Do oceanographic characteristics and predator-prey behaviours define critical marine habitats?

我们如何管理海洋的角色正在迅速变化。过去的方法是单一物种管理，缺乏许多环境方面的因素，也没有渔业的直接投入。这种方法被发现是不可行的，许多种群被以不可持续的水平捕捞。未来的道路是认识到我们需要使用基于生态系统的方法进行管理，同时在管理决策中保持与渔业的直接互动。这样的生态系统方法需要更机械性地理解物理环境所起的作用，同时也要考虑到多种物种的相互作用。同样清楚的是，随着对我们海洋系统的空间利用提出更多的需求(即近海可再生发展、海洋保护区和捕捞活动在空间上得到更多的管理)，更好地了解海洋栖息地的作用至关重要。这尤其困难，因为海洋生物栖息地可以在空间和时间上移动。然而，任何渔民都可以告诉你，有一些地方(和时间)几乎总是比其他地方更好的捕获物。理解为什么会出现这种情况是一个根本性的挑战。在北海和凯尔特海涉及PI和Co-PI的早期研究中，我们发现，在海鸟、海洋哺乳动物或捕捞活动不成比例高的地方，也有空间有限的高水平次表层初级生产量的斑块。这些斑块似乎与地形驱动的内波有关，其物理效应可能导致初级生产力的局部增加和较小海洋生物的物理聚集。因此，这些特征可能是由于整个食物链中的复杂联系而导致的可预测的觅食区域(假设A)，或者只是增强了捕食者在这些位置捕获猎物(鱼)的能力(假设B)。这些区域的水下特征意味着，在确定了重要的表面特征的研究中，它们被忽视了，例如已知含有许多海洋物种聚集体的热锋。因此，这些斑块代表了一类新确定的浅海空间上重要的位置。在这个项目中，我们建议使用一个新的调查框架来检验假设A和B之间的关系，该框架结合了所有这些因素，并确定了海洋栖息地的关键特征，在那里更有可能发生多物种(捕食者-猎物)相互作用和渔业作业。这一调查框架在某种程度上是基于渔民几个世纪以来一直使用的久经考验的方法：即观察海鸟和海洋哺乳动物的行为，以此作为渔场位置的指南。我们的目标是通过海洋生态学家(U.Aberdeen)、生物和物理海洋学家(POL)、法定机构(FRS、CEFAS、JNCC)以及渔民(CFPO)和一系列熟练的海洋动物和渔业观察员(JNCC、MRAG)之间的多学科方法来推进这一做法。该项目也是一个独特的机会，可以更充分地利用NERC海洋2025项目。在这种跨学科的方法中，我们将把将在海洋2025计划中研究的连续的物理和生物海洋学特征与声学声纳后向散射、海鸟和海洋哺乳动物的视觉观察、鲸目动物的发声、渔业观察以及更长期的渔业和海洋动物调查数据的额外收集结合在一起。通过这些组合数据产品，我们将识别和定义这些亚表面斑块的特征，以及可能导致促进捕食者-猎物相互作用的生物物理机制。这项研究将大大加强实施可持续渔业管理的生态系统办法所需的机械性理解。

The role of how we manage our seas is changing rapidly. The past approach was that of single species management, devoid of many environmental aspects, and without direct input from the fishing industry. That approach has been found wanting with many stocks fished at unsustainable levels. The way forward has been to recognise that we need to manage using an ecosystem based approach while at the same time maintaining direct interaction with the fishing industry in management decisions. Such an ecosystem approach requires a more mechanistic understanding of the role the physical environment plays whilst also taking into account multiple species interactions. It is also clear, as more demand is put upon the space use of our marine systems (i.e. offshore renewable developments, Marine Protected Areas and fishing effort becomes managed more on a spatial basis), a better understanding of the role of marine habitat is essential. This is particular difficult as marine habitat can move in both space and time. However, any fisherman can tell you that there are some locations (and times) that are almost always better than others for good catches. The understanding as to why that may be is a fundamental challenge. In earlier studies involving both the PI and Co-PI, in the North and Celtic Seas, we have found that in locations where there are disproportionately high numbers of seabirds, marine mammals or fishing effort, there are also spatially limited patches of high levels of sub-surface primary production. The patches appear to be associated with topographically-driven internal waves whose physical effects may be responsible for localised increases of primary production and the physical aggregation of smaller marine organisms. Therefore these features could be responsible for the predicable areas of foraging due to complex links in the entire food web (Hypothesis A) or just enhance the ability of predators to capture prey (fish) in these locations (Hypothesis B). The sub-surface signature of these areas has meant that they have been overlooked in studies which have identified important surface features, such as thermal fronts, known to contain aggregations of many marine species. These patches therefore represent a newly-identified class of spatially important locations in shallow seas. In this project we propose to test between Hypothesis A & B using a new survey framework that incorporates all of those factors and defines the critical characteristics of the marine habitat where multi-species (predator-prey) interactions and fisheries operations are more likely to occur. This survey framework is based, to some degree, on the tried and tested method that fishermen have used for centuries: i.e. to observe seabird and marine mammal behaviour as a guide to locations of fishing grounds. Our aim is to take that practice forward with a multi-disciplinary approach between marine ecologists (U. Aberdeen), biological and physical oceanographers (POL), statutory agencies (FRS, CEFAS, JNCC) as well as fishermen (CFPO) and a range of skilled marine animal and fisheries observers (JNCC, MRAG). This project also represents a unique opportunity, to more fully utilise a NERC Oceans2025 Project. In this interdisciplinary approach we will combine the continuous physical and biological oceanographic features that will be studied in the Oceans2025 program with the additional collection of acoustic sonar backscatter, visual observations of seabirds and marine mammals, vocalisations of cetaceans, fishery observations, and longer term fisheries and marine animal survey data. With these combined data products, we will identify and define the characteristics of these sub-surface patches and the bio-physical mechanisms that may lead to the facilitation of predator-prey interactions. This research will greatly enhance the type of mechanistic understanding needed for implementing the ecosystem approach to sustainable fisheries management.