Seawater carbonate chemistry and hatching rate, malformation rate, metamorphosis rate and shell growth of the Pacific abalone in a laboratory experiment

The hatching process of the Pacific abalone Haliotis discus hannai was prolonged at a pH of 7.6 and pH 7.3, and the embryonic developmental success was reduced. The hatching rate at pH 7.3 was significantly (10.8%) lower than that of the control (pH 8.2). The malformation rates at pH 7.9 and pH 8.2 were less than 20% but were 53.8% and 77.3% at pH 7.6 and pH 7.3, respectively. When newly hatched larvae were incubated for 48 h at pH 7.3, only 2.7% of the larvae settled, while more than 70% of the larvae completed settlement in the other three pH treatments. However, most 24 h old larvae could complete metamorphosis in all four pH treatments. Overall, a 0.3-unit reduction in water pH will produce no negative effect on the early development of the Pacific abalone, but further reduction in pH to the values predicted for seawater by the end of this century will have strong detrimental effects.

太平洋皱纹盘鲍（Haliotis discus hannai）的孵化过程在pH 7.6与pH 7.3条件下出现延长，胚胎发育成功率亦有所降低。pH 7.3条件下的孵化率较对照组（pH 8.2）显著降低10.8%。pH 7.9与pH 8.2条件下的畸形率均低于20%，而pH 7.6与pH 7.3条件下的畸形率分别为53.8%与77.3%。将刚孵化的幼体在pH 7.3条件下培育48小时后，仅2.7%的幼体完成附着，其余三个pH处理组中超过70%的幼体均完成附着。但在所有四个pH处理组中，孵化24小时的幼体大多可完成变态发育。总体而言，水体pH降低0.3个单位不会对太平洋皱纹盘鲍的早期发育产生负面影响，但若将pH进一步降低至本世纪末海水pH的预测值，则会产生强烈的有害影响。