Ocean Noise Pollution

Transcription

1 Factsheet Ocean Noise Pollution Summary Scott Portelli Ocean noise pollution from a number of human activities has greatly increased throughout the global oceans in recent decades. Commercial shipping, seismic surveys for oil and gas exploration, and pile driving for offshore construction all cause substantial underwater noise pollution. Although human-generated underwater noise is recognised as a source of marine pollution and a threat to marine ecosystems by the United Nations, there is currently no international regulation of ocean noise. This pollutant threatens marine life, including whales and dolphins, but much of this noise pollution has no function and could easily be avoided. Unlike other forms of marine pollution, when ocean noise stops the pollution stops. IFAW aims to reduce global underwater noise pollution by increasing awareness and promoting measures to reduce the source levels of noise. IFAW also advocates for the removal of the noisiest activities from important whale habitats. Ocean Noise Pollution Factsheet

2 Background It is now widely accepted that ocean noise pollution has negative impacts on marine life, and steadily increasing underwater noise from industrial activities, such as shipping, drilling and seismic exploration, is a growing concern for marine conservation. Marine mammals, such as whales and dolphins, are particularly vulnerable to the impacts of ocean noise pollution as they rely on underwater sound for survival; it is essential for communication, navigation, locating prey, avoiding predators and finding potential mates. However, increasing ocean noise pollution is causing stress and reducing the ability of these animals to carry out essential life functions. Exposure to underwater noise can result in both temporary and long-term impacts for marine life. The impacts of ocean noise on marine mammals include forcing them out of their preferred habitat, drowning out vital sounds used for long-range navigation and communication, and behavioural or physiological (stress) responses. All of these compromise welfare and may have populationlevel effects. Other marine life, such as fish and crustaceans, are also impacted. Noise pollution may also affect human activities and fishermen have reported lower catches following noisy activities. Shipping Noise Up to 90% of the world s cargo is transported by sea, and between 1980 and 2009 the global merchant shipping fleet almost doubled in capacity. In many areas, ocean noise pollution from shipping activities has greatly increased ambient noise levels, degrading the quality of acoustic habitat for marine life. Sonic Sea/Imaginary Forces For large ships, propeller cavitation (caused by collapsing air bubbles) generates most of the underwater noise produced. Inefficient hull and propeller design are the main causes of excessive cavitation and thus higher noise levels, but this is highly dependent on ship speed and in general, slower ship speeds will tend to reduce noise from this source. Reducing ship speeds can significantly reduce fuel costs, greenhouse gas emissions and underwater noise, benefitting both the shipping industry and the environment. Further benefits exist for the shipping industry to reduce environmental impacts through port-based incentive schemes. For example a number of ports, including Rotterdam, Hamburg and Lisbon, offer considerably reduced port dues for ships with higher ESI (Environmental Ship Index) scores through the Green Award scheme. The ESI scores ships that perform better in reducing gas emissions than the current emission standards asked for by the International Maritime Organization (IMO) and helps in identifying greener vessels more generally. Up to 90% of the world s cargo is transported by sea Factsheet Ocean Noise Pollution

3 Ocean Noise: Turn it down Whales and dolphins rely on underwater sound for their survival Ocean noise pollution causes stress and reduces their ability to: Communicate W N E Navigate S Locate prey Other marine life, such as fish, crustaceans and squid are also impacted Avoid predators Find potential mates Underwater noise from ships comes from Engines and machinery Hull vibrations but is mainly caused by 1 ) poor propeller design 2) dirty or damaged propeller 3) propeller not optimised for design or speed of ship 4) Poor ship hull design and uneven water flow into propeller Noisy propeller = ship operating inefficiently Solutions to reduce noise Slower ship speeds Build new ships with optimised noise reduction design Existing ships 1 ) install new, more efficient propeller 2) regular propeller maintenance (clean propeller, repair damaged blades) 3) fit devices to improve water flow to propeller 4) good hull maintenance

