Guidelines for monitoring fish passage success

Whether it is a new instream structure being installed, or remediation of an existing structure, planning and implementing an effective monitoring and maintenance programme before the works are undertaken is an essential part of the project. However, relatively few fish passage solutions have had robust and independent monitoring programmes carried out to evaluate their success and ensure an effective use of capital resources. 

This manual describes evidence-based methods suitable for evaluating the effectiveness of fish passage solutions. These methods can be used to ensure that solutions are fit-for-purpose and fulfil objectives for improving upstream fish communities. This provides greater certainty for regional councils, tangata whenua and asset owners that their investments are optimised and are effective.

Fish Passage Monitoring ManualDownload PDF [14.67 MB]

Contents

• Introduction
• Fish passage objectives and performance standards
• Monitoring fish passage success
• Setting objectives
• Survey methods
• Survey protocols
• Fish processing
• Survey timing
• Defining success
• Physical & hydraulic monitoring

Monitoring is the only way to understand how well a structure is working. It is essential for ensuring that any reduction in fish passage caused by a structure is not adversely impacting upstream communities and that environmental outcomes are being achieved. It is particularly important to understand how well a structure is functioning in situations where:  

• High value fish communities or ecosystems are present, or are expected to be present, upstream of the structure.  

• Unproven designs are being used.  

• Proven designs are being used in novel situations.  

• Retrofit solutions form only one component of an instream structure.  

• Multiple structures exist within a waterway causing cumulative effects.  

• Selective barriers are being used to manage the movement of undesirable species.  

The monitoring methods outlined in this manual will ensure that fish passage assessments are fit-for-purpose and consistent across New Zealand, enabling a comparison of efficacy, and consequently ensuring that investment leads to the best possible outcomes for fish passage, catchment connectivity, and threatened species restoration.