Trophic consequences of ocean acidification: Intertidal sea star predators and their grazer prey

人类制造的二氧化碳被吸收到世界海洋中，正在改变海水的化学成分，包括降低其ph值。这种变化统称为“海洋酸化”，预计将影响许多种类的海洋生物。该项目研究海洋pH值的变化如何影响动物行为，从而影响物种之间的相互作用。它使用了一个案例研究系统，涉及海星捕食者，它们吃的蜗牛食草动物，以及后者消耗的海藻。这些生物生活的岩岸栖息地长期以来受到关注，这项工作的新发现将进一步扩展已经很大的海洋生态知识体系。该项目为研究生和本科生提供支持，包括来自附近社区学院的代表性不足的学生。该项目支持为当地K-12学校开发新的教育模块。此外，调查结果将通过使用短片纪录片，以及通过与政策、管理和行业团体建立的关系，以及与媒体的联系，向公众传播。海洋酸化是一种全球范围的扰动。然而，关于这一主题的大多数研究都研究了对孤立运作的单个物种的影响，而物种之间的相互作用尚未得到充分探索。该项目通过考虑海洋酸化如何通过改变行为改变捕食者-猎物关系来解决这一知识差距。它的目标是作为模型系统的海星，它们的腹足类食草动物的猎物，以及后者消耗的海藻，通过四条调查线。1)该项目通过针对16个离散ph水平的实验，研究了焦点分类群对改变的海水化学的功能响应。这种实验设计对于识别非线性和临界点至关重要。2)该项目涉及直接和间接物种相互作用的消耗性和非消耗性成分。人们对海洋酸化影响这种联系的能力知之甚少，更好地了解这一问题是公认的优先事项。3)该项目将实验室控制实验与现场试验相结合，利用潮汐池及其独特的pH值特征作为自然生态系统。海洋酸化影响的实地试验相对较少，而且非常需要。4)最后一个研究阶段在上述三个组成部分的基础上进行扩展，以解决海洋酸化对在岩石潮间带系统中相互作用的多个其他分类群的影响，为将来的实验或建模提供一个广泛的数据库。

The absorption of human-produced carbon dioxide into the world's oceans is altering the chemistry of seawater, including decreasing its pH. Such changes, collectively called "ocean acidification", are expected to influence numerous types of sea creatures. This project examines how shifts in ocean pH affect animal behavior and thus interactions among species. It uses a case study system that involves sea star predators, snail grazers that they eat, and seaweeds consumed by the latter. The rocky-shore habitats where these organisms live have a long history of attention, and new findings from this work will further extend an already-large body of marine ecological knowledge. The project provides support for graduate and undergraduate students, including underrepresented students from a nearby community college. The project underpins the development of a new educational module for local K-12 schools. Findings will moreover be communicated to the public through the use of short film documentaries, as well as through established relationships with policy, management, and industry groups, and contacts with the media.Ocean acidification is a global-scale perturbation. Most research on the topic, however, has examined effects on single species operating in isolation, leaving interactions among species underexplored. This project confronts this knowledge gap by considering how ocean acidification may shift predator-prey relationships through altered behavior. It targets as a model system sea stars, their gastropod grazer prey, and macoalgae consumed by the latter, via four lines of inquiry. 1) The project examines the functional response of the focal taxa to altered seawater chemistry, using experiments that target up to 16 discrete levels of pH. This experimental design is essential for identifying nonlinearities and tipping points. 2) The project addresses both consumptive and non-consumptive components of direct and indirect species interactions. The capacity of ocean acidification to influence such links is poorly known, and better understanding of this issue is a recognized priority. 3) The project combines controlled laboratory experiments with field trials that exploit tide pools and their unique pH signatures as natural mesocosms. Field tests of ocean acidification effects are relatively rare and are sorely needed. 4) A final research phase expands upon the above three components to address effects of ocean acidification on multiple additional taxa that interact in rocky intertidal systems, to provide a broad database that may have utility for future experiments or modeling.