Add crabs, and perhaps by extension other crustaceans, to the list of animals negatively affected by shipping noise in the world’s oceans.
A new study has found that ship noise markedly changes some important crab behaviors:
Working with the same common shore crabs that children delight in catching on crablines in UK harbours, the team found ecologically-critical effects of ship noise-playback on behaviour.
Matt Wale from the University of Bristol said: “Crabs feeding on mussels were often distracted when ship noise was playing compared to quiet harbour recordings. Furthermore, crabs took longer to retreat to shelter after simulated attacks in noisy treatments, and if turned upside-down they flipped back far quicker in noisy conditions rather than turning slowly to avoid attracting attention of potential predators.”
Dr Steve Simpson from Biosciences at the University of Exeter said: “We have already found that ship noise raises the metabolic rate and energetic needs of crabs. If coupled with reduced foraging and worsened responses to predators, this cocktail of impacts may negatively affect growth, fitness, survival and, ultimately, harvested populations and whole ecosystems.”
Cetaceans (whales and dolphins), fish, and larvae of reef creatures have previously been found to respond to shipping noise in ways that can increase energy expenditures and stress levels; this is the first clear indication that crustaceans are also negatively affected.