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The ICE protocol for ecological continuity ; Assessing the passage of obstacles by fish

Concepts design and application

Biological communities are in constant interaction both among themselves and with their environment. They support an array of ecological processes that enable ecosystems to function, to regenerate, to evolve, thus providing humanity with the ecosystem services required for its survival. Since the industrial and agricultural revolutions, humans have considerably increased their impact on biodiversity by vastly augmenting the number and the intensity of the pressures that they bring to bear on natural environments. The contemporary period since 1900 has thus seen one of the greatest extinction events that the planet has ever known. Chemical pollution has long been identified as a source of pressures and numerous measures have been taken to reduce chemical emissions, however awareness concerning the effects of physical alterations in environments is more recent. Those alterations are nonetheless of major importance and habitat fragmentation of living communities is now seen as one of the main causes of biodiversity loss. This new awareness is the result of better understanding of the essential role played by the connectivity of natural areas in the biological cycles of living species and of the functions provided by those cycles for the genetic mixing required to ensure the survival of populations and the evolution of species, as well as for numerous geophysical and geochemical processes within ecosystems.

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  Front cover
  Foreword, preface, note

Ecological continuity and fish

The issues involved in the movement of fish
The capabilities of fish to overcome obstacles


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General principles underlying the ICE protocol

Protocol modus operandi
Definition of species groups
Definition of passability classes


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Assessment of passability during upstream migration

Fixed elements of weirs and dams
Moving parts of an obstacle
Road/rail structures
Tidal structures
Complex and mixed structures
Eels, a special case


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Pre-assessment of obstacles equiped with a fish pass

The different types of fish pass
Pre-assessment of the different types of fish pass


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  Bibliography, main symbols and abbreviations
  Acknowledgements and covers



















  Jean-Marc Baudoin,