Estimation of Abundance of Carangids Near the Water Intake of Nuclear Power Plant I by Dual-Beam Hydroacoustic Methods

Abstract

本實驗研究氮鹽及鹽度對金門產壇紫菜測離絲狀體生長之影響。在溫度20℃，光照12小時，和光線强度60μE/m^(2)／s之環境下，把絲狀體培養於三種氮鹽(NO2(上标 -)，NO3(上标 -)，NH4(上标 +))及五種濃度(0.4 mM，1 mM，2 mM，4 mM，10 mM)之變更SWM Ⅲ培養液30天後，測定其乾重量及體積，發現以1 mM NO3(上标 -)之生產量最高，其最後乾重量比原先乾重量增加20.12倍，最後體積比原先體積增加33.25倍。三種氮鹽中，以NO3(上标 -)之生長最好，NO2(上标 -)，NH4(上标 +)者依次遞減。又隨著濃度之增高，生長量有遞減現象，以10 mM NH4(上标 +)者最低，其最後乾重量只比原先乾重量增加6.85倍，最後體積比原先體積增加2.88倍。在培養二個禮拜後，10 mM NO2(上标 -)與10 mM NH4(上标 +)者顏色變淡，生長很差。培養於不同鹽度之變更SWM Ⅲ培養液與前者相同之溫度，光照，時間和光線强度的結果以培養於鹽度30‰者最佳，其最後乾重量比原先乾重量增加4.93倍，最後體積比原先體積增加17.65倍。以50‰生長最差，最後乾重量增加1.14倍，最後體積比原先體積增加8.40倍。鹽度對生長之影響相差不大，但是鹽度由20‰至30‰，其生長量遞增，30‰至50‰則有遞減現象。The influence of NO3(superscript -),NO2(superscript -) and NH4(superscript +)(0.4 mM,1 mM,2 mM,4 mM and10mM)on the growth of the conchocelis of Porphyra haitanensis collectedfrom Kinmen was examined.After 30 days of cultivation in the modifiedSWM Ⅲ solution containing different concentrations of NO3(superscript -),NO2(superscript -)and NH4(superscript +)under the condition of 20℃,12:12 and 60 μE/m^(2)/s,the conchocelis showed anoptimum growth in the medium containing 1 mM NO3(superscript -).Under that conditionit increased 20.12 fold and 33.25 fold in term of dry weight and original volumerespectively.In general,NO3(superscript -)was the most favorable N-source for the growthof conchocelis and NH4(superscript +)the least.It was also found that the growth ofconchocelis decreased with increasing concentration of the N-salts.Theinfluence of different salinities(20,25,30,40,45 and 50‰)on the growth ofthe conchocelis was also tested.Under 20℃,60 μE/m^(2)/s,12:12 condition,theconchocelis grew well in the modified SWM Ⅲ medium at all salinities tested,with optimum at salinity 30‰,at which it increased 4.93 fold in term of dryweight,or 17.65 fold in term of volume.The lowest growth rate was observedin the medium with salinity of 50‰,at which it increased only 1.14 fold and8.40 fold in term of original dry weight and volume respectively.