Safe passage of American Eels through a novel hydropower turbine

Published source details Watson S., Schneider A., Santen L., Deters K.A., Mueller R., Pflugrath B., Stephenson J. & Deng Z.D. (2022) Safe passage of American Eels through a novel hydropower turbine. Transactions of the American Fisheries Society, 151, 711-724.
Share Tweet Email

This study is summarised as evidence for the following.

	Action	Category
	Modify design of underwater turbines Action Link

Modify design of underwater turbines

A replicated study in 2021 at an experimental facility in California, USA (Watson et al. 2022) found that all American eels Anguilla rostrata that passed through a modified turbine survived, but some experienced gill haemorrhaging. In each of two trials, all of 47–84 eels (100%) that passed through a modified turbine survived. In one of the two trials, a greater proportion of eels that passed through the turbine had gill haemorrhaging (15 of 84 eels, 18%) compared to control eels that did not pass through (0 eels). The difference was not significant in the other trial (gill haemorrhaging: 3 of 47 'turbine' eels [6%], 0 control eels). The proportions of eels with eight other injury types did not differ significantly between 'turbine' eels (0–67%) and control eels (0–69%) in both trials (see paper for details). In August–November 2021, in each of two trials, captive-reared eels (34–66 cm long, 47–84 eels/trial) were tagged and individually released from an injector chamber into a pipeline to pass through a modified 'Restoration Hydro Turbine' (‘Natel’ design). The turbine (55-cm outer diameter) had three blades with a 55-mm leading edge and a blunt, forward-swept face. For comparison, control eels (14–29 eels/trial) were released into the pipeline downstream of the turbine. All eels were recaptured, examined for injuries, and kept in a holding tank for 48 h.

(Summarised by: Anna Berthinussen)