English  |  正體中文  |  简体中文  |  Items with full text/Total items : 28588/40619
Visitors : 4199934      Online Users : 51
RC Version 4.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
Scope Adv. Search
LoginUploadHelpAboutAdminister

Please use this identifier to cite or link to this item: http://ntour.ntou.edu.tw:8080/ir/handle/987654321/53135

Title: 探討太平洋大目鮪成熟與未成熟群時空間分布與海洋環境變動之關係
Spatiotemporal variation of mature and immature bigeye tuna(Thunnus obesus) related to oceanographic and climatic indices in the Pacific Ocean
Authors: Lin, Tzu-Hsiang
林子翔
Contributors: NTOU:Department of Environmental Biology and Fisheries Science
國立臺灣海洋大學:環境生物與漁業科學學系
Keywords: 大目鮪;太平洋;泛加成模式;海洋環境變動;氣候變異
Bigeye tuna;Pacific Ocean;Generalized Additive Models;Environmental variations;Climate variability
Date: 2019
Issue Date: 2020-07-02T07:40:35Z
Abstract: 本研究彙整太平洋2002-2014年臺灣鮪延繩釣五度方格之漁獲資料及體長資料,將其中之大目鮪數據彙整區分成熟(≧3歲)及未成熟(<3歲)群,結合多衛星遙測演算水文環境資料(SST、SSH、SSS、MLD和CHL)以及氣候因子指數(ONI、PDO和NPGO),並利用GAM模式以探討大目鮪成熟與未成熟群分布、釣獲率變動與海洋環境間之關係。分析結果顯示,未成熟群主要分布在熱帶及北太平洋,而成熟群主要在赤道地區隨著海洋環境呈現季別變動。GAM模式中,未成熟群總解釋率為35.4%,成熟群解釋率為56.4%,而未成熟群單一環境因子解釋率最高者為SST (20%),其次為MLD(19.5%),第三則為SSH(16.2%)。而成熟群單一環境因子解釋率最高者為SST(33.4%),其次為MLD(24.2%),再次之則為CHL(22.8%)。另外大目鮪成熟與未成熟群具有相似的最適水文環境範圍,約介於SST 25-28℃、SSH 0.4-0.5m、SSS 34.5-35.5psu、MLD 50-100m和CHL 0.1-0.2 mg/m3,而3項氣候因子除了NPGO對成熟群釣獲率無顯著影響(成熟群p=0.154)外皆對釣獲率有顯著影響(p<0.05)。探討氣候因子與大目鮪釣獲率之關係則顯示其在ONI正值年時,受暖水團推移影響而導致釣獲率較佳;而ONI負值年時釣獲率則下降。另外PDO正事件時成熟與未成熟群釣獲率較佳,當PDO轉為負事件時,分析顯示因餌料生物(如浮游動物與仔稚魚)豐度下降導致未成熟群釣獲率下降,進而影響2~3年後成熟群的加入量,導致成熟群釣獲率亦呈現下降之趨勢。建議未來可加入其他國籍船隊資料進行整合分析,將可有效於在漁業管理中利用,以期盼達到漁業永續經營之目標。
The bigeye tuna (Thunnus obesus, BET) is one of the important commercial species for longline fisheries in Pacific Ocean. In this study, we collected the records of bigeye tuna catch rates, length data of longline fisheries and divided into immature and mature cohorts. We also collected the satellite-base oceanographic data of sea surface temperature (SST)、sea surface height (SSH)、sea surface salinity (SSS)、mixed layer depth (MLD) and chlorophyll-a concentration (CHL) and three climate indices including Oceanic Nino Index (ONI)、Pacific Decadal Oscillation (PDO) and North Pacific Gyre Oscillation (NPGO). The generalized additive models (GAMs) were used to investigate the relationships between environmental variables and catch rates for evaluating the fishing condition of the immature and mature cohorts of BET. The results showed the spatial distribution of the immature cohorts were concentrated in the central and northern Pacific Ocean, and the mature cohorts were shifted followed seasonal environment variations in the central Pacific Ocean. The GAMs model selection processes showed the cumulative deviances explained by selected GAMs were 35.4% and 56.4% for immature and mature cohorts, respectively. The results showed the catch rates of immature and mature cohorts had similar pattern and were significantly correlated with environmental variables of SST in the range 26-28℃, 0.1-0.2mg/m3 of CHL, 34.5-35.5 psu of SSS, 0.4-0.5 m of SSH, and 50-100 m of MLD. However, it is a similar result for immature and mature cohorts, the SST and MLD explained the highest deviance for both cohorts, but the SSH explained the third deviance for the immature cohorts, and CHL was revealed for the mature cohorts. The BET shows that the catch rates were increased due to the movement of the warm water mass in Pacific Ocean when the ONI was in positive events. In addition, in the negative PDO events, the abundance of BET food organism (zooplankton and ichthyoplankton) had decreased trends and influenced the lower recruitment of immature cohorts and catch rates of mature cohorts after 2-3 years.
URI: http://ethesys.lib.ntou.edu.tw/cgi-bin/gs32/gsweb.cgi?o=dstdcdr&s=G0010731008.id
http://ntour.ntou.edu.tw:8080/ir/handle/987654321/53135
Appears in Collections:[環境生物與漁業科學學系] 博碩士論文

Files in This Item:

File SizeFormat
index.html0KbHTML1View/Open


All items in NTOUR are protected by copyright, with all rights reserved.

 


著作權政策宣告: 本網站之內容為國立臺灣海洋大學所收錄之機構典藏,無償提供學術研究與公眾教育等公益性使用,請合理使用本網站之內容,以尊重著作權人之權益。
網站維護: 海大圖資處 圖書系統組
DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - Feedback