Studiies on the biodiversity in sand dun lakes distributedin Niigaat and Aomori Prefecture

以沙丘周围泉水为水源的沙丘湖在日本主要分布在新泻和青森地区。由于其大量的大型植物，被认为具有很高的生物多样性。但是，最近它们被坚硬的湖岸破坏了，比如混凝土和建筑用的大块沙子取样。新泻和青森地区对沙丘湖的生物多样性和湖泊富营养化进行了迫切的研究。对65个沙丘湖进行了湖沼学描述和动植物区系研究（新潟：26，青森39）。新潟和库比山沙丘湖群共记录了5门173个底栖无脊椎动物，滨釜山沙丘湖群共记录了8门196个类群，下摩基塔沙丘湖群共记录了5门135个类群。报道了新泻地区棘球蚴（Cercion plagiosum）等10种濒危无脊椎动物和釜山地区Culumenella prashadi等12种濒危无脊椎动物的分布情况。此外，还发现了许多水生植物，如新泻地区的含盐植物乌氏ferox等43种，滨釜山地区的Caldesia parnasifflria等10种，下喜多地区的Najas yezoensis等12种。结果表明，对日本沙丘湖生物多样性的保护迫在眉睫。

Distribution of sand dune lakes which were fed from the spring water around sand dunes in Japan is restricted to Niigata and Aomori Prefecture. Its have been estimated to be high biodiversity because of mass amount of macrophytes. But, recently they have damaged by hard lakeshore, such as concrete and sampling of mass sand for architectural use. Urgent studies for sand dune lakes, particularly focused to biodiversity and eutrophication of lakes were conducted in Niigata and Aomori. Limnological description and researches on fauna and flora were conducted in sixty-five sand dune lakes (Niigata: 26, Aomori 39). Many species of benthic invertebrates, 173 taxa belonging to 5 phyla from Niigata and Kubikisand dune lake group, 196 taxa belonging to 8 phyla from Byoubusan sand dune lake group, 135 taxa belonging to 5 phyla from Shimokita sand dune lake group were recorded during study. Distribution of ten endangered species of invertebrates such as Cercion plagiosum from Niigata, 12 species such as Culumenella prashadi from Byoubusan were reported. Many species of aquatic macrophytes, 43 species such as Eulyale ferox including halophytes from Niigata, 10 species such as Caldesia parnasifflria from Byoubusan and 12 species such as Najas yezoensis from Shimokita were also reported. Our results show the protection of biodiversity in sand dune lakes in Japan is urgently needed.