ESM 5 from Marine soundscape shaped by fishing activity

Marine communities face anthropogenic pressures that degrade ecosystems. Because underwater soundscapes carry information about habitat quality, we explored whether destructive impacts of fishing could be evaluated via the soundscape. Maerl beds are recognized as biodiversity hotspots and they experience major worldwide degradation due to fishing. We collected field acoustic recordings in maerl beds exposed to different fishing practices. We found that unfished maerl beds were threefold louder and exhibited sound frequencies more diversified than those recorded in fished maerl beds. Analyses of associated fauna samples indicated that snapping shrimps provided a major contribution to the maerl bed soundscape. Moreover, sea urchins and squat lobsters most likely contributed to differences between the soundscapes of unfished and fished maerl beds. Our results supported the idea that the soundscape can provide valuable information on maerl bed ecosystem health related to fishing activity.