Underlying mechanisms of movement patterns in cyprinids affected by hydropeaking  — ASN Events

Underlying mechanisms of movement patterns in cyprinids affected by hydropeaking  (#86)

Maria Costa 1 , Isabel Boavida 1 , António N. Pinheiro 1
  1. Instituto Superior Técnico, Universidade de Lisboa, Lisbon, Portugal

Hydropower production results in daily energy peaks with the release of artificial discharge peaks downstream the hydropower plant, with subsequent negative effects on the abiotic components and the biological communities of the river system. Despite the growing awareness of hydropeaking impacts in the fish biota, it is still largely unknown how fish react and behave under peak events. Moreover, hydropeaking studies have been dominated by fast-flowing salmonids, and very few information is available on behavior of cyprinid species, an important biological component of fish assemblages with some of the species being at risk due to human-induced impacts. In this work, the movement behavior of cyprinids was tested when exposed in an artificial flume (8 m long, 0.7 m wide, 0.8 m high) to different cycles of pulsed peak flows. Fish organism level responses and movement behavior were assessed for different conditions of flow ratio, rate of water level change; and frequency of peak flows. Results indicate that fish movements are triggered by discharge fluctuations. This work improves the knowledge and understanding of fish behavior under hydropeaking conditions and associated environmental causes that will contribute to a more sustainable hydropower management.

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