Standard Talk (15 mins) Australian Society for Fish Biology Conference 2022

Recent advances to lift fish safely across barriers with Tube Fishways (#129)

Stefan Felder 1 , William Peirson 1 , John H Harris 2 , Richard T Kingsford 2 , Maryam Farzadkhoo 1 , Reilly Cox 1 , Hiruni Kammanankada 1 , Iain M Suthers 2
  1. Water Research Laboratory, School of Civil and Environmental Engineering, UNSW Sydney, Manly Vale, Australia
  2. Centre for Ecosystem Science, School of Biological, Earth and Environmental Sciences, , UNSW Sydney, Kensington, NSW, Australia

Dams and weirs fragment riverine ecosystems and disrupt natural fish migration leading to a depletion of fish populations. Fishways are installed to allow upstream fish migration, with proven success for low-head barriers. These fishways are expensive, limiting the number of barriers with installed fishways. Very few large barriers such as dams have fishways installed because available solutions such as fish lifts are often unreliable and very expensive. An innovative Tube Fishway was developed by a multidisciplinary research team from UNSW Sydney as a cost-effective alternative to enable fish migration across low- and high-head barriers. Laboratory trials have demonstrated fully automated operation of the Tube Fishway.

The Tube Fishway operates cyclically via: (a) attraction of fish into the transfer chamber, (b) lifting of fish with an unsteady surge at near-atmospheric pressure, and (c) an enabling sequence of valve operations. Large numbers and different sizes of Australian native fish (silver perch Bidyanus bidyanus and Australian bass Percalates novemaculeata) have been reliably attracted and lifted safely vertically by 4 m. A systematic study investigating fish condition in closed conduit systems is developing guidelines for safe operation of Tube Fishways for fish. Field trials are currently underway.

The Tube Fishway and its implementation continues to develop and improve with focused laboratory and field research, providing considerable promise for solving a global problem for river ecosystems.