MONITORING TECHNIQUES FOR FISHWAYS

Abstract

1. MONITORING FISHWAYS Monitoring the performance of fishways and any functional controls associated with them are important operations for several reasons:-To verify the efficiency of fishways after they have been commissioned and to adjust their operation if necessary.-To gather technical and biological information which will be indispensable for the design and development of future fishways (operational feedback).-To quantify migratory fish populations and describe the pattern of their migration, which is necessary both for the design of any fishways to be constructed upstream on the same watercourse and for rational stock management. The techniques employed can be summarised under several headings:-Monitoring the hydraulic and mechanical operation of the fishway.-Collecting qualitative biological information indicating the effectiveness of fish passage.-Counting fish using the fishway.-Comparing the number of fish using the fishway to the migrating population as a whole, thus expressing the true efficiency of the fishway. 2. MONITORING HYDRAULIC AND MECHANICAL OPERATION A number of simple measurements and observations should be made both at the time of commissioning and at regular intervals afterwards, to ensure that the fishway conforms to the criteria specified when it was designed.