While many people think of oceans when they think of fisheries, nearly half of the world’s fish species live in freshwater rivers, lakes, and wetlands, even though those represent less than 0.01% of the Earth’s water.
In fact, despite the comparatively tiny footprint of freshwater bodies, freshwater ecosystems are the source of more than 40% of all fish consumed globally, according to the WWF. Additionally, many of the fish tallied as marine catch are caught in estuaries — where river-borne sediment brings important nutrients — meaning that the health of freshwater ecosystems is directly connected to even more of the world’s fish-based food supply.
According to a 2016 UN report, global fish consumption has been growing steadily in the last 50 years — at double the rate of population growth. At the same time, the report noted, freshwater fishery yields and freshwater ecosystem services have been repeatedly undervalued in policy discussions that ruled in favor of “hydropower, irrigation and industry.”
While there are many causes of declining fisheries worldwide, hydropower and non-powered dams are in part to blame. As Jeff Opperman rightly notes in "Connections Matter: The Importance Of Freshwater Connectivity," the impact that dams have had on river connectivity globally poses a significant threat to migratory fish, river ecosystems, and, as a result, food security.
It’s clear that protecting the world’s fisheries, reestablishing river connectivity and protecting freshwater biodiversity are all imperative. It is equally important that we leverage existing renewable energy technologies and deploy new solutions to rapidly reduce carbon emissions and limit global temperature rise.
At Natel, we’re working to balance these two objectives by enabling downstream fish passage while producing renewable energy. Integrating FishSafe hydropower turbines into existing hydropower plants or into non-powered dams, where they help improve lateral river connectivity, can support the restoration and growth of our fisheries while also addressing the pressing issue of climate change.
In this video, Research Engineer Simone Lassar takes you through a quick tour of our recirculating aquaculture system (RAS) — an essential part of our laboratory that supports our FishSafe turbine design and validation process.
Fish acclimate in the RAS before participating in through-turbine fish passage tests at our hydraulic test facility. During testing, fish are injected into the closed-loop system upstream of a scale-model turbine. Control fish are injected into the loop system downstream of the turbine. After testing, both turbine-passed and control fish remain in the RAS for a period of time for observation.
In the last year a variety of fish — including trout, freshwater eels, and catfish — have cycled through our lab, demonstrating 98-100% survival after passing through Restoration Hydro Turbines (RHTs), which are designed for fish safety.
We are privileged to be able to conduct live fish passage testing and grateful to the fish that support our efforts to design turbines that are truly safe for fish will help sustain fisheries worldwide while also producing necessary renewable energy.
StromLinie, an Austrian power magazine, writes about Energie Steiermark's next-incubator team and how they chose the RHT for their Sauerbrunn Hydro Plant.
An AUMA electric actuation solution ensures high-precision guide vane adjustment for a fully-submersible hydro turbine from Natel Energy at the Sauerbrunn hydropower plant.