Gulf of Alaska | Fishes and Fish Habitats
Combined effects of ocean warming and acidification on Pacific cod early life stages Presenter: Thomas Hurst , thomas.hurst@noaa.gov, NOAA Fisheries Alaska Fisheries Science Center
Emily Slesinger , emily.slesinger@noaa.gov, Alaska Fisheries Science Center Samantha Mundorff , smundorff@gmail.com, Northeastern University Ben Laurel , ben.laurel@noaa.gov, NOAA Alaska Fisheries Science Center
The North Pacific is simultaneously experiencing ocean warming (OW) and ocean acidification (OA), which may negatively impact the early life stages of important fish species. Pacific cod ( Gadus macrocephalus ) is an important commercial fisheries species with demonstrated sensitivity to OA and OW, but their combined impacts are unknown. Through a 5-week long experiment, we reared Pacific cod eggs and larvae at three temperatures (3, 6, 10C) and two CO2 levels (ambient: ~400utm; high: ~1700uatm) in a factorial design. Embryo and larval mortality was highest at 10C, and there was lower mortality in the high CO2 treatment at the embryo stage. Length and mass-specific growth was faster as temperature warmed; high CO2 led to faster growth at an early stage of development, but this effect diminished at a later stage of development. There were significant interactive effects of temperature and OA on condition of myotome height (deviance in myotome height at a specific length). Fish in highest condition were observed at 6C at ambient CO2, while fish in the 3C treatment were overall in the lowest condition, but those in the ambient CO2 were in lower condition than in the high CO2 treatment. Overall, temperature tended to have a dominant effect on Pacific cod, with nuanced effects of CO2 as a single and interactive stressor. These results show the complexity of stage- and trait-specific responses to co-occurring climate stressors, and the importance of investigating the effects of OW and OA in combination.
Alaska Marine Science Symposium 2023 199
Made with FlippingBook flipbook maker