The SOUNDS project: towards effective mitigation of underwater noise from shipping in Europe (original) (raw)
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Management Measures to Reduce Continuous Underwater Noise from Shipping
Swedish Institute for the Marine Environment Report No. 2023:3, 2023
Underwater radiated noise (URN) from commercial ships is a significant source of elevated noise levels in the oceans and can have a negative impact on marine wildlife. Noise from commercial shipping places additional stress on the oceans, but is one of the least studied environmental pollutants, and there is an urgent need to reduce the aggregate stress levels. Until recently, reduction of underwater noise has not been prioritised by ship designers, shipowners, or crews. Even within the field of marine management, noise has received limited interest. However, the International Maritime organization (IMO) has adopted global guidelines on URN reduction, which are currently being updated. Within the EU, the Marine Strategy Framework Directive (MSFD 2008/56/EC) Descriptor 11 criteria 11.2, now provides a framework for marine administrators to manage noise by establishing threshold values. Marine management focuses on the total noise load on the marine environment. Management entails several considerations before recommendations can be made. As a first step, interdisciplinary teams need to assess the aggregated noise levels and determine acceptable thresholds based on the local ecosystem, then assess which existing mandates and management tools can be used, and finally assess how effective these mandates have been in improving the environment. These activities must also be managed in a way that is acceptable to various relevant stakeholders, who would need to follow the decisions. The URN from a ship can be affected by the vessel’s design, either during its construction or during upgrades, and balances a trade-off against fuel efficiency. However, the URN can also depend on how the ship is operated. Regulating ship speed is one potential management tool, and its effectiveness needs to be assessed. Other management measures include how shipping lanes are drawn, areas to avoid, financial support, information, etc. This report focuses on possible policy measures that the Swedish authorities could adopt to lower URN by regulating the speed of ships. The report presents an interdisciplinary analysis, using a case study of an area in the southern Kattegat that covered several maritime zones, different national jurisdictions, intensive traffic, and high natural values. An important part of the work was to assess whether existing source models for ship noise could be used for the type of ships that are common in waters around Sweden. In this study, the JOMOPANS-ECHO (J-E) model was used. The J-E model was validated by comparing measurement data from a hydrophone station at Vinga on the Swedish coast that collected data from ships (254 passages) that used the port of Gothenburg. The analysis showed some deviation between the J-E model and measurement data, which could be due to differences in the length and speed of ships in waters around Sweden compared to the ships used in the development of the J-E model. However, this was likely to have negligible impact on the outcome of the case study. Analyses of ship traffic in 2021 showed that 4,511 unique vessels visited the study area at least once. Most ships followed the main routes, but no part of the study area was completely free from ship traffic. About 68% of the ships visited the study area for 1-4 days, while about 32% visited the area more regularly. The most common ship types were General Cargo Ships, Dry Bulk Ships, and Tankers. The ships that on average travelled at highest speeds were RoPax Ships, RoRo Ships, Vehicle Carriers, and Container Ships. The ships were registered in 64 countries. About two percent of the ships were registered in Sweden and about four percent in Denmark. Legal analysis showed that Sweden has the right and the responsibility to take measures to reduce underwater noise from ships to the extent that the noise can be deemed to pollute the marine environment. However, this mainly applies to Sweden’s territorial seas, which cover roughly half the area being studied for this report. In the portion that constitutes Danish territorial sea, Denmark has comparable opportunities for managing URN. In areas that are Swedish or Danish exclusive economic zones (EEZs), the ability to introduce mandatory speed limits is significantly limited. There, the most realistic option would be to request the IMO to establish speed limits, or alternatively to issue a recommendation to navigate at lower speeds, although such guidance could not be enforced on ships that do not voluntarily reduce their speed. It was estimated that lowering the ships' speeds to a hypothetical limit of 11 kn would reduce the average URN levels by 4.4 ± 2 dB, as registered by local receivers in the study area. This speed limit would affect approximately 44% of the ships in the area. A maximum speed of 13 kn would instead reduce the level by 1.9 ± 0.5 dB and would affect 11% of the ships on average. The reduction in noise levels may temporarily be much higher in the immediate vicinity of individual fast ships, and there might be a high degree of variation between different ships. The study and report make it clear that it is a complex task to assess the feasibility and benefit of introducing a specific marine management tool, in this case an enforceable local speed limit. But it is also clear that there are reliable methods to make the preliminary assessments, and that it requires interdisciplinary analyses and competence.
