Fish passes

Abstract

A fish pass comprises material ( 1 ) that augments a significant part of the crest of a water penning control structure ( 11 ) and a channel component ( 3 ) to convey water downstream of the water penning control structure ( 11 ), the channel component ( 3 ) having a hinged attachment to the crest of the water penning control structure ( 11 ).

1 . A fish pass which comprises material that augments a significant part of the crest of a water penning control structure and a channel component to convey water downstream of the water penning control structure, the channel component having a hinged attachment to the crest of the water penning control structure. 
   
   
       2 . A fish pass as claimed in  claim 1 , in which a buoyancy unit is attached to the channel component. 
   
   
       3 . A fish pass as claimed in  claim 2 , in which the buoyancy unit is attached adjustably to the channel component. 
   
   
       4 . A fish pass as claimed in  claim 1 , in which the channel component is lined with a bristle substrate. 
   
   
       5 . A fish pass as claimed in  claim 4 , in which the bristle substrate is not parallel to the base of the channel component. 
   
   
       6 . A fish pass as claimed in  claim 5 , which includes triangular end stops that partially blank off the upstream end of the channel component. 
   
   
       7 . A fish pass as claimed in  claim 1 , which includes an upstream element that is movable pivotally relative to the channel component. 
   
   
       8 . A fish pass as claimed in  claim 7 , which includes a gearbox unit for effecting controlled movement of the upstream element relative to the channel component. 
   
   
       9 . A fish pass as claimed in  claim 7 , in which the upstream element is of channel formation and contains a bristle substrate. 
   
   
       10 . A fish pass as claimed in  claim 1 , which includes a cover removably fitted to the channel component.