臺灣蘭嶼海洋重金屬污染之珊瑚紀錄

Abstract

環境污染始終是工業發展下不容忽視的全球議題，各類經由人為活動進入全球生地化循環的污染物質正在改變自然界的平衡狀態，讓環境走向充滿挑戰與未知的未來。近年來環境保護的聲浪愈發強烈，海洋作為全球污染物質的最終匯聚地，自然也受到廣泛的討論與關注，海洋保護與污染監測的行動也應運而生。然而，由於缺乏長期的污染變化紀錄，使得海洋環境污染難以得到有效的評估，同時也大大增加污染防治規劃的困難度，而應用珊瑚地球化學代用指標則成為重建過去海洋環境的重要關鍵。

亞太地區的人為活動自 1970年代開始飛速成長，帶動工業與經濟的蓬勃發展 於此同時也伴隨大量的污染物質暴露到環境當中影響自然生態系統。而台灣位於 亞太地區的樞紐中心也是大氣與海洋環流的交會帶，承上啟下的地理位置，是評 估污染變化以及環境變遷研究的關鍵區域。本研究 以 臺灣蘭嶼地區的 微孔 珊瑚之 碳酸鈣骨骼作為材料，應用地球化學技術重建過去五十年 來 臺灣東南方海域重金 屬鉛、釩、銅濃度之季節性變化並以氣團逆軌跡模型結合鉛同位素分析進行 鉛 污 染溯源與傳輸路徑評估，建構臺灣海洋污染的完整樣貌。研究結果顯示鉛的污染 自 1975年開始上升而在 2010年後逐漸下降，主要受控於區域性地方建設的原地 污染以及季風主導的長距離污染傳輸，形成季節性的污染源遷移現象，與亞太地 區含鉛汽油與煤炭燃燒的使用歷史高度相關，同時也佐證中國作為主要污染源對 西太平洋的 長期 污染貢獻；釩污染則是紀錄到臺灣東部外海的漏油事件以及二戰 的軍事活動，而長期趨勢於 2005年後受到蘭嶼觀光發展所帶來的船運以及人為垃 圾污水的影響而有所上升；銅污染變化則是除了二戰時期的軍事活動之外，皆處 於穩定的自然波動狀態，意味著沒有顯著的銅污染存在。研究的結果也顯示三種 重金屬元素分別受控於不同的污染因子，指示著臺 灣海洋環境受到多元污染源的 影響。本研究得易於地理位置、高解析度採樣以及超微量金屬分析技術，首次建 立臺灣海洋環境長期的重金屬季節性變化歷史，得以評估自然擾動與人類活動的 交互關係，以及西北太平洋的污染控制因子，提供全面性的污染重建紀錄。

Environmental pollution remains a critical global issue amid ongoing industrial development. Anthropogenic activities have introduced a range of pollutants into global biogeochemical cycles, disrupting natural balances and driving environmental systems toward increasing uncertainty. In recent years, heightened awareness and advocacy for environmental protection have emphasized the need for marine pollution monitoring, as the ocean acts as a major sink for many pollutants. However, the absence of long-term pollution records has limited our ability to assess marine environmental degradation and hindered the development of effective mitigation strategies. In this context, coral-based geochemical proxies have emerged as a powerful tool for reconstructing historical oceanic conditions.

Since the 1970s, rapid industrialization and economic expansion across the Asia-Pacific region have significantly increased pollutant emissions. Taiwan, located at the intersection of major atmospheric and oceanic circulation systems, provides a strategic setting for investigating pollution dynamics. Here we reconstruct seasonal variations in lead (Pb), vanadium (V), and copper (Cu) concentrations over the past 50 years using massive Porites corals collected from Lanyu, southeastern Taiwan. By integrating Pb isotopic analysis with back-trajectory modeling, we trace pollution sources and transport pathways to build a comprehensive picture of marine pollution in the region. Our results show a rise in Pb pollution beginning around 1975, followed by a decline after 2010, largely driven by local emissions and long-range transport modulated by monsoonal winds. These patterns align with the regional history of leaded gasoline use and coal combustion, underscoring China's major role in western Pacific pollution. V records reflect localized events such as oil spills and wartime military activities, with a post-2005 increase likely linked to tourism-driven maritime traffic and waste discharge. In contrast, Cu concentrations remained within natural variability, suggesting minimal anthropogenic influence. This study presents the first long-term, seasonally resolved record of heavy metal variability in Taiwan’s marine environment. It highlights the distinct sources and transport mechanisms influencing different pollutants and provides crucial insights into the interaction between human activities and natural processes in the northwestern Pacific.