INZ, in conjunction with Fish & Game, Department of Conservation and Environment Canterbury, have been coordinating research into the effectiveness and applicability of fish screening methods used in New Zealand. Screens of various construction techniques have been tested using live fish. The initial project aimed to update the NIWA “Good Practice guidelines.” However, the specific testing was unable to definitively test each criteria, so the end result is a findings report to be read in conjunction with the NIWA guidelines. Each individual screen test and the findings report are available.
Results to date reveal the two main factors for effective fish exclusion are:
- the design and provision of the by-pass components
- regular maintenance of the fish screen
The findings report goes into more detail on these and other points. Further trials are planned to test the importance and impact of different mesh size.