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.

本数据集涵盖基于实验室实验开展的多维度分析数据，旨在探究太平洋鳕幼体对二氧化碳（CO₂）浓度升高的敏感性。实验通过水平光梯度下的鱼类行为表现，评估4~5周龄太平洋鳕幼体的行为趋光性（behavioral phototaxis）敏感性：相较于环境CO₂浓度组（约600μatm），暴露于升高CO₂浓度（约1500、2250μatm）的幼体展现出更强的趋光性，即更快移动至高光照区域。在另一项独立实验中，我们设置两种不同投喂处理，探究CO₂浓度升高对太平洋鳕幼体出生后前5周生长状况的影响。幼体2周龄时，暴露于升高CO₂浓度（约1700μatm）组的个体体型更小、脂质水平低于低CO₂浓度组（约500μatm，即环境浓度）；但至5周龄时，该效应出现逆转：高CO₂浓度组幼体体型略大于低CO₂浓度组（差异无统计学显著性），且总脂质与储存脂质水平更高。投喂2周后，高、低CO₂浓度组幼体的脂肪酸组成存在显著差异（p<0.01），但该差异在第5周时消失。CO₂对幼体脂肪酸组成的影响因投喂日粮不同而存在差异，该效应可能更多与日粮平衡及脂质类别储存差异相关，而非CO₂对脂肪酸代谢的根本性直接影响。上述实验表明，太平洋鳕对海洋酸化（Ocean Acidification，OA）的敏感性存在发育阶段特异性。若要预测海洋酸化对太平洋鳕渔业产量的影响，尚需进一步阐明此类效应的内在机制。