4 Reducing noise from shipping Global guidelines and legislation The IMO has recognised the need to act to reduce noise pollution from shipping. In 2014 the IMO adopted guidelines for reducing underwater noise alongside fuel efficiency measures across its fleets (MEPC.1/Circ.883). These guidelines can be applied to any commercial ship and provide general advice about underwater noise reduction to ship designers, builders and operators. The next stage is for ship operators and builders to follow these guidelines and implement measures to reduce noise. In Europe, the Marine Strategy Framework Directive (MSFD) was adopted with the overall objective of achieving or maintaining Good Environmental Status (GES) in EU waters by It includes two indicators ( and ) on introduced energy, including underwater noise, and EU member states must ensure that levels do not adversely affect the marine environment. However, underwater noise in European waters is yet to be satisfactorily addressed. Therefore, the Directive requires clear measures to reduce the impacts of anthropogenic noise on the marine environment and these can be achieved by setting targets. Member States should develop a programme of measures to address this in a timely manner. Continuing these operational practices will mean continued environmental benefits, especially for noise-sensitive marine life. Identifying the noisiest ships When it comes to noise, not all ships are equal, and it has been estimated that the noisiest 10% of vessels contribute most of the global underwater noise from shipping. Noisy ships are often operating inefficiently. Technologies to improve efficiency that can be applied to existing ships should also reduce noise. In 2009, the IMO called upon member governments and the industry to review their fleets in order to identify the noisiest ships; once the noisiest vessels have been identified they should then be prioritised for modification or replacement. New ship design and ship selection Advances in ship design have greatly improved fuel efficiency for new ships. The same computation methods should also be applied to ensure that noise is minimised. Shipping companies ordering new vessels should require underwater noise to be minimised. When chartering vessels, shipping companies could also include low noise levels in their selection criteria. IFAW/Song of the Whale Slow steaming Slow steaming, the practice of deliberately slowing down the speed of a ship to 21 knots, has been in place in the shipping sector for several years now. This lowers fuel consumption which reduces operational costs, but also reduces emissions. For most ships, going slower also substantially reduces underwater noise and this is especially true with extra slow steaming at 18 knots. It has been estimated that the noisiest 10% of vessels contribute most of the global underwater noise from shipping.

5 How the shipping industry can assist Maintain extra slow (18 knots) steaming practices - this will reduce overall noise and ship strike risk at a global level. Consider fitting new propellers optimised for slower speeds. Follow IMO guidelines for reducing underwater noise and apply noise reducing technologies to both existing ships and new builds. Help to identify the noisiest vessels by providing ship source characteristic data so that these vessels can be prioritised for noise reduction. M. Snyderman/Digital Stock/Corbis Case Study Vancouver EcoAction Since 2007, the Port of Vancouver EcoAction programme has been offering discounted harbour due rates to ships that have implemented voluntary emission reduction measures and other environmental practices. From 2017, this industry-leading incentive programme includes a marine noise reduction incentive, with criteria for three quiet-vessel ship classifications and three propeller technologies shown to reduce underwater noise. The incentive aims to reduce the impacts of shipping noise on at-risk marine life around the Port of Vancouver and to help address the wider underwater noise pollution issue. Factsheet Ocean Noise Pollution

6 Blue whales once communicated across entire oceans Today the area over which they can hear each other has been reduced by 90% because of increased underwater noise levels. Much of the ocean noise can be attributed to poorly designed and maintained ship propellers Shipping has dramatically raised ambient noise levels throughout the world s oceans and in many areas appeared to double each decade between the 1960s and 2000 About IFAW IFAW IFAW s mission is to rescue and protect animals around the world. We rescue individuals, safeguard populations and preserve habitat. As part of IFAW s efforts to protect marine life from the impacts of ocean noise we educate the public on this global pollution problem, work within the IMO to provide expert advice on marine mammals and focus on governmental and industry change to decrease underwater noise pollution throughout the world s oceans. Further information info-uk@ifaw.org