Seabirds and wind - the consequences of extreme prey taxis in a changing climate

由于温室气体排放导致全球气候变暖，构成生态系统的生物的分布和种群规模正在发生变化。例如，一些欧洲鸣禽正在向北扩大它们的活动范围，而另一些则在减少。这些影响不仅从物种保护的角度来看令人担忧，而且因为健康的生态系统为人类提供了至关重要的服务。例如，植物产生我们呼吸的氧气，昆虫为植物授粉，使食物生产成为可能。因此，迫切需要预测生物对气候变化的反应，以便能够有效和及时地减轻这些反应。我提议的研究项目涉及一种可能特别容易受到气候变化影响的动物：信天翁、海燕和海鸥（或简称为“海燕”）。这些大到中等大小的海鸟因其远距离飞行寻找食物的能力而引人注目。例如，大海鸥每年都会穿越赤道，这使它们能够利用夏季北大西洋和南大西洋食物丰富的高峰期。与其他大型捕食者，如鲸鱼和鲨鱼一样，进食的海燕聚集在所谓的热点地区，这是由海洋环流模式造成的。海燕能够在这些热点地区和它们的繁殖地之间快速飞行，因为它们能够利用风飞行。然而，这意味着它们的运动受到盛行风模式的限制：就像古老的帆船一样，它们需要避开逆风和平静的区域。据预测，随着全球变暖，全球风的模式将发生显著变化。例如，“马纬度”的风速预计将会下降，而温带地区的风速将会增加。“马纬度”是亚热带地区的一条微风带。与此同时，随着海洋变暖，海燕赖以为生的鱼类、鱿鱼和甲壳类动物的分布预计会向两极转移。虽然这些变化可能对一些海燕有益，但也可能对其他海燕有害。例如，在迁徙过程中，大海鸥可能会在海洋中部停滞不前，那里食物稀缺，饥饿的可能性很高。这些影响可能会产生更广泛的影响，因为海燕像植物和昆虫一样，提供了一些重要的生态系统服务。例如，通过在它们的栖息地中沉积富含营养的鸟粪，它们支持了一些岛屿上的整个生态系统。人们对海洋中的相关机制知之甚少，但对与海燕饮食相似的大型鲸鱼的研究提供了一些线索：他们认为，通过回收或运输营养物质，海鸟刺激了浮游植物的生长，浮游植物是一种微小的绿藻，构成了海洋食物金字塔的基础。浮游植物也很重要，因为它们从大气中吸收二氧化碳，减缓气候变化的速度。尽管气候变化给海燕带来了威胁，但我们对它们生活的了解仍有很大的差距。迄今为止，对这些物种的大多数研究都是在非常偏远的地区进行的，比如围绕南极洲的南大洋。相比之下，值得注意的是，人们对大西洋深处海燕的生活知之甚少，尽管这片海洋被世界上一些最发达的国家所包围。因此，我的研究目的是把大西洋作为一个实验室，以确定海燕是如何受到最近气候变化的影响的；它们如何影响浮游植物生长和二氧化碳水平；以及它们如何应对未来的气候变化。我将通过使用微型记录器和船上采样记录海燕的运动、行为和饮食来实现这一目标。然后，我将使用计算机模型，将这些数据与风、海洋条件和海燕种群变化的数据结合起来，以预测未来海燕的运动、种群规模和生态系统服务将如何变化。

As the world's climate warms due to the emission of greenhouse gases, the distribution and population sizes of the organisms that make up ecosystems are changing. For example, some European songbirds are expanding their ranges northwards, while others are declining. These effects are of concern not only from a species conservation perspective but because healthy ecosystems provide services vital to humanity. For example, plants produce the oxygen we breathe and insects pollinate plants, enabling food production. As such, there is an acute need to forecast the responses of organisms to climate change so that they can be mitigated in an effective and timely manner.My proposed fellowship concerns one group of animals that may be particularly vulnerable to climate change: albatrosses, petrels and shearwaters (or simply, 'petrels'). These large-to-medium sized seabirds are remarkable for their ability to fly vast distances in search of food. For example, great shearwaters migrate across the equator each year, allowing them to exploit summertime peaks in food abundance in both the North and South Atlantic. Along with other large predators, like whales and sharks, feeding petrels congregate in so called hotspots caused by the ocean circulation patterns. Petrels are able to travel rapidly between these hotspots and their breeding colonies because of their ability to use the wind to fly. This, however, means that their movements are limited by prevailing wind patterns: Like the sailing ships of old, they need to avoid headwinds and areas of calm. Global wind patterns are forecast to change markedly as the world warms. For example, wind speeds in the 'horse latitudes', a belt of already light winds in the sub-tropics, are predicted to decline, while those at temperate latitudes will increase. At the same time, as the oceans warm, the distribution of the fish, squid and crustaceans that petrels feed on is predicted to shift towards the poles. While these changes could benefit some petrels, they may harm others. For example, during migration, great shearwaters could become becalmed in mid-ocean, where food is scarce and the chances of starvation high.These impacts may have wider implications because, like plants and insects, petrels provide some important ecosystem services. For example, by depositing nutrient-rich guano in their colonies they support entire ecosystems on some islands. Less is known about related mechanisms in the sea but studies on large whales, which have similar diets to petrels, give some clues: They suggest that by recycling or transporting nutrients, seabirds stimulate the growth of phytoplankton, the tiny green algae that form the base of the marine food pyramid. Phytoplankton are also important because they draw carbon dioxide out of the atmosphere, slowing the rate of climate change.Despite the threats posed to petrels by climate change there are some large gaps in our understanding of their lives. To-date, the majority of research on these species has been carried out in very remote areas, like the Southern Ocean, which surrounds Antarctica. In contrast, remarkably, little is known about the lives of petrels in the deep Atlantic, despite the fact that this ocean is bounded by some of the world's most developed nations. The aim of my fellowship is therefore to use the Atlantic as a laboratory in order to determine how petrels have been affected by recent changes in the climate; how they affect phytoplankton growth and carbon dioxide levels; and how they may respond to future climate change. I will achieve this by recording the movement, behaviour and diet of petrels at sea using miniature loggers and ship-based sampling. I will then combine these data, using computer models, with data on wind and ocean conditions and petrel population changes, in order to predict how petrel movements, population sizes and ecosystem services will change in the future.