利用石墨式原子吸收光譜儀分析鱗片錳元素濃度以判別放流與野生黑鯛

Discrimination of wild and hatchery-reared black porgy (Acanthopagrus schlegeli) based on manganese of scales by graphite furnace atomic absorption spectrometer

張承容(Cheng-Jung Chang)

指導教授 ： 李英周

共同指導教授 ： 林曉武

國立臺灣大學/生命科學院/漁業科學研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.01051

摘要

台灣的魚苗放流工作已經進行了許多年，每年放流魚苗種類有黑鯛、嘉鱲、金目鱸、白星笛鯛…多達十餘種種類，除了少數物種如九孔、黑鯛曾進行研究外，其餘放流魚種皆未有足夠的相關研究報告來說明放流工作之成效。而欲評估魚苗放流效果，判別野生與放流再捕魚是很重要的工作。目前評估放流效益的方式，主要是以標識放流再進行放流魚回收為主，但此方法無法分辨未進行標識放流及更早之前就曾經放流的魚群。另有利用耳石化學元素中鎂與錳差異作為判別放流與野生黑鯛之依據，但此分析方法價格過於昂貴，因此找出省時、成本低的判別方法是非常重要的研究課題。本研究觀察5尾養殖及5尾標識再捕黑鯛的鱗片，並利用石墨式原子吸收光譜儀分析鱗片核心及邊緣部份的錳元素，依述分析結果，作為建立海中捕獲黑鯛來源的判別依據。
本研究共分析20尾海中捕獲且體表無標識之未知魚，結果顯示4尾未知魚可在鱗相上觀察到不連續帶記號，10尾未知魚鱗片結果顯示核心錳元素濃度皆高於邊緣部份，故推測20尾未知魚中，10尾可能為放流再捕魚，10尾可能為野生魚。建議未來判斷未知魚來源時，先初步觀察未知魚鱗相，再分析鱗片錳元素濃度，最後有疑問之樣本才需進行耳石鎂、錳元素分析，如此可有效減少花費的時間與經費，也可計算出早年未經標識放流的放流魚對海中資源的貢獻度，未來更容易進行資源的管理與研擬更好的放流方式。

關鍵字

黑鯛 ； 鱗片 ； 標識放流 ； 石墨式原子吸收光譜儀

並列摘要

The restocking programs were conducted for many years in Taiwan. There are more than ten species released to the surrounding waters of Taiwan every year, i.e., black sea bream (Acanthopagrus schlegeli), Japanese sea bream (Pagrus major) and giant sea perch (Lates japonicas) etc. However, in the past, the effectiveness of the restocking program was not often evaluated except black sea bream and abalone. It is important to discriminate wild and hatchery-reared individual for the assessment of restocking program. In present, the major method to assess the effect of fry releasing was marked and recaptured. But this method could not identify the released individuals that were not marked before marked and released experiments. And there was another method using otolith elements analysis of magnesium (Mg) and manganese (Mn) to distinguish wild and hatchery-reared black porgy. However, this method was time consuming and too expensive. Therefore, it is important to find the discrimination methods requiring short operations time and inexpensive. This study examined the scale characteristics of five hatchery-reared and five recaptured marked-fish, and their manganese (Mn) of scales was investigated by graphite furnace atomic absorption spectroscope (GFAAS). According to the results, the discrimination criteria of captured black porgy were established.
There were twenty captured individuals were analyzed in this study. Four unknown fish showed the stocking check, and ten showed that the Mn of scales was higher in the core area than in the periphery area among all fish. Thereby, this study suggested ten individuals may be hatchery-reared fish and ten individual may be wild fish. This study suggests when discriminate original unknown fish, first, observed fish scale then analyzed Mn in scale. Finally, when there are still some doubt samples, Mg and Mn analysis will be necessary. By this way, time and expenditure can be reduced and the contribution of the previously unmark releasing fish be estimated. It will do merits to future resource administration and releasing projects.

並列關鍵字

black porgy, Acanthopagrus schlegeli ； scales ； marked and release ； GFAAS

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