Data abstract:

Data on the valve gape of mussels and the behaviour of stimulus crabs during sound exposure trials. We provide the raw valve gape data, processed data, and scripts to process the raw data, make plots, and run the statistics.

Paper abstract:

Noisy human activities at sea are changing the acoustic environment, which has been shown to affect marine mammals and fishes. Invertebrates, such as bivalves, have so far received limited attention despite their important role in the marine ecosystem. Several studies have examined the impact of sound on anti-predator behaviour using simulated predators, but studies using live predators are scarce. In the current study, we examined the separate and combined effects of boat sound playback and predator cues from shore crabs (Carcinus maenas) on the behaviour of mussels (Mytilus spp.). We examined the behaviour of the mussels using a valve gape monitor and scored the behaviour from the crabs in one of two types of predator test conditions from video footage to control for effects from potential, sound-induced variation in crab behaviour. We found that mussels closed their valve gape during boat noise and with a crab in their tank, but also that the stimulus combination did not add up to an even smaller valve gape. The sound treatment did not affect the stimulus crabs, but the behaviour of the crabs did affect the valve gape of the mussels. Future research is needed to examine whether these results stand in situ and whether valve closure due to sound have fitness consequences for mussels. The effects on the well-being of individual mussels from anthropogenic noise may be relevant for population dynamics in the context of pressure from other stressors, their role as ecosystem engineers, and in the context of aquaculture.

We collected valve gape data of mussels using a custom made valve gape monitor. The behaviour of the crabs was visually scored from video footage.

All scripts and data can be opened using R (R Core Team). The sound recordings can be opened using Audacity (The Audacity Team).