@article{oai:nodai.repo.nii.ac.jp:00000900, author = {松田, 烈至 and 園田, 武 and Matsuda, Retsush and Sonoda, Takesh}, issue = {3}, month = {Dec}, note = {北海道オホーツク海側沿岸海跡湖の流域では農畜産業が広く営まれており,それらの活動に由来する様々な物質は流域の末端である汽水域に一時的に蓄積される。それらの物質の中で肥料由来重金属である銅,マンガン,亜鉛は水生生物に対する毒性が高いと考えられるが,日本の汽水域を代表する水産有用種のヤマトシジミの重金属耐性についてはほとんどわかっていない。そこで本研究はヤマトシジミの銅,マンガン,亜鉛に対する耐性実験を行い,生残への影響について明らかにすることを目的として行った。その結果,本研究で得られた半数致死濃度(以下LC50)は銅が27.3(3.8-50.7:90%信頼区間) mg/L,マンガンが292.0(184.4-399.7:95%信頼区間) mg/Lだった。亜鉛は0~100 mg/Lに72時間曝露した後の生残率は91.6%だった。これらの値は他の水生生物の生残率の減少を引き起こす濃度やLC50よりも高く,ヤマトシジミは高い重金属耐性を有していることが明らかとなった。しかしながら,北海道オホーツク海側沿岸海跡湖の流域では,融雪出水や降雨に伴う農地崩落がしばしば起こっている。そうした農地の土壌中にはヤマトシジミのLC50と同程度の濃度の重金属が蓄積されている可能性もあり,北海道オホーツク海側沿岸海跡湖のヤマトシジミ漁場では農地由来重金属の潜在的なリスクが懸念される。, Agriculture and livestock industry is widely practiced in the river basin of the sea of Okhotsk side of Hokkaido. Various substances derived from such agricultural activities have been temporarily accumulated in the brackish water area at the end of the river basin. Heavy metals from manure compost, such as copper, manganese and zinc, are considered to be highly toxic to aquatic organisms. Little is known about the heavy metal tolerance of Corbicula japonica, which is an important fishery resource of brackish waters in Japan. The purpose of this study is to clarify tolerance of this clam against copper, manganese and zinc. LC50 of copper and manganese was 27.3 mg/L and 292.0 mg/L, respectively. The survival rate after exposing the clam to a 100 mg/L of zinc solution for 72 hours was 91.6%. These values are higher than LC50 and decrease of survival rate on other aquatic organisms. From the results, it was clarified that C. japonica has high tolerance to these heavy metals. However, agricultural land slides often occur in the basin of Okhotsk area of Hokkaido, due to snowmelt floods and heavy rainfalls. There is concern about the potential risk of farmland-derived heavy metals, as heavy metals with similar concentration to LC50 of C. japonica may have accumulated in the soil of such farmlands., E, 2, P, 論文, Article}, pages = {58--64}, title = {汽水性二枚貝ヤマトシジミの重金属耐性}, volume = {66}, year = {2021}, yomi = {マツダ, レツシ and ソノダ, タケシ} }