| 中文摘要 |
魚苗放流是栽培漁業中重要的一環，主要目的是強化野外的漁業資源，而標識魚類後放流再捕通常是研究魚群大小、分布、移動以及評估魚苗放流成效的方法之一。標誌的方法有許多種，包括切鰭法、烙印法和刺青法等等，但這些方法對於數量龐大的放流魚苗來說，大多為昂貴且費時的，因此找出省時、成本低且檢測容易的大量標誌法(mass-marking)是非常重要的研究課題。本研究在桃園縣的民間養殖場中針對體長4.0 cm-8.5 cm的黑鯛(Acanthopagrus schlegeli)魚苗進行大量標誌方法試驗，並採用合適的方法大量標誌魚苗後放流，並利用再捕的數據進行放流效益的評估，結果如下。四環黴素餵食法(餵食魚隻含有四環黴素的飼料)，加上噴槍法(利用高壓噴槍將螢光色素打在魚的表皮)的雙重標誌方法(先投餵四環黴素後再使用噴槍法)是適合黑鯛魚苗的大量標誌法。本研究在2005年7月21日到9月23日期間共標識了約十萬八千尾的黑鯛魚苗後放流至苗栗縣白沙屯一帶海域，到目前2006年10月總檢測漁獲548尾，其中有標誌魚41尾，該沿岸海域1月到10月的黑鯛的時間別CPUE (ind./fishing hr.)分別為1.50、2.25、4.25、4.85、6.66、9.75、0.75、3.27、3.00、0.60，利用Petersen法估計資源量為1,411,727尾，95% CI = 997,952-1,825,502尾，另以Schnabel法的初估值為1,446,040尾，95% CI = 1,437,578-1,454,502尾，放流貢獻度為8.7%。本研究發現雙重標識法是一個大量魚苗標誌的良好方法，建議將來可以推廣至其他種魚苗進行雙重標識後放流，再配合漁民們的回報數據，來評估放流的成效以及野外資源量，以期建立栽培漁業。 |
| 英文摘要 |
The fry hatchery-reared and released was an important part of sea-ranching in order to enhance the natural fisheries stocks. The marked fish released and captured were used to study the population size, distribution, movement, and assessment of wild population. Most marking methods, for instance fin-clipped, branding and tattoo, etc. were expensive and time-consumed for mass marking of released fry. Therefore, it is important to find the methods of mass-marking with time-saving, low cost and detected easily. The juveniles of black porgy（Acanthopagrus schlegeli）with 4.0cm-8.5cm using the methods of mass-marking were carried out in a hatchery in Taoyuan county, and then released to the sea water. The results were as follows.
We found that the double marking method, i.e., the fish sprayed with fluorescent pigment spraying on the skin of fish after fed with tetracycline was a suitable and good marking method for juveniles of black porgy. About one hundred and eight thousands juveniles of black porgy were marked and released to sea water in Baishatun, Moiland county during July 21- September 23. Total 41 marked fishes had been recaptured up to present October, 2006. The CPUE（ind./fishing hr.）from January to October were 1.50, 2.25, 4.25, 4.85, 6.66, 9.75, 0.75, 3.27, 3.00, 0.60, respectively. The stock size in the water was estimated as 1,411,727 (95% CI = 997,952-1,825,502) and 1,446,040 (95% CI = 1,437,578-1,454,502) by Petersen and Schnabel methods, respectively. The stock contribution of released black porgy was 8.7%. It was suggested that fed with tetracycline and spraying fluorescent pigment can be adopted as a good double marking method on fish juveniles. In the future, combining the double marking method and the recovered data from fishermen to evaluate the releasing effects and population stock size in sea water will benefit the sea-ranching. |