Xref: utzoo alt.great-lakes:841 sci.bio:5054 Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!zaphod.mps.ohio-state.edu!cis.ohio-state.edu!pacific.mps.ohio-state.edu!linac!midway!clout!chinet!prb From: prb@chinet.chi.il.us (Paul Botts) Newsgroups: alt.great-lakes,sci.bio Subject: Re: zebra mussels spotted in Escanaba, MI Message-ID: <1991May28.194455.17810@chinet.chi.il.us> Date: 28 May 91 19:44:55 GMT References: Organization: Chinet - Chicago Public Access UNIX Lines: 26 In article scs@iti.org (Steve Simmons) writes: >emv@msen.com (Ed Vielmetti) writes: > >>Some questions: > >>- these things are supposed to be widespread in Europe. How do they >> cope with them there? > >They have natural predators in Europe which have not (yet) hitchhiked >over here. >-- Well, no, not really. According to some researchers I talked to for a magazine article, natural predation in Europe (by migratory ducks, mostly) doesn't really keep the mussel population down, just depresses it temporarily in the spring and fall. The real answer is that Europe's industrial infrastructure in much older than in the U.S., and so the intake pipes and so forth in the rivers and lakes have been built bigger for centuries. The zebra mussel spread throughout western Europe from the Caspian Sea area with the construction of a lot of canals on the continent in the first half of the 19th century and the latter half of the 18th. That is before any decent records on biological diversity existed, so tofrom the start of the industrial revolution the little beasties have been considered simply a part of the natural environment, and we have no good picture of what the zebras displaced from the ecosystem.