Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
  • BCO-DMO Processing Description
• Data Files
• Related Publications
• Related Datasets
• Parameters
• Instruments
• Project Information
• Funding

Three hundred copepods were collected in April of 2018 from eastern Long Island Sound, Connecticut, USA (41.3°N, 72.0°W) and raised for one year (~12 generations) (14 degrees Celsius (°C), 400 microatmospheres (μatm) CO2, 30 ‰ salinity, 12:12 hours light:dark) as stock cultures to limit maternal effects (Falconer, 1989, Introduction to Quantitative Genetics). Three resulting stock cultures with >2,000 individuals each were combined and then split evenly into three groups for each of the four treatments. Groups were acclimatized within a generation to temperature (15°C or 13°C, 1°C per day) and pCO2 (1000 μatm, 100 μatm per day, OA treatments only). Groups seeded the F0 individuals for 7-10 days yielding ~15,000 eggs per treatment. Resulting F0 eggs and nauplii were combined for each treatment, redistributed among three replicate cultures, and returned to their respective experimental conditions. The experimental environmental conditions were: 1) Ambient control (AM): 13°C, 400 µatm CO2, pH = 8.2; 2) Ocean Acidification (OA): 13°C, 1000 µatm CO2, pH = 7.85; 3) Ocean Warming (OW): 15°C, 400 μatm CO2, pH = 8.2; 4) Combined warming and acidification (OWA): 15°C, 1000 μatm CO2, pH = 7.85. Copepods were fed equal proportions of the live phytoplankters Tetraselmis sp., Rhodomonas sp., and Thalassiosira weissflogii every 48-72 hours to achieve food-replete conditions (≥600 micrograms (μg) Carbon per liter (L)) (Feinberg and Dam, 1998. Marine Ecology Progress Series), deliberately raised under ambient conditions to avoid confounding effects of possible food quality changes.

Survival was measured from nauplius 1 (N1) to copepodid 6 (C6; adult). For a given generation, all adults from the previous generation were removed from the culture and allowed to lay eggs in food-replete media for 48 hours. Resulting nauplii were chosen for tracking survival. Unhatched eggs and any nauplii not chosen for survival analysis were returned to their respective cultures for continued population maintenance. To measure survival, three 250 milliliter (mL) beakers for each replicate culture were supplied with 25 randomly chosen N1 nauplii each and housed in the plexiglass enclosure (n= 9 per treatment). Copepods were checked every 48-72 hours. The number of dead, live, and missing copepods was recorded for each beaker along with developmental stage (nauplius, copepodite, adult female, or adult male). Nauplii were grown with media at levels of 250 μg C L-1 for the first four days to prevent overgrowth of phytoplankton and allow for adequate nauplii grazing. Then, copepods were grown with food-replete media. For food limitation experiments in F11, the three beakers for each replicate culture were split evenly between the three food concentrations. Food media was replaced on monitoring days. Average survival probabilities were calculated for each replicate culture at each generation as the proportion of surviving individuals on monitoring days.

The fraction of survived individuals (lx) was calculated as (nx /ni) where nx represents the number of live individuals on day x, and ni represents initial individuals. Average survival was calculated per each replicate culture at each generation measured. Differences in day-specific survival between replicates and treatments were assessed using the 'survival' package in R (v 4.0.2).

- Imported original file "Survival_data_total.txt" into the BCO-DMO system.
- Renamed fields to comply with BCO-DMO naming conventions.
- Saved final file as "924088_v1_a_hudsonica_survival.csv".

NSF Award Abstract:
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 will conduct a series of laboratory experiments to determine how two closely-related, common species of Acartia copepods will 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 are: 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 will use experiments encompassing current and projected temperature and carbon-dioxide conditions, will determine the roles of each variable and their interaction on traits that affect the fitness of both copepod species. They will also determine which life stages are most sensitive to individual or simultaneous stress conditions. Through multigenerational selection experiments, the investigators will identify and characterize 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.