Collaborative Research: Possible Climate-induced Change in the Distribution of Pleuragramma Antarcticum on the Western Antarctic Peninsula Shelf.

智力价值：南极银鱼Pleuragramma antarcticum在南极沿海生态系统的营养金字塔中扮演着关键角色，充当较大的鱼、会飞的和不会飞的海鸟、鳍脚类和鲸鱼的食物。反过来，它们又是沿海真甲虫的捕食者，包括超级真甲虫和结晶藻。从历史上看，Pleuragramma一直是南极半岛西部Adélie企鹅的重要食物来源，但在过去十年中，Pleuragramma已经从Adélie饮食中消失。我们认为，Pleuragramma？S在顶级捕食者的食物中的缺失与海冰覆盖率的下降有关，在南半球的春季，海冰是卵和幼虫的托儿所。这项研究将调查WAP大陆架上的四种水文状况，其特征如下：(1)持续的漩涡水流，以留住当地产卵的幼体；(2)近年来春季海冰的减少；(3)成年银鱼的流行；以及(4)繁殖的Adélie企鹅的存在，它们的食物与食用的银鱼的比例不同。这项研究将通过对鱼类的种群结构、耳石微化学和分子遗传学的分析，评估局部繁殖与幼体平流的重要性，以及研究区域内种群在遗传上的差异程度。Pleuragramma的数据将与同义采集的企鹅饮食样本进行比较。更广泛的影响：拟议的研究汇集了一个国际科学家小组，他们拥有高度互补的技能套件，以解决WAP货架上Pleuragramma的命运。研究生将使用获得的数据作为他们博士研究的一部分，并将接受鸟类学领域技术、分子遗传学方法和耳石同位素化学的交叉培训。PIS将积极与《圣彼得堡时报》合作，制作一个实时的带有图片和文字的博客，用于在我们出海和返回后与当地学校互动。调查人员还将与USF的COSEE中心以及当地学校和博物馆合作，将结果传播给整个地区的K-12社区。

Intellectual Merit: Pleuragramma antarcticum, the Antarctic silverfish, play a key role in the trophic pyramid of the Antarctic coastal ecosystem, acting as food for larger fishes, flying and non-flying seabirds, pinnipeds, and whales. In turn, they are predators on coastal euphausiids, including both Euphausia superba and crystallorophias. Historically, Pleuragramma have been an important food source for Adélie Penguins of the Western Antarctic Peninsula (WAP), but during the last decade Pleuragramma have disappeared from the Adélie diet. We suggest that Pleuragramma?s absence from the diets of top predators is linked to the declining sea ice canopy, which serves as a nursery for eggs and larvae during the austral spring. The research will investigate four hydrographic regimes over the WAP continental shelf with the following features: (1) persistent gyral flows that act to retain locally spawned larvae, (2) spring sea ice that has declined in recent years (3) the prevalence of adult silverfish, and (4) the presence of breeding Adélie penguins whose diets vary in the proportions of silverfish consumed. The research will evaluate the importance of local reproduction versus larval advection, and the extent to which populations in the subregions of study are genetically distinct, via analysis of population structure, otolith microchemistry and molecular genetics of fish. The Pleuragramma data will be compared with penguin diet samples taken synoptically. Broader Impacts: The proposed research brings together an international group of scientists with highly complimentary suites of skills to address the fate of Pleuragramma on the WAP shelf. Graduate students will use the data acquired as part of their Ph.D research, and will receive cross-training in ornithological field techniques, molecular genetic methods and otolith isotope chemistry. The PIs will work actively with the St. Petersburg Times to produce a blog in real time with pictures and text, which will be used to interact with local schools while we are at sea and after our return. The investigators also will collaborate with the COSEE center at USF and at local schools and museums to disseminate results to the K-12 community throughout the region.