NSFGEO-NERC Collaborative Research: Effects of a changing climate on the habitat utilization, foraging ecology and distribution of crabeater seals

我们建议调查的营养生态，分布和觅食成功的螃蟹海豹跨越纬度梯度沿着南极洲西部半岛（wAP）的差异。由于全球气候变化和局部环境过程，大气和海洋沿着wAP正在迅速变化。我们的研究将提高我们的能力，了解整个依赖磷虾的大型捕食者群落将如何应对预计的环境变化。此外，我们有20年前的生态基线数据，包括该物种的运动模式、潜水行为、摄食行为、分布和丰度，以及20世纪90年代中期的历史数据和样本，为我们提供了一个独特的机会和有利的位置，以检测这种引人注目的南极中型捕食者和扩大捕食者群落的生态变化。Lobodon carcinophaga是南极沃茨的重要捕食者。这是由于其高度的生态专业化，大丰度和生物量，以及高代谢需求。它对单一猎物资源的高度依赖，加上是浮冰的强制性居民，使蟹海豹成为研究磷虾分布变化以及整个生态系统结构潜在变化的优秀物种：海豹的水平分布由磷虾的分布决定，同样，海豹的潜水行为也为了解这种磷虾在水柱中的垂直分布提供了线索。鉴于在日常栖息地的crabeater密封的要求二分法，我们的目标是评估这些以前重叠的栖息地是否现在分离的时间和空间沿着南极西部半岛。由于海冰形成时间和范围的纬度差异。以及极端依赖磷虾的食蟹海豹，我们预计，在北方wAP的个人已经修改了他们的觅食行为，并招致在升高的能量成本，而不是在南部wAP的动物。另外，食蟹海豹可能已经改变了他们的栖息地使用模式和/或他们的饮食，以应对气候变化沿着wAP.我们将使用传统的航空调查结合新技术（无人机和卫星图像），通过与BAS的合作，在wAP的海豹人口普查。航空测量将提供一个基准，我们可以根据该基准验证从这些平台获得的新数据，这些平台在后勤上更容易，更具成本效益。跟踪研究还将提供关于食蟹海豹的拖出模式的同步数据，这些数据将用于校正海上个体比例的调查数据1。调查和跟踪数据将首先用于确定螃蟹海豹的数量是否已经下降和/或向南移动，以应对海冰的减少。其次，开发物种分布的栖息地模型，以定义影响动物在哪里进食与它们在哪里外出的变量，确定这些栖息地如何不同，并预测这些环境条件的时空共存。

We propose to investigate the differences in the trophic ecology, distribution and foraging success of crabeater seals across a latitudinal gradient along the western Antarctica Peninsula (wAP). As a consequence of global climate change and local environmental processes, the atmosphere and oceans along the wAP are rapidly changing. Our study will enhance our ability to understand how the entire krill-dependent community of large predators will respond to the projected environmental changes. Furthermore, we have ecological baseline data from 20 years ago on movement patterns, diving behavior, feeding behavior, distribution and abundance for the species, as well as historical data and samples from the mid-1990s, providing us with a unique opportunity and advantageous position to detect changes in the ecology of this conspicuous Antarctic mesopredator and the extended predator community.The crabeater seal (Lobodon carcinophaga) is the most important predator of Antarctic krill Euphausia superba in Antarctic waters. This is due to its high degree of ecological specialization, large abundance and biomass, and high metabolic demand. Its high dependence on a single prey resource, combined with being an obligate inhabitant of the pack ice, makes the crabeater seal an excellent species to examine changes in krill distribution as well as potential changes in the structure of the entire ecosystem: the horizontal distribution of the seal is determined by the distribution of krill, and similarly the seals diving behavior provides insights into the vertical distribution of this euphausiid in the water column. Given the dichotomy in the daily habitat requirements of the crabeater seal, we aim to evaluate whether these previously-overlapping habitats are now separating in time and space along the western Antarctic Peninsula. Given the latitudinal differences in sea ice timing and extent. As well as the extreme dependence of crabeater seals on krill, we expect that individuals in the northern wAP have modified their foraging behavior and incur in elevated energetic costs as opposed to animals in the southern wAP. Alternatively, crabeater seals could have modified their habitat usage patterns and/or their diet in response to the changing climate along the wAP.We will use traditional aerial surveys combined with new technologies (UAS and satellite imagery) to census the population of seals in the wAP through a collaboration with BAS. The aerial surveys will provide a benchmark against which we can validate the new data obtained from these platforms, which are logistically easier and more cost-effective. The tracking studies will also provide concurrent data on haulout patterns of crabeater seals that will be used to correct the survey data for the proportion of individuals at sea1. The survey and tracking data will be utilized to first determine if the crabeater seal population has declined and or moved south in response to declining sea ice. Second, develop habitat models of the species distribution to define the variables that influence where the animals are eating versus where they are hauling out, determine how these habitats differ and predict the spatio-temporal co-occurrence of these environmental conditions.