How will copepods cope with marine climate change?
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:
- 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).
- To test for adaptive capacity of both copepod species to a warmer and CO2-richer ocean.
- 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)