While dams are being built to provide more renewable energy to the world and trying to prevent the release of greenhouse gases, the fish who swim near these dams are at stake of dying.
The main concern is the harm caused to salmon traveling up river to spawn and downriver as juveniles when they return to the ocean. When these salmon navigate the water near dams, they are often injured or killed from fish ladders, bypasses, turbines, and unnaturally warm swimming areas.
To try and mitigate the consequences these fish face, scientists at the Pacific Northwest National Laboatory (PNNL) hope to make the quest through the waters less life-threatening with robotic fish. Their technology measures physical impacts of hydropower infrastructure on the fish and tracks salmon migration.
PNNL has created what they’re calling Sensor Fish, a look-alike fish that’s approximately 3.5 inches long and about the size of a juvenile salmon. The Sensor Fish is released into the water at the top of a dam and travels through it, while collecting information on pressure, acceleration, rotational velocity, and orientation. The device takes about 2,000 measurements per second and is then recovered below the dam.
The sensors are reusable and are being manufactured by Advanced Telemetry Systems (ATS).
PNNL has also created an injectable tracking device that can be injected into young salmon to monitor their migration for up to three months. The acoustic transmitter is approximately double the size of a grain of basmati rice. Unlike the robotic fish, these are not reusable.
The researchers hope the data from both devices can provide information for dam engineers and help operators design hydropower plants with fish in mind.
“There is a big need for the type of data provided by the Sensor Fish,” says ATS president Peter Kuechle. “Mature hydropower industries in the U.S. and Europe hope to modify operations in order to help fish survive. In Europe, regulations insist on testing for this information, and certainly there’s a need for the data in emerging hydropower projects globally.”
Although not all are sure this will completely save both the salmon and orcas who feed on them, the researchers hope the new tech can help gather more information and provide a better design for operations inhabiting marine life.