Falling on deaf ears: The neglected consequences of marine noise pollution

The ocean, despite traditionally being referred to as the “silent world,” is an environment that is louder than many believe. One of the most often overlooked consequences of an increasingly globalized world is oceanic noise pollution and its negative impact on marine life. Marine ecosystems have already been placed in a precarious position due to decades of chemical, plastic, and carbon pollution. Managing marine noise pollution, while less salient in the general discourse on environmental pollution, should also be included within the scope of efforts to maintain ecological balance. Merchant shipping, sonar and seismic surveys, which are used to locate underwater resources and mining operations are not only disrupting communications between species and causing them harm, but in some instances are outright killing them.

Marine noise pollution is affecting species of all shapes and sizes, from large mammals like whales and dolphins, who rely heavily on echolocation, to thousands of other smaller species. Larvae are particularly vulnerable to its effects and can even develop mutations as a result. A study conducted in 2017 found that when energy companies use air gun blasts to locate energy pockets, the concentrated “low frequency, acoustic impulse signals” killed the majority of plankton and krill larvae caught in the crossfire. Seismic air guns are the most common method of ocean mapping, and work by repeatedly blasting pressurized air onto the seafloor. The recent initiative by the Trump administration to allow new offshore oil and gas drilling in American coastal waters means that seismic mapping will occur more frequently. Given that many of the vulnerable species serve as the building blocks of marine food chains and are vital for the health of oceanic ecosystems, their absence will be felt by all other species. 

In addition to seismic air guns, commercial shipping has long been recognized as one of the main sources of anthropogenic marine noise pollution. Opening trade routes in the Arctic are of particular concern, as the relatively pristine waterways now have the potential to be used as a shortcut between the Arctic and Pacific oceans. The maritime component of China’s Belt and Road Initiative, known as the “maritime silk road,” will also drastically increase marine noise disturbance around the world.

While marine noise pollution does not directly affect human health, its indirect consequences are concerning and should be addressed immediately by the international community given the global dependence on healthy marine ecosystems. Roughly ten per cent of the world’s population is dependent on fishing and fishing-related activities for their livelihood, while marine life serves as a significant source of daily protein for over 60 per cent of the population. Decades of detrimental fishing practices have already decimated global fish stocks, and marine noise pollution is an exacerbant that threatens an already-fragile aquatic environment. This is made even worse by the expansion of shipping routes and increases in the number of ships. Despite this increasing vulnerability, not enough is being done to preserve and protect marine soundscapes.

The United Nations has pledged to sustainably use the oceans, seas and marine resources for future development under Sustainable Development Goal 14 – part of its 2030 Agenda for Sustainable Development. However, the international community needs to directly target a reduction in marine noise pollution. One way in which this can be achieved is through the widespread advocacy and adoption of quieter propulsion systems. Not only will the standardization of quieter propellers reduce noise pollution, but it will also make ships more fuel efficient, thereby not only reducing theirs fuel costs but also reducing the ships’ carbon footprints. Nevertheless, the health and well-being of marine environments and their organisms should not be second to economic motives. The global community needs to develop sustainable approaches to marine trafficking in order to provide short-term relief for the millions of organisms that rely on undisturbed marine soundscapes, in addition to considering long-term economic and sustainable outcomes.