North Temperate Lakes LTER: Snail Survey in Northern Wisconsin Lakes 2006

The Chinese mystery snail (Bellamya chinensis) is a large invasive gastropod that achieves high densities in waters across North America, yet little is known about its ecological significance in invaded systems. We surveyed 44 lakes to describe the patterns and determinants of B. chinensis distributions in northern Wisconsin, U.S.A., and to assess the likelihood of effects on native snail communities in the invaded systems. B. chinensis was widespread among surveyed lakes (21 of 42 lakes with snails) and its occurrence was correlated with indicators of lake productivity and anthropogenic dispersal vectors (boat landings, distance to population centers, shoreline housing density). Some native snail species tended not to occur at sites where B. chinensis was abundant; among these was Lymnaea stagnalis, which suffered reduced survival in the presence of B. chinensis in a recently published mesocosm study. However, there was no difference in overall snail assemblage structure at either the site or lake level as a function of B. chinensis presence or abundance. Lake occurrences of many snail species have apparently been lost over time, but a comparison to a 1930's survey showed that there was no increased likelihood of species loss in lakes invaded by B. chinensis (or by the invasive crayfish Orconectes rusticus). Although B. chinensis is widespread and sometimes abundant in northern Wisconsin lakes, it does not appear to have strong systematic impacts on native snail assemblages. Solomon, C.T., J.D.Olden, P.T. J. Johnson, R.T. Dillon Jr., and M. Jake Vander Zanden. 2010. Distribution and community-level effects of the Chinese mystery snail (Bellamya chinensis) in northern Wisconsin lakes. Biological Invasions 12:1591–1605. Number of sites: Sites surveyed within 44 lakes. Sampling Frequency: Each lake surveyed once in summer of 2006

中华田螺（Bellamya chinensis）是一种大型入侵腹足类软体动物（gastropod），在美国北部水域中可形成极高种群密度，但其在入侵生态系统中的生态学意义却鲜有相关研究。我们对44座湖泊开展了调查，旨在阐明美国威斯康星州北部中华田螺分布的格局及其影响因子，并评估其对入侵系统中原生螺类群落的潜在影响。中华田螺在所调查的湖泊中分布广泛（42个检出螺类的湖泊中共有21个存在该物种），其出现与否与湖泊生产力指标及人为传播媒介（船只停靠点、距人口聚居区的距离、岸线住宅密度）显著相关。部分原生螺类物种在中华田螺种群密集的位点出现概率较低，其中包括静水椎实螺（Lymnaea stagnalis）——近期一项中型实验生态系统（mesocosm）研究显示，该物种在中华田螺存在时存活率显著下降。然而，无论在点位还是湖泊尺度上，螺类群落的整体结构均未因中华田螺的存在或种群密度而出现显著差异。随着时间推移，诸多螺类物种的湖泊分布记录似乎已出现缺失，但与1930年代的调查数据对比后发现，被中华田螺（或入侵螯虾锈螯虾Orconectes rusticus）入侵的湖泊中，物种丢失的概率并未升高。尽管中华田螺在威斯康星州北部湖泊中分布广泛且局部种群密度较高，但其并未对原生螺类群落产生显著的系统性影响。本研究数据源自Solomon CT、Olden JD、Johnson PTJ、Dillon RT Jr.及Vander Zanden MJ于2010年发表在《生物入侵（Biological Invasions）》第12卷1591–1605页的论文《威斯康星州北部湖泊中华田螺的分布及其对群落的影响》（原标题：Distribution and community-level effects of the Chinese mystery snail (Bellamya chinensis) in northern Wisconsin lakes）。调查点位：44座湖泊内布设的采样位点。采样频次：2006年夏季对每座湖泊仅开展1次采样。