Data from: Ocean acidification alters the response of intertidal snails to a key sea star predator

Organism-level effects of ocean acidification (OA) are well recognized. Less understood are OA's consequences for ecological species interactions. Here, we examine a behaviourally mediated predator–prey interaction within the rocky intertidal zone of the temperate eastern Pacific Ocean, using it as a model system to explore OA's capacity to impair invertebrate anti-predator behaviours more broadly. Our system involves the iconic sea star predator, Pisaster ochraceus, that elicits flee responses in numerous gastropod prey. We examine, in particular, the capacity for OA-associated reductions in pH to alter flight behaviours of the black turban snail, Tegula funebralis, an often-abundant and well-studied grazer in the system. We assess interactions between these species at 16 discrete levels of pH, quantifying the full functional response of Tegula under present and near-future OA conditions. Results demonstrate the disruption of snail anti-predator behaviours at low pH, with decreases in the time individuals spend in refuge locations. We also show that fluctuations in pH, including those typical of rock pools inhabited by snails, do not materially change outcomes, implying little capacity for episodically benign pH conditions to aid behavioural recovery. Together, these findings suggest a strong potential for OA to induce cascading community-level shifts within this long-studied ecosystem.

海洋酸化（Ocean Acidification）对生物体层面的影响已得到广泛认可。但学界对OA如何影响生态物种间相互作用的认知仍较为匮乏。本研究选取温带东太平洋潮间带岩礁生境中一类由行为介导的捕食者-猎物相互作用作为模型系统，以此探究OA更广泛地损伤无脊椎动物抗捕食行为的潜力。该模型系统的捕食者为标志性的赭石海星（Pisaster ochraceus），其可诱发多种腹足类猎物产生逃逸反应。本研究重点关注OA引发的pH值降低能否改变黑瘤滨螺（Tegula funebralis）的逃逸行为——该物种是该生境中常见且被广泛研究的牧食者。我们设置16个梯度的pH值开展物种相互作用实验，量化了当前及近未来OA场景下黑瘤滨螺的完整功能响应。实验结果表明，低pH环境会破坏螺类的抗捕食行为，表现为个体在避难场所停留的时间缩短。此外研究发现，pH波动——包括螺类栖息的岩池典型pH波动——并不会显著改变实验结果，这意味着间歇性的温和pH条件对螺类行为恢复的帮助极为有限。综合来看，本研究结果表明OA极有可能在这个被长期研究的潮间带生态系统中引发级联式的群落结构变化。