中文摘要 |
本研究分析海上觀察員自2005至2006年,在大西洋、印度洋及大西洋所採集的劍旗魚肌肉,測定其中的總汞(THg)及有機汞(OHg)濃度(mg/ kg鮮重),用以探討其是否有洋區、體型及性別上的差異。結果顯示三大洋區的劍旗魚肌肉總汞及有機汞濃度有顯著的洋區差異,以大西洋(THg = 1.64 ± 0.91, n = 92;OHg = 1.31 ± 0.73, n = 17)及印度洋(THg = 1.28 ± 0.75, n = 32;OHg = 1.10 ± 0.62, n = 22)明顯高於太平洋(THg = 0.88 ± 0.49, n = 76;OHg = 0.68 ± 0.52, n = 21)。三大洋的劍旗魚肌肉總汞濃度皆隨體型增加而升高,但有機汞濃度與體型的正相關係,僅在印度洋及大西洋有顯著,而太平洋則無。比較同體型劍旗魚肌肉中之總汞濃度,本研究與其他研究相比並無顯著差異存在。印度洋、大西洋及太平洋劍旗魚肌肉中的總汞及有機汞濃度皆無明顯的性別差異。整體而言,劍旗魚肌肉中的有機汞濃度約佔總汞濃度的80%。 |
英文摘要 |
During 2005 to 2006, muscle samples of swordfish (Xiphias gladius) were collected by fisheries inspectors on board of Taiwanese longline vessels operated in the Atlantic, Indian and Pacific Oceans. Total mercury (THg) and organic mercury (OHg) concentrations (mg/kg flesh weight) of the samples were determined. The results showed that the THg and OHg levels were higher in Atlantic (THg=1.64±0.91, n=92;OHg=1.31±0.73, n=17) and Indian (THg=1.28±0.75, n=32;OHg=1.10±0.62, n=22) than those in Pacific (THg=0.88±0.49, n=76;OHg=0.68±0.52, n=21). Linear regressions between THg and fork length (FL) of swordfish was found in the three oceans, however, such regression between OHg and FL was only showed in Atlantic and Indian Oceans, but not in Pacific Ocean. The adjusted values of THg to the same size of the fish were similar to various previous studies. No significant sex differences of the Hg concentrations were observed. Meanwhile, the percentage of OHg over THg was about 80% in the muscles of swordfish. |