- Underwater radiated noise (URN) is a growing concern in the world’s oceans and can cause significant harm to marine life, particularly marine mammals.
- Managing URN is essential for marine conservation and sustainable ocean use.
- Marine spatial planning (MSP) is a holistic and integrated approach to ocean management that considers the spatial and temporal distribution of human activities and their impacts on the marine environment.
- Incorporating URN management into MSP can ensure the sustainable and responsible use of our oceans while preserving their biodiversity and ecosystem services.
- URN can have significant negative impacts on marine life, including hearing loss, stress, displacement, and even death in marine mammals, and can interfere with the behavior and physiology of other marine organisms.
- Managing URN in a way that is sustainable and responsible is crucial to minimizing its negative impacts on the marine environment and its inhabitants.
Introduction
Underwater Radiated Noise (URN) is a significant and growing concern in the world’s oceans. URN is generated by human activities such as shipping, oil and gas exploration, and military operations, and has the potential to cause significant harm to marine life, particularly marine mammals. Studies have shown that exposure to high levels of URN can lead to physiological and behavioral changes in marine mammals, including hearing loss, stress, displacement, and even death. As a result, managing URN has become an important issue for marine conservation and sustainable ocean use.
One approach to managing URN in the marine environment is through marine spatial planning (MSP). MSP is a holistic and integrated approach to ocean management that considers the spatial and temporal distribution of human activities and their impacts on the marine environment.
Importance of Managing Underwater Radiated Noise
URN can have significant negative impacts on marine life, particularly marine mammals. Marine mammals rely heavily on sound for communication, navigation, and foraging, and exposure to high levels of URN can interfere with these critical activities. Studies have shown that exposure to high levels of URN can lead to hearing loss, stress, displacement, and even death in marine mammals. For example, naval sonar has been linked to mass strandings of marine mammals, such as whales and dolphins, in several parts of the world. Shipping noise has also been shown to interfere with the communication and foraging of some marine mammal species, such as humpback whales.
In addition to its impact on marine mammals, URN can also affect other marine organisms and ecosystem processes. For example, URN can interfere with the behavior and physiology of fish, such as their feeding, reproduction, and migration. URN can also affect the acoustic communication and orientation of invertebrates, such as crustaceans and cephalopods. Furthermore, URN can alter the physical and chemical properties of the marine environment, such as the distribution and concentration of dissolved gases, and the sedimentation and erosion rates.
Given the potential negative impacts of URN on the marine environment and its inhabitants, it is essential to manage URN in a way that is sustainable and responsible.
Benefits of Incorporating URN Management into MSP
MSP can provide a useful tool for managing URN in the marine environment. By incorporating URN considerations into spatial plans and management strategies, MSP can bring several benefits, including:
First, MSP can provide a holistic and integrated approach to URN management. MSP can consider the spatial and temporal distribution of human activities that generate URN, such as shipping lanes, oil and gas exploration sites, and military training areas, and their potential impacts on the marine environment and its inhabitants. MSP can also consider the cumulative and synergistic effects of multiple human activities on URN and the marine environment.
Second, MSP can improve the effectiveness and efficiency of URN management. MSP can identify areas that are most sensitive to URN and prioritize them for protection or mitigation measures. MSP can also identify gaps and overlaps in URN management and coordinate efforts among different agencies and stakeholders. MSP can also provide a framework for monitoring and evaluating the effectiveness of URN management measures and adjusting them as necessary.
Third, MSP can increase the legitimacy and acceptance of URN management measures by engaging stakeholders and building consensus. MSP can provide a forum for open and transparent communication between stakeholders, where they can express their views and participate in the decision-making process. MSP can also build trust and understanding between stakeholders by providing them with accurate and up-to-date information on URN and its impacts on the marine environment. MSP can also involve stakeholders in the design, implementation, and evaluation of URN management measures, which can increase their sense of ownership and responsibility.
Fourth, MSP can promote innovation and collaboration in URN management. MSP can encourage the development and implementation of new and innovative technologies and approaches for reducing URN, such as ship design and retrofitting, noise-reducing coatings, and alternative propulsion systems. MSP can also foster collaboration among different sectors and disciplines, such as science, industry, and government, to share knowledge, resources, and expertise.
