In Situ Mortality Experiments with Juvenile Sea Bass (Dicentrarchus labrax) in Relation to Impulsive Sound Levels Caused by Pile Driving of Windmill Foundations

Abstract

Impact assessments of offshore wind farm installations and operations on the marine fauna are performed in many countries. Yet, only limited quantitative data on the physiological impact of impulsive sounds on (juvenile) fishes during pile driving of offshore wind farm foundations are available. Our current knowledge on fish injury and mortality due to pile driving is mainly based on laboratory experiments, in which high-intensity pile driving sounds are generated inside acoustic chambers. To validate these lab results, an in situ field experiment was carried out on board of a pile driving vessel. Juvenile European sea bass (Dicentrarchus labrax) of 68 and 115 days post hatching were exposed to pile-driving sounds as close as 45 m from the actual pile driving activity. Fish were exposed to strikes with a sound exposure level between 181 and 188 dB re 1 µPa2.s. The number of strikes ranged from 1739 to 3067, resulting in a cumulative sound exposure level between 215 and 222 dB re 1 µPa2.s. Control treatments consisted of fish not exposed to pile driving sounds. No differences in immediate mortality were found between exposed and control fish groups. Also no differences were noted in the delayed mortality up to 14 days after exposure between both groups. Our in situ experiments largely confirm the mortality results of the lab experiments found in other studies.

Effects of marine noise pollution on Mediterranean fishes and invertebrates: A review

“…Significant effects of pile driving noise on oxygen consumption and grouping behavior have been mostly detected on confined individuals following exposure to the "real" pile driving noise in the natural environment (Santulli et al, 1999;Bruintjes et al, 2016a;Debusschere et al, 2016;Hawkins et al, 2014). On the contrary, the studies where no effect has been observed used playbacks records of real noises emitted either in aquaria or in the field (Bolle et al, 2012;Debusschere et al, 2014;Bruintjes et al, 2016b;Radford et al, 2016). The two exceptions reviewed here are the case of European plaice directly exposed to the real pile driving noise, where no detectable effects on oxygen consumption have been reported (Bruintjes et al, 2016b), and the modification of structure and dynamics of shoals of European seabass reported in aquaria (Herbert-Read et al, 2017).…”

“…Swimming speed and depth / Kastelein et al,. (2007) Dicentrarchus labrax / Primary and secondary stress response Debusschere et al, (2014Debusschere et al, ( , 2016 Fish shoal behavior (cohesion, direction, coordination) / Herbert- Read et al, (2017) Startle response, swimming speed and depth and group cohesion / Neo et al, (2014) Swimming patterns / Neo et al, (2015) Swimming speed and depth / Neo et al, (2016) / Ventilation rate Radford et al, (2016) Startle response, swimming behavior Cortisol, glucose, lactate, AMP, ADP, ATP and cAMP Santulli et al, (1999) Swimming speed and depth / Kastelein et al,. (2007)…”

The impact of experimental impact pile driving on oxygen uptake in black seabream and plaice

“…In fish species, experiments have been conducted using several methods of acoustic exposure including: (1) playbacks of recorded sounds (Smith et al, 2004;Wysocki et al, 2006;Radford, 2013, 2014), (2) real boat or ship passes (Sarà et al, 2007;Graham and Cooke, 2008;Jacobsen et al, 2014;Simpson et al, 2016), (3) seismic airguns (Engas et al, 1996;Popper et al, 2005;Miller and Cripps, 2013;Thompson et al, 2013), and (4) impact pile driving (Debusschere et al, 2014(Debusschere et al, , 2016.…”

“…Dähne et al, 2013, Debusschere et al, 2014. Moreover, many elements will influence the sound intensity, amplitude and frequency structure of the sound during pile driving including the pile's physical quantities, hammer type, pile driving method, strike rate, water depth, and the substrate of the area the pile is being installed.…”

“…Studies using juvenile European sea bass (Dicentrarchus labrax) and in situ pile driving, have shown a decrease in oxygen uptake (a secondary stress response), and no impact on mortality (Debusschere et al, 2014(Debusschere et al, , 2016. Other studies, using sound playbacks have reported an increase in primary and secondary stress characteristics, including increased oxygen consumption, higher ventilation rates and increased blood cortisol levels (Smith et al, 2004;Wysocki et al, 2006;Simpson et al, 2015;Bruintjes et al, 2016;Purser et al, 2016).…”