Impacts of anthropogenic noise on reproduction and survival

自工业革命以来，城市化、交通运输和资源开发等产生噪音的人类活动有所增加，并改变了陆地和水生生态系统的声学景观。人为噪音现已被认为是环境变化的一个主要因素，也是一种受到国际关注的污染物；例如，它被列入欧盟委员会海洋战略框架指令（MSFD）和美国国家环境政策法案，并作为国际海事组织环境议程的永久项目。鱼类可以利用自然的声音进行交流、定位和栖息地选择，但我们知道，人为的噪音会提高它们的压力水平，影响交流、觅食和运动。然而，很难预测这对个体适应性（生存和繁殖）以及种群和群落意味着什么。我们最近的工作表明，短期暴露在摩托艇噪音中会影响鱼类的反捕食行为，导致在遇到天然捕食者时死亡率增加一倍，但到目前为止，我们还不知道长期暴露在噪音中如何影响其他关键的生活史过程。该项目的目的是利用已建立的实地研究系统（珊瑚礁鱼）来评估人为噪音的主要来源（摩托艇）对具有直接适应性和生态影响的关键生活史过程（繁殖、胚胎和幼虫存活）的影响。我们将驾驶船只在棘鱼Acanthochromis polyacanthus和Ambon雀鲷Pomacentrus amboinensis的巢穴周围，评估所产生的噪音对繁殖和早期生存的影响。随后对圈养繁殖种群的实验将使我们能够区分噪音暴露对父母、胚胎和幼虫对后代生长和死亡的相对影响。使用唯一可识别的应答器，详细的现场观察和对蛋捕食者的实验操作，将使我们能够确定船只噪音如何影响父母照顾蛋和守卫巢穴的表现，以及对生殖输出的后果。在21世纪，关注珊瑚礁鱼类尤为重要，因为它们赖以生存的珊瑚礁是全球受威胁最严重的海洋生态系统之一，但它们为25%的鱼类提供了栖息地，并支持着养活5亿人口和1亿人生计的渔业，这些渔业往往生活在世界上最贫穷的国家。我们会测试汽艇噪音的影响，主要有两个原因。首先，因为沿海地区正在经历前所未有的人口增长，沿海娱乐和旅游业显著增加，包括划船（例如，美国注册的汽艇1250万艘，预计到2040年大堡礁将有50万艘船）。其次，由于在珊瑚礁的自然和人工栖息地附近驾驶船只是可行的，我们可以进行精心控制的实验，这在后勤上对其他海洋人为噪音来源（例如打桩和航运）更具挑战性。我们将与海洋管理人员、船用发动机制造商、旅游和渔业经营者以及保护机构合作，测试现代四冲程船用发动机是否比传统二冲程发动机的影响更小，并确定每种发动机类型的影响范围。我们的研究将直接为未来的船舶发动机设计提供信息，并为制定大堡礁以及欧洲和美国水域的噪音管理计划提供急需的证据。

Noise-generating human activities, such as urbanisation, transportation and the exploitation of resources, have increased since the Industrial Revolution and have changed the acoustic landscape of terrestrial and aquatic ecosystems. Anthropogenic (man-made) noise is now recognised as a major component of environmental change and a pollutant of international concern; for example, it is included in the European Commission Marine Strategy Framework Directive (MSFD) and the US National Environment Policy Act, and as a permanent item on the environmental agenda of the International Maritime Organization.Fish can use natural sounds for communication, orientation and habitat selection, but we know that anthropogenic noise can raise their stress levels and affect communication, foraging and movement. However, it is difficult to predict what this might mean for individual fitness (survival and reproduction), and thus for populations and communities. Our recent work has shown that short-term exposure to motorboat noise can affect fish anti-predator behaviour, causing a doubling in mortality when encountering natural predators, but as yet we don't know how longer-term noise exposure affects other key life-history processes.The aim of this project is to use an established field-based study system (coral reef fish) to assess the impacts of a major source of anthropogenic noise (motorboats) on key life-history processes (reproduction, embryonic and larval survival) that have direct fitness and ecological implications. Driving boats around nests of the spiny chromis Acanthochromis polyacanthus and the Ambon damselfish Pomacentrus amboinensis, we will assess the impacts of the generated noise on reproduction and early-life survival. Subsequent experiments with captive-breeding populations will allow us to separate the relative effects of noise exposure on parents, embryos and larvae for offspring growth and mortality. Use of uniquely identifiable transponders, detailed field observations and experimental manipulations of egg predators will enable us to determine how boat noise affects the performance of parents tending eggs and guarding nests, and the consequences for reproductive output.Focussing on coral reef fish is especially important in the 21st Century as the reefs upon which they depend are among the most globally threatened marine ecosystems, yet they provide habitat for 25% of all fish species, and support fisheries that feed 0.5 billion people and the livelihoods of 100s millions, often in the world's poorest countries. We will test impacts of noise generated by motorboats for two main reasons. First, because coastal regions are experiencing unprecedented human population growth, with a significant rise in coastal recreation and tourism, including boating (e.g. 12.5 million registered powerboats in the USA, 0.5 million boats predicted for the Great Barrier Reef by 2040). Second, because it is feasible to drive boats near to natural and manipulated habitats on coral reefs, we can conduct carefully controlled experiments that are logistically far more challenging with other sources of marine anthropogenic noise (e.g. pile-driving and shipping).We will work in partnership with marine managers, boat-engine manufacturers, tourism and fishing operators, and conservation agencies to test whether modern four-stroke boat engines have less impact than traditional two-stroke engines, and determine the zone of impact for each engine type. Our research will directly inform future boat-engine design, and provide much-needed evidence for developing management plans for noise on the Great Barrier Reef and in European and US waters.