Fish Passage Failure & Fix Video

August 20, 2026

Hi everyone,

Tim Olley has shared a short video that clearly captures weak-swimming inanga/common galaxias (Galaxias maculatus) struggling – and ultimately failing – to pass through a culvert with fast, laminar-type flow.

The second half of the video shows the same culvert post-baffle installation: velocities are reduced and rest pools are created, giving the fish the breaks they need to make it through.

This footage was captured as part of a research project investigating the swimming ability of small-bodied fish.

Enjoy!

Recent Posts

Advanced AI fish recognition and tracking

The Fish Passage Action Team is working to develop a portable field camera for identifying and tracking fish.

Exploring Velocities Below the Surface

The next generation of CFD modelling allows us to see below the surface in complex flows to identify swim paths.

123 Sea Trout, One Culvert, One Year

Sweco Norway are putting FlexiBaffles to work in Bergen and the results speak for themselves

Redefining Fish Passage Parameters

Two worthwhile documents shedding new light on fish passage

Great news! Tide/Flood Gates need no longer be a fish barrier – there is a solution

Queensland case study low-cost option for improving fish passage and water quality upstream of tide/flood gates

Awesome Free Culvert Baffle Design Calculator

New from FPAT: a free calculator for culvert baffle design with downloadable drawings.

From training to action: Gisborne gets started

Council and local iwi join forces to map fish barriers in Gisborne, New Zealand

First coho salmon for 70 years!

Surrey City, BC, Canada is celebrating the return of coho salmon for the first time in 70 years.

Studies Show Innovative Ramps Improve Fish Passage

Hello everyone, Tasman District Council (NZ) continues to be a world leader in region-wide fish passage remediation programmes. Tasman has remediated thousands of fish barriers using a range of cost-effective methods. Two of the most commonly used are flexible rubber...

Fresh Brand, Enhanced Resources – The New FPAT

Hi there, Big news – we've rebranded and completely upgraded our website! The Fish Passage Action Team remains a collaborative, non-profit platform where everyone can contribute, now with enhanced features and easier access to resources for fish passage and barrier...

← Exploring Velocities Below the Surface Advanced AI fish recognition and tracking →