European project for achieving quieter oceans by shipping noise footprint reduction
The Journal of the Acoustical Society of America, 2014
There is a growing consensus among the scientific community for the need to mitigate underwater noise footprint due to shipping, in order to prevent negative consequences to marine life. In that context, AQUO project started in October 2012, in the scope of the FP7 European Research Framework, for three years duration. The final goal is to provide policy makers with practical guidelines and solutions, acceptable by shipyards and ship owners, in order to mitigate underwater noise due to noise radiation from ships. First, a general presentation of the project will be given. A key element is the development of a "Shipping noise footprint assessment tool" providing noise maps derived from ship traffic information. Several other studies are undergoing, covering ship underwater radiated noise, propeller noise (including cavitation), and bio-acoustic experiments. The AQUO project team is composed of ship industry, specialized companies, a classification society, research centres and academics, allowing addressing the complexity of the topic. In a second part, a definition of the noise footprint for the problem considered here is proposed, and the methodology followed to build the guidelines is presented.
The development of a policy framework to mitigate underwater noise pollution from commercial vessels
Marine Policy, 2020
Oceans are under severe pressure due to immense anthropogenic activities and related pollution and impacts. Although shipping is the most fuel efficient mode of transportation and, accounting for 80% of transportation of cargo by volume while playing an important role in global trade, it has negative environmental and socioeconomic externalities and threatens sustainable development. It is predicted that World seaborne trade will grow by a factor of 2.5% from 2020 to 2040. It is necessary to take appropriate actions to control and mitigate the negative impacts of international shipping. One of the newly emerging environmental issues resulting from anthropogenic activities is Under Water Noise (UWN). UWN has adverse impacts on the marine environment within and beyond national jurisdiction, and it is becoming a significant threat to both underwater life and socioeconomic status. While most of the negative externalities from international shipping have been regulated, UWN pollution has not been regulated appropriately. Although policymakers in some jurisdictions have commitment for the mitigation of this pollution, there is no international legally binding instrument to control, mitigate, and monitor. This legal gap makes stakeholders reluctant to take appropriate action to address the issue. This paper explores the policy context of underwater noise mitigation in commercial shipping to support the development of effective and efficient underwater noise management framework. The paper concludes that the multi-interdisciplinary command and control approach with consideration of multi-dimensional incentive regimes must be considered for any further action and policy decision making regarding UWN pollution from commercial vessels.
IEEE Journal of Oceanic Engineering, 2017
There is increasing concern within the scientific community about the underwater noise due to anthropogenic activity and its impact on marine life, with negative consequences on biodiversity and sea resources. In that context, the European Marine Strategy Framework Directive stated in 2008 that the anthropogenic noise due to shipping was to be mitigated. To address this issue, the European Union (EU) project "Achieve QUieter Oceans by shipping noise footprint reduction" (AQUO) (www.aquo.eu) started in October 2012 with a duration of four years. The project brought together experts from shipbuilding, underwater acoustics, and bioacoustics, with a multidisciplinary approach. In this paper, after giving a brief overview of the project structure, the methodology proposed by the AQUO project to set guidelines for controlling the underwater noise from commercial shipping is presented in more detail. Such a methodology is aimed at identifying the most promising strategies for the mitigation of the impact of shipping noise on marine fauna. Different technical as well as operational solutions are evaluated by taking into account the impact on marine life, the feasibility in terms of ship design, and the cost effectiveness, also considering fuel efficiency. While technical solutions are usually more effective at the design stage both in terms of costs and performance, operational solutions can potentially be adopted without any modification to the existing fleet. Furthermore, operational prescriptions can be set by national/local authorities who cannot directly intervene on ship configurations. The different solutions have been evaluated by means of numerical modeling carried out by using a Noise Footprint Assessment Model derived from the Quonops tool.
