effort between an established professor at the University of Connecticut and an early-career female scientist at the University of Vermont. It will provide training and opportunities for collaborative, interdisciplinary research for two postdoctoral investigators, two graduate students and an undergraduate student.

The project's main goals were:

1) to test the simultaneous effects of temperature and carbon dioxide under current and future conditions on life history traits throughout the life cycle for two key copepod species, warm-adapted Acartia tonsa and cold-adapted Acartia hudsonica;
2) to test for adaptive capacity of both copepod species to a warmer and carbon-dioxide-enriched ocean;
3) to measure the genetic and maternally-induced changes across multiple generations of experimental selection in future conditions in both copepod species, and to identify the genes and pathways responding to selection.

The investigators used experiments encompassing current and projected temperature and carbon-dioxide conditions, determined the roles of each variable and their interaction on traits that affect the fitness of both copepod species. They also determined which life stages are most sensitive to individual or simultaneous stress conditions.

Through multigenerational selection experiments, the investigators identified and characterized the mechanisms of copepod evolutionary adaptation. Finally, they will measure genomic changes across the generations under all four experimental conditions to quantify the relative contributions of genetic and maternally-induced change in the physiological and life history traits of copepods in response to near-future climate conditions.

PUBLICATIONS PRODUCED AS A RESULT OF THIS RESEARCH

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Sasaki, M., Hedberg, S., Richardson, K., & Dam, H. G. "). Complex interactions between local adaptation, developmental phenotypic plasticity, and sex affect vulnerability to warming in a widespread marine copepod" Royal Society Open Science , v.6 , 2019 10.1098/rsos.182115

Aguilera, V.M., C.A. Vargas and H.G. Dam "Antagonistic interplay between pH and food affect traits and performance of a dominant copepod in a year-round upwelling system" Scientific Reports , v.10 , 2020 https://doi.org/10.1016/j.pocean.2019.102241

Besiktepe, S. and H.G. Dam. "Effect of diet on the coupling of ingestion and egg production in the ubiquitous copepod, Acartia tonsa" Progress In Oceanography , 2020 https://doi.org/10.1016/j.pocean.2020.102346.

Sasaki, M., H.G. Dam "Integrating patterns of thermal tolerance and phenotypic plasticity with population genetics to improve understanding of vulnerability to warming in a widespread copepod" Global Change Biology , v.25 , 2019 , p.4147-4164 https://doi.org/10.1111/gcb.14811

Aguilera, V.M., C.A. Vargas and H.G. Dam. "Antagonistic interplay between pH and food affect traits and performance of a dominant copepod in a year-round upwelling system." Scientific Reports (Nature) , v.10 , 2019 , p.62 https://doi.org/10.1038/s41598-019-56621-6

Besiktepe, S*. and H.G. Dam. "Effect of diet on the coupling of ingestion and egg production in the ubiquitous copepod, Acartia tonsa." Progress in Oceanography , v.186 , 2020 , p.102346 https://doi.org/10.1016/j.pocean.2019.102241

Dam, H.G., J.A. deMayo, G. Park*, L. Norton, X. He, M.B. Finiguerra, H. Baumann, R.S. Brennan and M. H. Pespeni. "2021. Rapid, but limited, adaptation of marine zooplankton to simultaneous warming and acidification." Nature Climate Change , v.11 , 2021 , p.780 https://doi.org/10.1038/s41558-021-01131-5

deMayo,J.A., A. Girod, M. Sasaki, and H.G. Dam. "Adaptation to simultaneous warming and acidification carries a thermal tolerance cost in a marine copepod." Biology Letters , v.17 , 2021 , p.20210071. https://doi.org/10.1111/gcb.14811

Sasaki, M. and H.G. Dam. "Integrating patterns of thermal tolerance and phenotypic plasticity with population genetics to improve understanding of vulnerability to warming in a widespread copepod." Global Change Biology , v.25 , 2019 , p.4147 https://doi.org/10.1111/gcb.14811

Sasaki, M. and H.G. Dam. "Genetic differentiation underlies seasonal variation in thermal tolerance, body size, and phenotypic plasticity in a short-lived copepod." Ecology and Evolution , v.10 , 2020 , p.12200 https://doi.org/10.1002/ece3.6851

Sasaki, M. and H.G. Dam. "Negative relationship between thermal tolerance and plasticity in tolerance emerges during experimental evolution in a widespread marine invertebrate. 1" Evolutionary Applications , v.14 , 2021 , p.2114 https://doi.org/10.1111/eva.13270

Sasaki, M. and H.G. Dam. 2021 "Global patterns in copepod thermal tolerance. J. Plankton Res." Journal of Plankton Research , v.43 , 2021 , p.598 https://doi.org/10.1093/plankt/fbab044

Sasaki, M., S. Hedberg, K. Richardson, and H.G. Dam "Complex interactions between local adaptation, developmental phenotypic plasticity, and sex affect vulnerability to warming in a widespread marine copepod." Royal Society Open Science , v.6 , 2019 , p.182115 https://doi.org/10.1098/rsos.182115

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