Passage performance and behaviour of wild and stocked cyprinid fish at a sloping weir with a Low Cost Baffle fishway

Lothian, A. J., Gardner, C. J., Hull, T., Griffiths, D., Dickinson, E. R. and Lucas, M. C. (2019) Passage performance and behaviour of wild and stocked cyprinid fish at a sloping weir with a Low Cost Baffle fishway. Ecological Engineering, 130, pp. 67-79. (doi: 10.1016/j.ecoleng.2019.02.006)

Abstract

Weir construction has fragmented many rivers, resulting in the exclusion of some fish populations from suitable habitat. A cheap retrofit fishway for small, sloping weirs is the Low Cost Baffle (LCB) solution – A series of notched baffles perpendicular to flow on the downstream weir face, generating an angled passage route across the weir face. To test the degree to which LCBs can pass upstream-moving, lowland-river fish at steep weirs, LCBs were fitted onto a 1:3.3-sloping gauging-weir face, in an urban tributary of the River Thames, England. The study also compared the passage of wild and stocked fish (the latter are employed to facilitate population recovery in restored English rivers). Passive Integrated Transponder (PIT) antennas were positioned on the weir to record the upstream movement of PIT-tagged barbel (Barbus barbus; nstock = 120), chub (Squalius cephalus; nstock = 119; nwild = 194), dace (Leuciscus leuciscus; nwild = 50), and roach (Rutilus rutilus; nwild = 30). Over six months, more stocked fish attempted passage (58.9%) than wild (14.6%; χ21 = 26.7, p < 0.001), but there was no difference in successful passage of those that attempted (stock = 34.0%; wild = 40.0%; χ21 = 0.5, p = 0.49). Successful passage was achieved under a range of flow conditions. This study finds that LCBs have the potential to facilitate passage for cyprinid fishes at steep urban weirs that cannot readily be removed, but there is need for design improvements. This study also indicates that stocked and wild fish exhibited similar passage success, a finding with important management implications for achieving dispersal of stocked fish as a rehabilitation measure.

• Item Type: Articles
• Additional Information: Funding for LCBs was provided by the EA. AJL and MCL were partly supported by the EU AMBER (Adaptive Management of Barriers in European Rivers) project, Grant Number: 689682.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Dickinson, Ms Eleanor and Lothian, Dr Angus
• Authors: Lothian, A. J., Gardner, C. J., Hull, T., Griffiths, D., Dickinson, E. R., and Lucas, M. C.
• College/School: College of Medical Veterinary and Life Sciences > School of Biodiversity, One Health & Veterinary Medicine
• Journal Name: Ecological Engineering
• Publisher: Elsevier
• ISSN: 0925-8574
• ISSN (Online): 1872-6992
• Published Online: 14 February 2019