Fifth, MSP can contribute to the sustainable and responsible use of the marine environment. By managing URN and its impacts on the marine environment, MSP can ensure the long-term viability of marine ecosystems and their biodiversity. MSP can also support the sustainable and responsible use of marine resources, such as fisheries, tourism, and renewable energy, by minimizing their impacts on URN and the marine environment.
Examples of MSP for URN Management
Several countries and regions around the world have already incorporated URN management into their MSP processes. For example, in the United States, the National Oceanic and Atmospheric Administration (NOAA) has developed a strategic plan for managing URN in the Atlantic Ocean. The plan includes measures such as developing guidance for reducing URN from ships, promoting the use of alternative propulsion systems, and identifying and protecting critical marine mammal habitats.
In Europe, the European Marine Strategy Framework Directive (MSFD) includes a requirement to manage underwater noise as a pressure on the marine environment. The MSFD requires member states to monitor and assess the levels and impacts of URN and to develop and implement measures to reduce URN where necessary.
In Australia, the Commonwealth Marine Reserves Review included consideration of URN in the design of marine protected areas (MPAs). The review identified areas that were most sensitive to URN and prioritized them for protection measures, such as limiting shipping and acoustic surveys.
Emerging Ideas In URN
There has been a growing interest in developing new technologies to reduce URN from various human activities in the oceans. One of the most promising technologies is the use of low-noise ship designs, which can reduce the amount of noise that is emitted by vessels. For example, the use of podded propulsion systems, which are mounted outside the hull and use electric motors to turn propellers, can reduce underwater noise by up to 20 decibels compared to traditional shaft-driven propellers. Other technologies include noise-reducing coatings, which can be applied to the hulls of ships to reduce the noise that is generated by their movement through the water.
Another technology that is gaining popularity is the use of alternative propulsion systems, such as electric or hybrid propulsion systems, which can reduce the amount of noise and emissions that are produced by ships. For example, some ferries and small vessels are now powered by electric motors, which produce little or no noise and emissions. Hybrid propulsion systems, which combine electric and diesel engines, can also reduce noise and emissions by allowing ships to operate in electric mode in sensitive areas, such as near marine mammal habitats.
Sonar surveys, which are used to map the seafloor and to locate fish and other marine resources, are also a significant source of URN. New technologies, such as synthetic aperture sonar (SAS), can reduce the amount of noise that is generated by sonar surveys. SAS uses advanced algorithms to process the sonar data, which can improve the resolution and accuracy of the images while reducing the noise that is emitted by the sonar.
Finally, there are also efforts to reduce the amount of noise that is generated by offshore renewable energy projects, such as wind farms and tidal turbines. For example, some wind turbines are now equipped with noise-reducing blades, which can reduce the amount of noise that is generated by their rotation. Other technologies, such as subsea transformers and converters, can also reduce the amount of noise that is generated by offshore renewable energy projects.
Concluding remarks
URN is a significant and growing concern in the world’s oceans, with the potential to cause significant harm to marine life and ecosystem processes. MSP provides a useful tool for managing URN in a way that is sustainable and responsible. By incorporating URN considerations into spatial plans and management strategies, MSP can provide a holistic and integrated approach to URN management, improve the effectiveness and efficiency of URN management, increase the legitimacy and acceptance of URN management measures, promote innovation and collaboration, and contribute to the sustainable and responsible use of the marine environment.
As the demand for ocean resources continues to grow, we must manage URN in a way that balances the needs of human activities with the needs of the marine environment and its inhabitants. By incorporating URN management into MSP, we can ensure that our oceans are used in a way that is both productive and sustainable while preserving their biodiversity and ecosystem services for future generations.
Sanskar Soni
About Author
Sanskar Soni works as a Research Fellow at MRC and has a keen interest to discover more about the maritime domain. He is an enthusiastic chemical engineering student at the Indian Institute of Technology (IIT) Delhi, who has a strong passion for machine learning. He has a proven track record of working in the field of website development and has also gained significant experience in research in machine learning and computational biology. He has been selected for an internship at Piramal Pharma Limited in 2023. Besides, Sanskar is an active member of the Student Affairs Council at IIT Delhi.