College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, 201306, China; State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, Shandong, 266071, China; Laboratory for Marine Ecology and Environmental Science, Laoshan Laboratory, Qingdao, Shandong, 266237, China.
State Key Laboratory of Mariculture Biobreeding and Sustainable Goods, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, Shandong, 266071, China; Laboratory for Marine Ecology and Environmental Science, Laoshan Laboratory, Qingdao, Shandong, 266237, China.
Mar Environ Res. 2023 Nov;192:106209. doi: 10.1016/j.marenvres.2023.106209. Epub 2023 Sep 26.
A 45-day trial was conducted to study the effect of seawater total alkalinity (TA) level up- and downregulation on the growth performance and calcification of Haliotis discus hannai Ino, while seawater pH was maintained at pH = 8.1. Although seawater was not acidified, the results showed that TA downregulation caused a significant reduction (P < 0.05) in the somatic tissue growth of juvenile abalone, while TA upregulation significantly increased growth performance (P < 0.05). Similar to the impacts of pH reduction, TA downregulation also induces a decline in CO buffering capacity, which may be the reason why somatic tissue growth was reduced, as lowered CO buffering capacity was reported to shift the acid-base balancing of abalone. Parts of the periostracum layer weremissing and exposed the inner shell layers of the individuals from the TA-downregulated group. Scanning electron microscopy (SEM) results showed calcium carbonate densely deposited onto the inner shell in the control and TA-upregulated groups, while sparsely deposited calcium carbonate was observed in the TA-downregulated group. The C: N ratio in the shell of individuals from the TA-downregulated group was significantly lower than that of the other two groups, indicating that less inorganic carbon was added to the shell. As a result, abalone grew lighter and thinner shells in TA-downregulated seawater. Although seawater was not acidified, TA downregulation also caused a reduction in the calcium carbonate saturation state (Ω), which induced the erosion of the surface shell and the interruption of calcium carbonate generation. In conclusion, although seawater pH remained at ambient levels, the lowered CO buffering capacity and Ω induced by seawater TA downregulation also showed a detrimental effect on the growth and calcification of Pacific abalone. The impact of ocean acidification on the growth of abalone should not be assessed using only seawater pH and/or pCO but rather taking into account all of carbonate chemistry, particularly the CO buffering capacity. Abalone cultivation is suggested to be carried out in seawater with a higher level of CO buffering capacity and Ω, which can be achieved through integrated culture with seaweed or increasing the seawater TA level.
进行了为期 45 天的试验，研究了海水总碱度（TA）水平的上调和下调对皱纹盘鲍（Haliotis discus hannai Ino）生长性能和钙化的影响，同时保持海水 pH 值为 pH = 8.1。尽管海水没有酸化，但结果表明 TA 下调导致幼鲍体组织生长显著减少（P < 0.05），而 TA 上调则显著提高了生长性能（P < 0.05）。与 pH 降低的影响类似，TA 下调也会导致 CO 缓冲能力下降，这可能是体组织生长减少的原因，因为据报道降低 CO 缓冲能力会改变鲍的酸碱平衡。TA 下调组的部分贝壳外层缺失，暴露出内层贝壳层。扫描电子显微镜（SEM）结果显示，对照组和 TA 上调组的贝壳内层有密集的碳酸钙沉积，而 TA 下调组则观察到稀疏的碳酸钙沉积。TA 下调组贝壳中的 C：N 比值明显低于其他两组，表明贝壳中添加的无机碳较少。因此，在 TA 下调的海水中，鲍鱼生长出更轻、更薄的贝壳。尽管海水没有酸化，但 TA 下调也导致碳酸钙饱和度（Ω）降低，从而导致表面贝壳的侵蚀和碳酸钙生成的中断。总之，尽管海水 pH 值保持在环境水平，但海水 TA 下调导致的 CO 缓冲能力和 Ω 降低也对太平洋鲍的生长和钙化产生了不利影响。评估鲍鱼生长对酸化的影响不应仅使用海水 pH 值和/或 pCO ，而应考虑所有碳酸盐化学特性，特别是 CO 缓冲能力。建议在 CO 缓冲能力和 Ω 较高的海水中进行鲍鱼养殖，可以通过与海藻综合养殖或提高海水 TA 水平来实现。