Marine Pollution Bulletin, 2022
This paper aims to find mechanisms to align commercial interests with underwater noise reductions from commercial shipping. Through a survey and a series of interviews with representative stakeholders, we find that while acknowledging the wide variations in ports' specificities, port actions could support the reduction in underwater noise emissions from commercial shipping through changes in hull, propeller and engine design, and through operational measures associated with reduced speed, change of route and travel in convoy. Though the impact of underwater noise emissions on marine fauna is increasingly shown to be serious and widespread , there is uncertainty in the mechanisms, the contexts, and the levels which should lead to action, requiring precautionary management. Vessels owners are already dealing with significant investment and operating costs to comply with fuel, ballast water, NOx and CO2 requirements. To be successful, underwater noise programs should align with these factors. Based on a multiple criteria decision making (MCDM) approach, we find a set of compromise solutions for a wide range of stakeholders. Ports could propose actions such as discounted port fees and reduced ship waiting times at ports, both depending on underwater noise performance. Cooperation between ports to scale up actions through environmental indexes and classification societies' notations, and integration with other ports' actions could help support this. However, few vessels know their underwater noise baseline as there are very few hydrophone stations, and measurement methodologies are not standardized. Costs increase and availability decreases dramatically if the vessel buyer wants to improve the noise profile. Local demands regarding airborne noise close to airports boosted global pressure on the aviation industry to adopt existing quieting technology. This experience of the aviation noise control could inform the underwater noise process.
Normative framework for ship noise: Present situation and future trends
2012
The paper addresses the present regulatory framework regarding ship noise emissions both towards the internal spaces onboard and the external environment (in air and in water). A different level of development has been reached in the various areas for the definition of the needs for the noise control and for their implementation in a normative framework. This is due in part to the different point in time in which the different aspects were recognised to be relevant and therefore studied, assessed and regulated. The analysis of existing regulations is the basis for considering the present situation, on-going developments and possible future trends as regards the evaluation of ship noise impact on the various types of environment. The situation of the requirements developed for the maritime field appears to be in line with other fields of engineering as regards the definition of noise limits for the working environment, while the definition of comfort of living on board seems to be somehow lacking behind other fields, with possibility of taking advantage of their experience. Well established assessment procedures for external radiation in air appear to be not yet available and in this case a need for specific developments arises. Finally, for underwater noise emissions, there is availability of relatively well developed requirements, that however are not adequately correlated to the quantification of the effects of the noise emissions on the marine fauna.
Relationship between ship type and underwater noise emissions
Concerns that shipping noise could affect marine mammals were raised as early as the 1970s. This was based on the observation that there was a considerable band overlap between the spectra of frequencies used by large Baleen Whales and the major components of noise from the propellers of commercial vessels. This is a very serious threat to the species, since they rely almost entirely on sound waves for communication and hunting. Baleen Whales aren’t the only species affected by shipping noise either, the noise has been observed to cause avoidance behaviours and stress in many other species of fish, in addition to interfering with communication. Out of all the frequencies, elevated noise levels that lie in the 10-300 Hz range have the ability to mask biologically generated sounds. With the increase in global shipping over the last few decades, oceanic ambient noise levels have been rising correspondingly. The NOAA has found evidence that underwater sound has been doubling every 10 years with most of the sound being anthropogenic. These increases amount to 20 dB from the pre-industrial era to the modern age. In the vicinity of major shipping routes, increases in noise can be much larger. Propeller cavitation seems to be the predominant noise source on-board maritime vessels and propeller singing can potentially cause emissions of high-pitched noise. Improved propeller design e.g. anti-singing trailing edge, and efficient wake flow may serve to reduce acoustic emissions. For merchant vessels, it is necessary to accept a certain amount of cavitation in the propeller, at present, because designs that eliminate cavitation reduce efficiency drastically. It is probable that, statistically, one-tenth of the noisiest ships generate a major portion of the net impactful noise undersea. In recent times, international policy making bodies have begun taking environmental concerns very seriously, and although there is no internationally accepted standardization document that guides shipbuilders on crafting less noisy vessels yet, there are two important standards that aid underwater noise measurement.
