EAPSI: Elucidating migration patterns of Pacific Bluefin Tuna using molecular analysis of stable isotopes

太平洋蓝鳍金枪鱼是一种重要的商业渔业物种，在海鲜市场上的售价往往高达数千或数百万美元。由于极度流行，该物种遭到严重过度捕捞，近几十年来种群数量下降了96%。尽管经历了戏剧性的下降，太平洋蓝鳍金枪鱼的整个太平洋的迁徙模式以及发生这种迁徙的生命阶段仍然未知。这项研究将通过分子分析来研究太平洋蓝鳍金枪鱼的迁徙速度。这项研究将在水产研究所与台湾大学海洋研究所教授孙志路博士合作进行，他在研究长吻鱼和其他中上层物种方面有很长的历史。这个项目将使用稳定同位素分析来更好地了解北太平洋的太平洋蓝鳍金枪鱼(PBFT)的迁徙模式。在不同的海洋区域，当地的海洋条件影响食物网(浮游植物)底部的Delta-15N值，这些差异从浮游生物到猎物再到捕食者，沿着食物网向上传播。以前的研究表明，东太平洋和西太平洋(EPO和WPO)的基线三角洲-15N之间存在差异。由于这些差异，PBFT可以根据低(居民)或高(移民)三角洲-15N值被归类为WPO的居民或最近移民。通过分析来自世界卫生组织的PBFT样本，将对移民模式做出推断，包括识别不同大小阶层的西部居民和东部移民。这项NSF EAPSI奖是与台湾国家科学委员会合作资助的。

Pacific bluefin Tuna are an important commercial fisheries species, often sold for thousands or millions of dollars in seafood markets. Due to extreme popularity, the species has been greatly overfished, and experienced declines in population of 96% in recent decades. Even though dramatic declines have been experienced, the migration patterns across the Pacific, as well as the life stages in which this migration happens is still unknown for the Pacific bluefin Tuna. This study will investigate the rate of Pacific bluefin Tuna migration through molecular analysis. This research will be conducted at the Fisheries Research Institute in collaboration with Dr. Chi-Lu Sun, who has a long history of research on billfish and other pelagic species as professor at National Taiwan University's Institute of Oceanography.This project will use stable isotope analysis to better understand Pacific bluefin tuna (PBFT) migration patterns in the North Pacific Ocean. In different ocean regions, local oceanographic conditions affect delta-15N values at the base of the food web (phytoplankton), and these differences propagate up food webs from plankton to prey to predators. Previous studies have demonstrated differences in baseline delta-15N between the eastern and western Pacific Ocean (EPO and WPO). Because of these differences, PBFT can be categorized as residents or recent migrants in the WPO based on low (resident) or high (migrant) delta-15N values. By analyzing samples of PBFT from the WPO, inferences about migration patterns, including the identification of western residents and eastern migrants across a range of size classes will be made. This NSF EAPSI award is funded in collaboration with the National Science Council of Taiwan.