Increasing CO₂ levels in the surface water of oceans are expected to decrease oceanic pH and lead to seawater acidification. The responses of macroalgaea to this acidification of coastal waters have been studied in detail; however, most reports have focused on the adult stage only, while ignoring other life cycle stages. In this study, the economically important seaweed species Pyropia yezoensis was cultured under two CO₂ concentrations (ambient CO₂: 400 μatm; elevated CO₂: 1000 μatm) and two light intensities (low light intensity: 80 μmol photons m⁻² s⁻¹; and high light intensity: 240 μmol photons m⁻² s⁻¹). The effects on the growth and photosynthetic performance of P. yezoensis were explored at different life cycle stages. Relative growth rates were significantly elevated at the conchocelis stage under high light intensity and elevated CO₂ concentration. Moreover, the P_max of P. yezoensis was also increased under high light intensity. However, this positive effect inversed at the thallus stage. The relative growth rate, relative electron transport rate (rETR), and net photosynthetic rate decreased at the thallus stage in response to high CO₂ concentration. Under low light intensity, elevated CO₂ concentration significantly increased the relative growth rates of conchocelis and thallus stages. These were 269% and 45% higher at elevated CO₂ concentration compared with ambient CO₂ concentrations, respectively. The Chl a and phycoerythrin levels were also higher under elevated CO₂ level at the conchocelis stage. However, the rETR for the thallus stage was elevated under low light. This suggests that seawater acidification could positively affect algae at low light conditions (especially at the conchocelis stage). Different growth stages of P. yezoensis may respond differently to seawater acidification and changes of light intensity. Thalli growth stage, stocking density, and seawater depth should be considered in different areas to optimize the primary production of macroalgae.

预计海洋表层水中CO ₂含量的增加会降低海洋的pH值并导致海水酸化。大型藻类对沿海水体酸化的反应已被详细研究。但是，大多数报告只关注成年阶段，而忽略了其他生命周期阶段。在这项研究中，经济上重要的海藻种类Pyropia条斑紫菜的混合物在2个CO培养₂浓度（环境CO ₂：400μatm;升高CO ₂：1000μatm）和两个光强度（低光强度：80微摩尔光子中号^-2 小号^{- 1}；高光强度：240μmol光子m ^-2  s ^-1）。在不同的生命周期阶段，研究了对野牛假单胞菌的生长和光合性能的影响。在高光强度和升高的CO ₂浓度下，在眼镜蛇阶段的相对生长速度显着提高。此外，在高光强度下，紫叶假单胞菌的P _max也增加。但是，这种积极的作用在失速阶段相反。响应于高CO ₂浓度，在all茎阶段相对生长速率，相对电子传输速率（rETR）和净光合速​​率降低。在低光强度下，CO ₂升高浓度显着提高了耳蜗和all体阶段的相对生长速率。这些较高269％和45％在升高的CO ₂浓度与周围相比CO ₂浓度，分别。在菜豆期，在CO ₂升高的情况下，Chl a和藻红蛋白水平也较高。然而，在弱光下，all体阶段的rETR升高。这表明海水酸化可在弱光条件下（特别是在贝壳菌阶段）对藻类产生积极影响。yezoensis的不同生长阶段对海水酸化和光强度变化的反应可能不同。应在不同地区考虑塔里的生长阶段，放养密度和海水深度，以优化大型藻类的初级生产。