Ocean acidification (OA) can induce changes in marine organisms and species interactions. We examined OA effects on intertidal macroalgal growth, palatability, and consumption by a specialist crab (Pugettia producta) and a generalist snail (Tegula funebralis) herbivore. Moderate increases in pCO₂ increased algal growth in most species, but effects of pCO₂ on C:N and phenolic content varied by species. Elevated pCO₂ had no effect on algal acceptability to herbivores, but did affect their preference ranks. Under elevated pCO₂, electivity for a preferred kelp (Egregia menziesii) and preference rankings among algal species strengthened for both P. producta and T. funebralis, attributable to resilience of E. menziesii in elevated pCO₂ and to changes in palatability among less-preferred species. Preferred algae may therefore grow more under moderate pCO₂ increases in the future, but their appeal to herbivores may be strengthened by associated shifts in nutritional quality and defensive compounds in other species.

海洋酸化（OA）会引起海洋生物和物种相互作用的变化。我们研究了 OA 对潮间带大型藻类生长、适口性以及一种专门蟹 ( Pugettiaproducta ) 和一种通才蜗牛 ( Tegula funebralis ) 草食动物的消耗的影响。 p CO ₂的适度增加会促进大多数物种的藻类生长，但p CO ₂对 C:N 和酚类含量的影响因物种而异。 p CO ₂升高对草食动物的藻类可接受性没有影响，但确实影响了它们的偏好等级。在p CO ₂升高的情况下， P.producta和T. funebralis的首选海带（ Egregia menziesii ）的选择性和藻类物种之间的偏好排名均得到加强，这归因于E. menziesii在p CO ₂升高中的恢复能力以及适口性的变化。不太受欢迎的物种。因此，未来在适度的p CO ₂增加下，优选的藻类可能会生长得更多，但它们对食草动物的吸引力可能会因其他物种中营养质量和防御化合物的相关变化而增强。