Effects of elevated carbon dioxide on Pacific cod larvae size and behavior from laboratory experiment studies from 2015-02-12 to 2016-07-02 (NCEI Accession 0202775)

This dataset contains data from a multi-faceted analysis of the sensitivity of Pacific cod larvae to elevated carbon dioxide (CO2) levels based on laboratory experiment studies. Fish behavior in a horizontal light gradient was used to evaluate the sensitivity of behavioral phototaxis in 4–5 week old cod larvae. Fish at elevated CO2 levels (~1500 and 2250 μatm) exhibited a stronger phototaxis (moved more quickly to regions of higher light levels) than fish at ambient CO2 levels (~600μatm). In an independent experiment, we examined the effects of elevated CO2 levels on growth of larval Pacific cod over the first 5 weeks of life under two different feeding treatments. Fish exposed to elevated CO2 levels (~1700μatm) were smaller and had lower lipid levels at 2 weeks of age than fish at low (ambient) CO2 levels (~500μatm). However, by 5 weeks of age, this effect had reversed: fish reared at elevated CO2 levels were slightly (but not significantly) larger and had higher total lipid levels and storage lipids than fish reared at low CO2. Fatty acid composition differed significantly between fish reared at high and low CO2 levels (p less than 0.01) after 2 weeks of feeding, but this effect diminished by week 5. Effects of CO2 on FA composition of the larvae differed between the two diets, an effect possibly related more to dietary equilibrium and differential lipid class storage than a fundamental effect of CO2 on fatty acid metabolism. These experiments point to a stage-specific sensitivity of Pacific cod to the effects of OA. Further understanding of these effects will be required to predict the impacts on production of Pacific cod fisheries.