Redefining Fish Passage Parameters

April 2, 2026

Hi everyone,

It’s been a while since we last shared any fish passage updates – and this one is worth the wait. With a long weekend ahead, you’ll have plenty of time to dig in!

The reality is that many of our current regulations and the information underpinning them have significant gaps and are overdue for reform.

The Fish Passage Action Team has put together the key principles behind assessing fish passage and designing effective fishways at stream-infrastructure crossings. Drawing on revisited foundational research, emerging knowledge, and extensive field experience, we’ve produced work we think is genuinely valuable:

  • Presentation on hydraulic complexity & flow characteristics and how this affects fish.
  • Document on reframing fish passage – from single metric & meaningless averages to structured complexity.

­ Click to view presentation ­ If fish passage matters to you and you care about getting it right, please read the document and review the PowerPoint. Then pass it along – to regulators, engineers, ecologists, and practitioners alike – so we can move beyond outdated designs and methodologies once and for all.
­ Click to view key principles document ­

Recent Blog Updates

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Fish Passage Remediation Example

Hi everyone, Check out the video below showing a great example of fish passage remediation targeting small-bodied NZ fish species. The fixes address: The perched apronThe perched culvert outletShallowing of the apronFast laminar flow within the culvert Note: This...

If you are serious about restoring fish passage, watch and share this fun video essay.

This video essay created by the Fish Passage Action Team outlines the easy to follow process for undertaking multi-site fish passage remediation programs.  The key is to make the most of data collected to plan actual work programs, and not just produce dots on a map...

Region Wide Fish Passage Program

Hi everyone  Check out this video released by the Ministry for the Environment (NZ) showing the great work Kūmānu Environmental and Tasman District Council have been doing to restore fish passage in the Tasman Region. This 5 year project will allow 7,000+ desktop...

Pacific Lamprey Video

Hi everyone,  One of our Fish Passage Action Team members, Kelly, captured this unusual footage whilst recently travelling in the USA to attend the International Fish Passage conference.  Pacific Lamprey are often overlooked when it comes to fish passage....

Fish Passage from North to South NZ

Hi everyone It's always great to see a growing number of people getting stuck into fish passage throughout New Zealand. Aided by the newly released Fish Passage Remediation Training Aid 2022, teams of practitioners are better equipped than ever before to restore...

New and improved protocol for monitoring fish passage

Hi all, Tasman District Council in NZ has recently undertaken an unprecedented 23 day fish passage trial assessing fish movement through a twin barrel culvert. The trial involved capturing and counting fish daily as they naturally migrated upstream through the culvert...

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