Flow in nature-like fishway and its relation to fish behaviour

• Published in: Canadian journal of civil engineering Vol. 40; no. 6; pp. 567 - 573
• Main Authors: BRETON, F, BAKI, A. B. M, LINK, O, ZHU, D. Z, RAJARATNAM, N
• Format: Journal Article
• Language: English
• Published: Ottawa, ON NRC Research Press 01.06.2013; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: ADV; Applied sciences; Boulders; Buildings. Public works; Comparative analysis; Doppler effect; débitmètre acoustique; Ejection; Environmental aspects; Exact sciences and technology; Fish; Fish behavior; fish habitat; Fish ladders; Fish migration; fish passage; Fishes; flow; Fluid dynamics; Flumes; habitat du poisson; Habitats; Hydraulic constructions; Hydraulic measurements; Measurement; nature-like fishways; passe migratoire; passes migratoires d'aspect naturel; Physiological aspects; Spatial analysis; Speed; turbulence; Turbulent flow; Wakes; écoulement; Canada; Fishpass; Turbulence; Hydraulics; Migration; Experimental device; Experimental study; Acoustic method; Vertebrata; Flowmeter; Flow(fluid); Pisces; Shear stress; Flow velocity; Habitat
• ISSN: 0315-1468; 1208-6029
• DOI: 10.1139/cjce-2012-0311

Experimental results on the nature-like fishway induced flow field and its relation to fish behaviour are presented. A rocky-ramp with 5% slope was built along a 8.9 m × 0.9 m × 0.6 m laboratory flume, and acoustic Doppler velocity measurements were taken in a grid with 186 points for low, middle, and high discharges. The flow is characterized applying spatial and point analysis techniques. Point analysis consistently shows that the boulder to boulder distance is small enough to disrupt turbulent coherent structures. At boulder wakes no predominance of sweep and ejection events occur, evidencing a good resting place for fish migration. The nature-like rocky-ramp offers a diversity of flow conditions controlled by the boulders geometry that might allow a variety of fishes to develop their preferred paths characterized by flow properties with different magnitudes depending on the particular species. Obtained results compare well with similar ones reported for other standard fishways.