Spawning areas and spawning grounds are often missing in affected watercourses because gravel and finer materials have been washed away. For the same reason, it can be difficult to find suitable material for establishing spawning grounds. Here, we list some options.
- Excavate; sometimes you can find finer fractions in the substrate by breaking through the stone layer. It can be challenging for the excavator to get through the stone layer, but persistence can lead to generous rewards. If there is a lot of blasted rock in the watercourse, there is a significant risk of retrieving large amounts of blasted material from the bottom, which you should be prepared to manage. This method may be best suited for individual spawning grounds.
- Local environment; if you’re lucky, you may find suitable material on land. This is a good option if you have blasted rock that you want to dispose of, as it can be buried on land.
- Downstream calm areas and pools. Here, finer materials often accumulate as the energy of the water decreases. If it is close to the intended spawning grounds, it may be worth retrieving this material with the excavator.
- Helicopter; if there is no suitable material available, a helicopter can be used. Preliminary work should be completed with the excavator, and the location marked to facilitate placement at a later stage. Of course, it is desirable to use material from the local area as much as possible.
Regardless of where the material is sourced from, the fundamental principle for establishing the spawning ground remains the same.
