Migrating fish will travel upstream to spawn, once completed their lifecycle they will die off and then new generation will hatch and swim downstream to start the process all over again.
These seems pretty straight forward until you throw the odd beaver dam or two in the mix strategically placed and meticulously built along the same water course as the travelling fish. These dams may be considered as a barrier interfering with or preventing the remainder of the journey for spawning adults or the return downstream journey of young fish.
The battle between species conservation is a well worn path and point of discussion between "fish people" and "beaver people" in particular as to whether the dams should or shouldn't be removed.
This is where fish passage comes in.
Natural fish passage is well documented with studies reporting salmon and trout using higher water flow to ascend dams while the small rivulets at the ends of dams have been shown to help juvenile fish migrate however where passage is slowed or halted is during low water periods.
To address migratory issues while maintaining beaver habitats, fish ladders (also referred to as fish passage/fish elevator/fish lift) can be developed and implemented.
They provide several benefits ensuring the preservation of beaver-generated ecosystems while addressing migratory concerns. Fish ladders can be particularly advantageous during low water periods and when human infrastructure have created pinch points in water courses.
Considerations
Effective fish passage requires expertise to understand the needs of the local fish species, implementation of beaver flow control devices and relevant monitoring and maintenance to ensure long term effectiveness. Contact our beaver management specialists for a solution custom to your site.