“Restoring fish passage and reconnecting waterways – it’s our passion”
Hi all,
Some of the Fish Passage Action Team were recently involved in a very satisfying restoration project.
It is rare that we get the opportunity to completely remove culverts in an effort to restore fish passage so we wanted to share this with you.
See what two workers and a small excavator can manage in a day.
Alex put together this short “Glide-Show” so you can scroll through it at your own pace.
Hi everyone,
During the lockdown, we have revamped one of our favourite videos that has been enjoyed by ecologists, engineers, and many others in helping to understand why migrating fish need complex flows.
The video highlights the importance of complex flows and how baffles can help to achieve this.
We have lots more interesting fish passage videos in the wings, so watch this space!
Stay Safe,
Fish Passage Action Team
Hi everyone
Many of you will be aware that observing, measuring and understanding the complex flows in which fish move is very challenging.
Below are a few interesting images that have been created by the Fish Passage Action Team using CFD modelling.
There are many options for displaying the results, but the fantastic thing is having the ability to see the velocity and direction of the flow down through the water column.
We are currently building a library with models using different flow rates, culvert types, baffle configurations etc.
If you have a particular project that would benefit from this type of simulation, don’t hesitate to get in touch with the team directly.
Note: A table with the model’s parameters is in the top right corner of each image.
Tim Olley has shared this video showing the same juvenile eel climbing up three different surfaces, including mussel-rope.
| Hi everyone Fish need to have access to spawning sites. Here is a link to a really nice video showing stage-one of a manmade spawning and nurturing site for inanga (galaxiid maculatus) though many other species with make this place home. The pools will soon be planted and connected to the main canals leading to the Little Waihi estuary. Twice daily tides will flush the ponds and provide the potential for spawning each autumn. This project is being led and funded by the Bay of Plenty Regional Council. Enjoy |
| Upcoming Relive LIVE: Learn How to Maintain Hydraulic Capacity of Culverts & Protect the Fish Thursday, April 29th @ 8:30am PT / 11:30am ET (USA). Note this time may not suit so we will post a link to a recording once done. |
| Learn how installing flexible culvert baffles is an easy and inexpensive method to improve fish passage through culverts. Salmon, trout and other fish and aquatic species are often blocked from their habitat by poorly designed or constructed culverts. Repairing or removing culverts is costly and requires considerable time and resources. SSA Environmental LLC has developed culvert baffles that improves fish passage in an effective and economic manner. |
Watch Tim’s latest video showing young eels trying to climb a concrete weir only to be swept off by pulses of water, making an already difficult climb impossible.
Sometimes the variations in flowing water can be beneficial or disadvantageous to migrating fish, and in this case it is causing all sorts of problems!”
youtube link
https://www.youtube.com/watch?v=0taQYS-TmPw
Hi everyone
Below is a brief report following remediation of two culverts at Raumanga, Northland, NZ.
An ‘after remediation’ fish survey was undertaken on the Raumanga fish passage remediation project in mid-December 2020, and to keep in line with the 2019 survey, we undertook both electric fishing and gee minnow trapping. Similar biodiversity and abundance were found in the electric fishing reaches (long fin eels, short fin eels, juvenile eels, red fin bullies, torrent fish, smelt) with many schools of smelt observed both above and below barrier number 1 (Bernard St). We also caught 1 īnanga (galaxiid maculatus) in a gee minnow immediately upstream of the remediated barrier – success! As I am sure you are all aware, īnanga are thought to have the weakest ‘climbing’ abilities when navigating structures, so to find a young īnanga on the upstream site of the first barrier was a wonderful result.
Remediation consisted of installing flexi-baffles in the barrels of all culverts, rubber ramps and ropes on the outlets and cascading outlet areas.
We also visited the next barrier upstream (Tarewa I-site) and were thrilled to see natural bed material retained in the base of the true right culvert ( see picture below). This is the perfect outcome as it means the velocity is slow enough for natural substrate to be retained in the pipe, which is good news for fish movement and of course macroinvertebrate habitat for the fish to snack on, on the way up.
Overall, Riffle Restoration and the Whangārei Harbour Catchment Group are really happy with these results. Long may the native fish migrations continue!
For more info contact
Jordan MacDonald
Riffle Restoration
0273548745
 A nice layer of bed material has built up between the baffles. |
