The effects of simulated hydropower turbine rapid decompression on two Neotropical fish species

• DOI: 10.1016/j.scitotenv.2023.166770
• Publication Date: 2023-09-01T15:14:06Z
• Authors: J.R. Kerr; A.L.F. Castro; N.O. Melo; J.A. Daniels; A. Holgate; L.A. Dolman; L.G.M. Silva; P.S. Kemp
• Keywords: Swim bladder

Barotrauma is a major cause of injury and mortality fish as they pass through hydropower turbines. Current understanding related barotrauma biased towards northern temperate southern subtropical species with single chambered swim bladders, specifically North American Australian species, respectively. Today, unprecedented development taking place in Neotropical regions where many have complex multi-chambered bladder architecture. This study investigated two dual-chambered physostomous (pacu, Piaractus mesopotamicus, piracanjuba, Brycon orbignyanus) exposed to rapid (< 1 s) decompression at different Ratios Pressure Change (RPC), using hypo-hyperbaric chamber. The incidence intensity (percentage surface area organ affected) physiological behavioural response (hereafter just response) each immediately after was assessed. Twenty-two types (e.g. gill haemorrhage exophthalmia) eight categories rising the loss orientation) were identified influence of: 1) 2) RPC, 3) rupture on quantified. There considerable interspecific difference emboli type injuries occurring more frequently but tending be higher pacu. Both chambers tended piracanjuba only anterior chamber RPC positively correlated response, several for both some very low 50 % probability 2.2 1.75 pacu, respectively). Multiple responses eye haemorrhage) suggesting gas venting into body cavity likely causes secondary injury. When directly comparing our results those available published literature, pacu appear susceptible than previously studied species.