氣候變遷對北大西洋海洋洄游魚種的潛在影響研究：以大西洋鱈魚、大西洋比目魚、大西洋鮭魚與大西洋藍鰭鮪魚為例

Abstract

隨著全球氣候變遷的影響，海洋環境亦受到相當程度的改變，北大西洋海域中環境因子長期的變化趨勢包含：海洋溫度、鹽度逐漸上升、海表面葉綠素甲濃度逐漸下降。面對生活環境的轉變，可能會造成生活於其中之生物改變生活型態，甚至會導致其數量之增減。本研究使用聯合國糧食與農業組織的全球捕獲量資料與全球簡易海洋資料同化分析系統的再分析資料，透過經驗正交函數分析法，分析1991年至2010年間海洋洄游魚種大西洋鱈魚、大西洋比目魚、大西洋鮭魚以及大西洋藍鰭鮪魚主要分布區域內環境因子的變異程度，並與目標魚種的捕獲量進行相關性比對。研究結果顯示在過去二十年間，海洋溫度的變化趨勢與大西洋鱈魚和大西洋鮭魚的捕獲量之間呈現顯著的高度負相關，大西洋鱈魚和大西洋藍鰭鮪魚的捕獲量與海洋鹽度的變化趨勢亦呈現顯著的高度負相關，海表面葉綠素甲濃度改變也可能影響大西洋比目魚、大西洋鮭魚和大西洋藍鰭鮪魚的捕獲量。此外環境鹽度的變化可能使得大西洋鱈魚改變原先習慣的生存深度轉往更深的水層生活，大西洋鮭魚也可能受到環境溫度的改變而將生活深度向下延展。由此可見，氣候變遷引發海洋環境發生變化並對於各個目標魚種有著不同程度的影響性。The ocean environment has changed in recent decades under the impacts of climate change. In the North Atlantic Ocean, the long-term trend of ocean temperature and salinity is increasing, whereas trend of chlorophyll-a concentration is decreasing. Owing to the changes in the living environment, we wonder how the environmental changes influence the marine organisms and how marine organisms adapt to the changes of environment. In this study, we use the global capture production data from FAO and the assimilation data from SODA POP to investigate the potential connections between the ocean environmental changes and the selected Atlantic fishes: Atlantic Cod, Atlantic Halibut, Atlantic Salmon, and Atlantic Bluefin Tuna during the period 1991-2010 based on the empirical orthogonal function analysis. Our results indicate a significant negative correlation between the ocean temperature and the capture productions of Atlantic Cod and Atlantic Salmon over the past two decades. The relationship between the capture productions of Atlantic Cod and Atlantic Bluefin Tuna and the ocean salinity shows significant negative correlation. Change of chlorophyll-a concentration may also affect the capture productions of Atlantic Halibut, Atlantic Salmon and Atlantic Bluefin Tuna. In addition, the variation of ocean salinity and temperature may cause Atlantic Cod and Atlantic Salmon shift their living depths to a deeper level, respectively.