
Downstream migrating fish want to go with the flow, but hydropower infrastructure can block or alter migration routes, resulting in fish injury or mortality. Traditional approaches to fish protection aim to exclude fish from entering turbines using fine screens, and to route fish around turbines with low- flow fishways.
However, screening can be ineffective, allowing some fish to pass through and suffer injuries or death in conventional turbines, or harming fish that become impinged on screens or are subject to predation while exposed in fish bypasses. Screening and bypass reaches are also infrastructure and maintenance-intensive, resulting in higher Capex and Opex costs to plant owners as well as reduced plant efficiency due to flow-limiting screens.
Natel's FishSafe™️ RHT designs offer a truly fish-safe option, enabling numerous fish species to pass through multiple dams consecutively, and freeing owners of the need to exclude fish from their plants.
Effective passage for fish and other aquatic life is a key part of maintaining clean water for drinking and irrigation. The dynamic relationship between fish and freshwater mussels is one example of why connectivity matters.
In the same way that pollinators support terrestrial ecosystems, freshwater mussels provide essential ecosystem services for rivers and lakes including water filtration, habitat stabilization, and nutrient cycling. A single mussel can filter up to 15 gallons of water a day, reducing concentrations of algae, bacteria, diseases, heavy metals, and pharmaceuticals, as well as industrial runoff.
Mussel larvae attach to the gills of a host fish where they can filter nutrients and complete their development before dropping to the river or lake bed in a new location.