Scientists recently developed a new, tiny battery and tag to track younger, smaller species, such as salmon, eel, and Pacific lamprey. This new information can be used to develop ways to protect young fish and support survival during downstream migration.

In a study published in Cell Reports Physical Science, researchers from Pacific Northwest National Laboratory (PNNL) describe an injectable acoustic tag, called the Eel/Lamprey Acoustic Tag (ELAT), which is about the size of a grain of rice and holds twice the energy of a AAA battery.

"This tag opens up possibilities to track movement of a variety of species and life stages that we were previously unable to study," said Daniel Deng, a Laboratory fellow and mechanical engineer who led the battery and tag development.

It also gives even more insight to support sustainable hydropower by following fish passage in and around hydropower facilities for sensitive species. Tagging very young species informs future design and operations of hydropower. This information can be used to develop technology and improve environmental performance, while still providing clean, reliable power.