Impact of Ocean Subsurface Vertical Thermal Structure on the Fishing Condition of Swordfish in the Atlantic Ocean

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簡歷

基本資料

Project title

Code/計畫編號

MOST107-2611-M019-011

Translated Name/計畫中文名

海洋次表層水溫垂直結構對大西洋劍旗魚漁況變動之影響

Project Coordinator/計畫主持人

Nan-Jay Su

Funding Organization/主管機關

National Science and Technology Council

Co-Investigator(s)/共同執行人

江偉全

Department/Unit

Department of Environmental Biology and Fisheries Science

Website

https://www.grb.gov.tw/search/planDetail?id=12667524

Year

2018

Start date/計畫起

01-08-2018

Expected Completion/計畫迄

31-07-2019

Bugetid/研究經費

914千元

ResearchField/研究領域

海洋科學

劍旗魚廣泛分布於三大洋海域，是大洋生態系重要頂級掠食者，亦是商業性鮪延繩釣漁業混獲魚種與休閒漁業目標漁獲對象，然而目前大西洋劍旗魚已處於過漁狀態，急需資源保育與漁業管理。劍旗魚棲息於300公尺以深水層，過去相關研究多在生物參數建立、分布洄游、漁場變動與資源指標分析，同時僅以海表層水文環境參數進行棲地分析，無法瞭解不同水層溫度對劍旗魚棲地利用的影響，以致有錯估釣獲率與漁獲壓力的潛在風險。本計畫預計蒐集彙整混合座標模式(HYCOM)分層水溫資料及其他海洋環境因子包括海表層水溫(SST)、混合層深度(MLD)、等溫層底深(TBD)、等溫層梯度(TTG)與深溫層梯度(DPG)等大尺度水文參數，以瞭解海洋次表層水溫垂直結構。同時蒐集大西洋台灣遠洋鮪釣漁業高解析1度別作業日誌資料，比較深層式與傳統鮪釣作業方式對劍旗魚漁況變動之影響，以準確評估水層溫度垂直結構的可能影響。本研究透過衛星遙測與模式演算之海洋次表層水文環境資料，預期建構大西洋劍旗魚時空與垂直分布之完整棲地模式，有助於劍旗魚資源保育利用及大西洋台灣鮪釣漁業管理與永續發展，並提供資源評估科學性基礎資料。 Swordfish, as an important apex predator in the pelagic ecosystem, are widely distributed in the three oceans. They are commercially important resources for tuna longline fisheries and bycatch species for recreational fisheries. However, the Atlantic swordfish sotck has been overfished, and conservation and fisheries management plans are needed. Swordfish inhabit in the waters below 300 m in deep. Past studies focus on biological parameters, distribution and migration, fishing grounds and abundance index. However, the habitat analyses are only based on oceanographic variables in the surface layer of the ocean, which is hard to fully understand the impact of vertical thermal structure on their habitat use and potentially leads to the estimates of catch rates and fishing presure biasely. Based on a layered structure of temperature fields from the hybrid coordinate ocean model (HYCOM), a vertical profile of ocean subsurface was collected and compiled in this study into several parameters: sea surface temperature (SST), mixed layer depth (MLD), thermocline bottom depth (TBD), thermocline temperature gradient (TTG), and deep layer gradient (DPG). Fishery logbook data on weekly 1-degree high resolution for the Taiwanese distant-water tuna longline fishery in the Atlantic Ocean were aggregated and used to evaluate the impacts of vertical thermal structure on the variation of swordfish fishing condition for deep set and traditional longline fisheries. Ocean subsurface environmental variables based on remote sensing and hydrological models will be used to develop an integrated spatial and vertical habitat model for conservation and sustainable use of swordfish resource and management of the Taiwanese tuna longline fishery with basic scientific data for stock assessment.

Keyword(s)

棲地利用
海洋次表層
水溫垂直結構
劍旗魚
大西洋
habitat use
ocean subsurface
vertical thermal structure
swordfish
Atlantic Ocean

DSpace CRIS

Impact of Ocean Subsurface Vertical Thermal Structure on the Fishing Condition of Swordfish in the Atlantic Ocean

基本資料

Description