報告書番号

V08014

タイトル（和文）

懸濁物質が魚類に及ぼす影響 －粘土鉱物（パイロフィライト、セリサイト）がヒラメの生存に及ぼす影響

タイトル（英文）

Effects of suspended solids on fish - Lethal effects of clay minerals (pyrophyllite and sericite) on Japanese flounder

概要 （図表や脚注は「報告書全文」に掲載しております）

懸濁物質が魚類に及ぼす影響の解明に資するため、粘土鉱物のパイロフィライト、セリサイトがヒラメの生存に及ぼす影響を調べた。
海水直接添加と淡水添加後海水添加の2条件でパイロフィライト、セリサイトを18.8～300g/Lで懸濁させた海水中で96時間、ヒラメ（全長約6cm）を飼育した。パイロフィライトでは96時間半数致死濃度（96ｈLC50）は海水直接添加条件で43g/L、淡水添加後海水添加条件で62g/L、最大無作用濃度（NOEC）はそれぞれ19g/Lと38g/Lであった。また、セリサイトでは96hLC50は海水直接添加条件で75g/L、淡水添加後海水添加条件で192g/L、NOECはそれぞれ38g/L、75g/Lであり、いずれの粘土鉱物も海水直接添加条件に比べて淡水添加後海水添加条件でヒラメの生残への影響が低下した。

概要 （英文）

Effects of clay minerals suspended in seawater on survivability of the Japanese flounder were examined. Fish (6cm in total length) were kept for 96hrs in pyrophyllite or sericite suspended seawater at concentrations of 0, 18.8, 37.5, 75.0, 150, 300 g/L. These clay minerals were added into seawater in two manners; directly as powder, indirectly as concentrated suspension in fresh water. Lethal effects of the minerals on fish were different between the two manners of addition; the minerals added directly were more detrimental than those added indirectly. The 96h LC50 (50% Lethal Concentration) values of pyrophyllite and sericite were 43 g/L and 75 g/L, respectively, when the minerals were added as powder into seawater., and the 96h LC50 values were 62g/L (pyrophyllite) and 192 g/L (sericite) when they added as suspensions in fresh water.

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