| Description |
Climate change is altering ocean chemistry and wind-driven upwelling regimes. In the California Current System (CCS), these changes are exposing nearshore fishes to increasing levels of high pCO2 and hypoxia. These stressors co-occur during upwelling events, lasting hours to days, and both have the potential to decrease energy budgets and shift individuals towards less efficient (anaerobic) pathways of ATP production. We assessed metabolic status in juvenile blue and gopher rockfish (Sebastes mystinus and S. carnatus), after exposure to acute high pCO2 and hypoxia conditions. We sampled white muscle, gill, and liver tissues from individuals at 12 hours and 2 weeks in order to capture the timescales of upwelling events in the CCS. We quantified the activities of anaerobic and aerobic metabolic enzymes (lactate dehydrogenase and citrate synthase) and total protein content at each time point to examine shifts in rockfish metabolism. We found little evidence of shifts towards anaerobic metabolism and no changes in total protein content at any timepoint (One-way ANOVA, p>0.05). However, we did find a significant effect of time on liver protein concentration between 12 hours and 2 weeks (Two-way ANOVA, p<0.05), suggesting a lab effect. Overall, these data suggest that juvenile blue rockfish are relatively resilient to the effects of high pCO2 and hypoxia. |