Normative framework for ship noise: Present and situation and future trends
Noise Control Engineering Journal, 2012
The paper addresses the present regulatory framework regarding ship noise 5 emissions both towards the internal spaces onboard and the external environ-6 ment (in air and in water). A different level of development has been reached 7 in the various areas for the definition of the needs for the noise control and 8 for their implementation in a normative framework. This is due in part to the 9 different point in time in which the different aspects were recognised to be 10 relevant and therefore studied, assessed and regulated. The analysis of existing 11 regulations is the basis for considering the present situation, on-going develop-12 ments and possible future trends as regards the evaluation of ship noise impact 13 on the various types of environment. The situation of the requirements developed 14 for the maritime field appears to be in line with other fields of engineering as 15 regards the definition of noise limits for the working environment, while the 16 definition of comfort of living on board seems to be somehow lacking behind 17 other fields, with possibility of taking advantage of their experience. Well estab-18 lished assessment procedures for external radiation in air appear to be not yet 19 available and in this case a need for specific developments arises. Finally, 20 for underwater noise emissions, there is availability of relatively well developed 21 requirements, that however are not adequately correlated to the quantification 22 42 harbours, while underwater noise affects the ocean envi-43 ronment and the marine fauna. Recent studies suggest 44 that a large percentage of people living in urban areas 45 close to harbours R1 1 and a number of marine species, at 46 different evolutionary levels R2 2 , suffer from ship noise 47 emissions. Underwater noise emissions are clearly typi-48 cal of ships and pose specific questions, given the differ-49 ent transmission medium and the different kind of 50 receivers, but the other aspects of the assessment of 51 the ship noise impact, too, have peculiar characteristics 52 in comparison with other vehicles, related to the dimen-53 sions and complexity of the ship structure, to the variety 54 of sources and operational conditions on board, to the 55 relative positions of sources and people affected and to 56 the generally higher time duration of exposures (for 57 internal noise). 58
Reducing Underwater Noise from Large Commercial Ships: Current Status and Future Directions
Who should read this paper? If your employment relates to a marine industry, this paper might brief you on the contents of your next staff meeting. If you own, operate, or work on a vessel, and are subject to IMO legislation, this paper certainly concerns your interests. If you are casually interested in the ocean, or feel a concern for communities of cetaceans and other marine fauna, go ahead and sate your curiosity about ocean noise. Why is it important? You may have heard the clamour about anthropogenic ocean noise. Citing new legislation as adding pressure to a growing consensus against ocean noise, this paper is a clear interpretation of the facts and offers recommendations which suit them. Given the historically diverse nature of the marine community and the consequent challenges to its regulation, the field of ocean noise regulation appears a decentralized, overwhelmed, unmanageable branch. This research ignores the noise and picks up the signal; that is, it focuses on reasonable priorities to create tangible results with detailed explanations for how identifying problem vessels can be done efficiently, along with solutions and how to implement them. (Spoiler alert: check your propeller.) This review and, in essence, proposal features technologies that are already commercially available. The authors emphasize the potential for reducing noise levels alongside improvements in fuel efficiency, offering a benefit to mariners for pursuing quieting measures. At a time when there is a lot of racket over ocean noise, this paper sounds calm and rather relaxing.