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Title: 2・3の海産浮游幼生に及ぼす高温と残溜塩素の影響について
Other Titles: Influences of High Temperature and Residual Chlorine on the Marine Planktonic Larvae
Authors: 平山, 和次 / 平野, 礼次郎
Authors (alternative): Hirayama, Kazutsugu / Hirano, Reijiro
Issue Date: Aug-1970
Publisher: 長崎大学水産学部
Citation: 長崎大学水産学部研究報告, v.29, pp.83-89; 1970
Abstract: Increased utilization of sea water for cooling purpose in electricity generating industry and in other industrial processes has made it necessary to consider the biological influences of its effluents on marine life in the adjacent area. Hence, as the direct influences of the effluents, the lethal points of high temperature and residual chlorine for marine planktonic larvae in various exposure periods were studied. The experiments against high temperature were performed with the purple sea urckin (Anthocidaries crassipina) larvae in early stage (2-4 cells), blastula stage and pluteus stage, with the rock barnacle (Balanus amphitrite albicostatus) larvae in nauplius stage, and with the oyster (Crassostrea gigas) larvae in blastula stage. The lethal influences of residual chlorine on the blue mussele (mytilus edulis) in early stage (2-4 cells) and trochophore stage were studied in detail in relation to the exposure periods. Results obtained are as follows. 1) As shown in Table 3, early stage larvae of the purple sea urckin have the least tolerance to high temperature among the examined larval animals. They cannot survive the treatment at the temperature of 33℃ for 20 minutes. Nauplius II larvae of the rock barnacle have the most tolerance to high temperature being able to tolerate 40 minutes' treatment at 40℃. 2) TLm (median tolerance limit) of chlorine for the blue mussele larvae for 5 and 10 minutes exposure periods are shown in Fig. 1. The 10 min-TLm values for early stage larvae (2-4 cells) and for trochophore stage larvae and the 5 min-TLm value for early stage larvae are shown as 1.15, 1.31 and 1.21 ppm., respectively. The differences among these values are minimal. However, the 5 min-TLm value for trochophore stage larvae, 2.37 ppm. is considerably high as compared with the other TLm values, Accordingly, it is clear that within 5 min exposure period, the blue mussele larvae in late stage become more tolerate to chlorine along with the larval development. These results suggest that within the extent of this experimental studty, heated effluents in electricity generating industry facing the open sea may not bring at least the direct influences on marine planktonic larvae in the vicinity on account of their rapid diffusion. / ムラサキウニ,マガキ,シロスジフジツボ,ムラサキイガイを用い,それらの幼生に及ぼす高温と塩素の影響を検討した. その結果 1) 高温の影響はTable 3に示したように,ムラサキウニの発生初期が最も抵抗性が小さく,約33℃に20分放置すると死滅する.一方,シロスジフジツボのII期ナウプリウスは最も強く,40℃に40分放置しても死滅することはない. 2) ムラサキイガイ幼生に及ぼす遊離塩素の影響は,受精初期の5分間と10分間のTLmおよびトロコホア期の10分間TLmは,それぞれ1.21, 1.15および1.31ppmで,大きな差はないが,発生が進み,トロコホア期になると,短時間の作用ではかなり高濃度にも耐えうるようになり,10分間TLmは2.37ppmになる. 3) 以上の事実から,火力発電所の温排水が付近海域の海産浮游幼生に,少くとも,直接的な影響を及ぼす可能性は少ないと考えられる.
URI: http://hdl.handle.net/10069/31198
ISSN: 05471427
Type: Departmental Bulletin Paper
Text Version: publisher
Appears in Collections:第29号

Citable URI : http://hdl.handle.net/10069/31198

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