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，在海鲜市场上通常售价数千或数百万美元。由于极度受欢迎，该物种已被过度捕捞，近几十年来人口减少了96%。尽管经历了急剧下降，但太平洋蓝鳍金枪鱼的迁移模式以及这种迁移发生的生命阶段仍然是未知的。本研究将透过分子分析来探讨太平洋蓝鳍吞拿鱼洄游的速率。这项研究将由水产研究所与台湾大学海洋研究所教授、长期从事长嘴鱼等远洋鱼类研究的孙继禄博士合作，利用稳定同位素分析技术，进一步了解太平洋蓝鳍金枪鱼（PBFT）在北太平洋的洄游规律。在不同的海洋区域，当地的海洋条件影响三角洲-15 N值的基础上的食物网（浮游植物），这些差异传播的食物网从浮游生物到猎物的掠食者。以前的研究表明，东太平洋和西太平洋（EPO和WPO）之间的基线δ-15 N存在差异。由于这些差异，PBFT可以根据低（居民）或高（移民）δ-15 N值分类为WPO中的居民或最近移民。 通过分析来自WPO的PBFT样本，将对移民模式进行推断，包括确定西部居民和东部移民的规模等级。这个NSF EAPSI奖是与台湾国家科学理事会合作资助的。

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.