What are fish passes & why do they matter?

The four fish passes installed as part of DNAire will reconnect the river across on the last four high weirs on the River Aire.  These weirs are the last hurdle in the salmons dramatic journey from the realm of polar bears, whales and early Viking explorers in the North Atlantic back to place of their birth in shallow, gravelly streams in the Dales to spawn.

These new fish passes are also designed to allow eels, lamprey and other coarse fish to move up and down the river.

Larinier fish pass modules
Larinier fish pass baffles that sit in the floor of a fish pass

Where will we do the work?

Fish passes will be built on four weirs:

Newlay (in Horsforth)

What are fish passes?

Fish passes are needed where weirs interrupt the river habitat.  The weirs we plan to work on are too high or too steep for fish to swim up.  Fish passes break the journey up the weir into shorter, less steep sections for the fish to take one at a time.  Our Larinier fish passes have metal baffles sit in the bottom of a concrete channel that break up the flow of water.

Why do they matter?

Want to know more?

We have written a series of frequently viewed questions that can be viewed here.

To find out more about why we need fish passes and the different types that can be built head to the Environment Agency’s website.