Whales, dolphins, squid and fish are among the many marine species that rely on underwater sounds for everything from foraging to communication. By listening to what’s happening in the water around them they able to orientate themselves, locate prey, avoid predators or even select a mate.
But the underwater sonic landscape is changing. It’s being affected by commercial shipping, sonar systems used by the navy, for example, or by fishing industries to locate fish schools and blasting for construction. Marine seismic surveys – which explore subterranean geological features for petroleum, natural gas and mineral deposits – are also becoming more common in response to the world’s growing energy demands.
These extremely loud man made underwater noises can harm marine animals. Seismic surveys can cause barotrauma in fish, which is the damage of tissues due to rapid changes of pressure following the loud sounds wave travelling through the water. Fish eggs that are laid in the vicinity of seismic surveys are also more likely to die off. And recent research has shown that more zooplankton dies near seismic surveys. These are the tiny animals that form the base of the marine food chain, underpinning entire oceans’ productivity. All of this means that seismic surveys can have serious consequences on marine ecosystems.