EAPSI: Determining the Response of Migratory Fish to Environmental and Climatic Variability

这项研究将与奥塔哥大学的鱼类洄游专家Gerard Closs博士合作完成，并将确定影响鱼类洄游成功的因素和条件。这项研究的影响，可以广泛地了解的因素，在迅速变化的环境和气候条件下，这将是决定未来的人口动态的基础，往往受到威胁，洄游鱼类，并将提供这些受威胁的人口的保护和管理的影响。气候变化可以影响淡水和海洋水生系统中的营养物质，从而影响迁徙生物在这两种环境之间的成功迁移，这称为跃层现象。此外，河流流量可能受到气候/环境变化的影响，直接影响到迁徙个体的成功。在这项研究中，我们将评估气候过程，如厄尔尼诺现象，如何影响水流和海洋和淡水营养物质的可用性，以确定是否迁移成功的影响，在两个洄游鱼类，Gobiomorphus cotidianus和Galaxias argentius。这项研究将评估从代表不同溪流流量和营养生产力的溪流中收集的样本，并将使用中分辨率成像分光仪卫星图像来确定海洋环境中营养供应的变化如何影响迁移成功。气候变化可以影响淡水和海洋系统的生产力，影响这些系统之间的水生移民的成功（即，二分体）。迁移的成功率可能会随着环境条件的变化而波动，如河流流量或生产力。这项研究的主要假设是气候变化（即，厄尔尼诺现象）改变了移民和居民的成功，影响河流流量制度和海洋和淡水生产力，采样两个溯河产卵物种，Gobiomorphus cotidianus和Galaxias argentius沿着河流流量和生产力梯度。耳石微结构和微化学分析将用于确定在不同气候条件下个体从淡水流迁移到海洋环境的速率（厄尔尼诺/南方涛动指数）。MODIS卫星图像将用于分析沿海生产力对养分/生产力梯度上迁移倾向的影响，而土地利用/土地变化卫星图像将用作溪流生产力的代表，以确定陆地养分梯度上的迁移率动态。 该奖项是东亚和太平洋暑期研究所项目下的一个奖项，由NSF和新西兰皇家学会共同资助，用于支持美国研究生的暑期研究。

This research will be completed in collaboration with leading fish migration expert, Dr. Gerard Closs at the University of Otago, and will identify factors and conditions influential to the success of migration in fishes. The implications of this study can be drawn broadly to understand the factors that influence migratory species under rapidly changing environmental and climatic conditions which will be foundational in determining future population dynamics of, often threatened, migratory fishes and will provide information for conservation and management of these threatened populations. Climate variability can influence the nutrients available in freshwater and marine aquatic systems which can subsequently affect the success of migratory organisms to move between those two environments, called diadromy. Additionally, stream flow can be influenced by climatic/environmental variability directly influencing the success of migratory individuals. In this study, we will evaluate how climatic processes, like El Niño, affect stream flow and marine and freshwater nutrient availability to determine if migration success is influenced in two migratory fish species, Gobiomorphus cotidianus and Galaxias argentius. This study will evaluate samples collected from streams representative of varying stream flow and nutrient productivity and will use MODIS satellite images to determine how changes in nutrient availability in the marine environment might influence migration success. Climate variability can affect the productivity of freshwater and marine systems influencing the success of aquatic migrants between those systems (i.e., diadromy). Migratory success can fluctuate in response to variable environmental conditions such as stream flow or productivity. The primary hypothesis of this study is that climate variation (i.e., El Niño) alters the success of migrants and residents by affecting stream flow regimes and marine and freshwater productivity by sampling two diadromous species, Gobiomorphus cotidianus and Galaxias argentius along stream flow and productivity gradients. Otolith microstructure and microchemistry analysis will be used to determine the rate at which individuals migrate from freshwater streams to marine environments under different climatic conditions (ENSO index). MODIS satellite images will be used to analyze the influence of coastal productivity on migration propensity across a nutrient/productivity gradient while land use/land change satellite imagery will be used as proxy for stream productivity to determine migration rate dynamics across a terrestrial nutrient gradient. This award, under the East Asia and Pacific Summer Institutes program, supports summer research by a U.S. graduate student and is jointly funded by NSF and the Royal Society of New Zealand.