Introduction and thinking suggestions for underwater radiation noise issues

From June to October 2021, 7 groups of whale whale stranded occurred in the Fujian and Zhejiang coasts in my country, involving 47 animals including melon whales, rough teeth dolphins, bottle-nose dolphins and Belly whales. The Institute of Aquatic Biology of the Chinese Academy of Sciences conducted investigations on the incident. The results showed that underwater radiation noise caused whale hearing damage to cause whale hearing damage is one of the important reasons for such incidents.

1. The main source of underwater radiation noise

The underwater radiation noise of the ship refers to the noise generated and spread to the water in the water of the machinery and the pushing device, which is the main source of human underwater noise. In recent years, as the number of ships has been increasing and the main scale has increased, the problem of underwater radiation noise caused by the ship has become more serious. According to relevant surveys, the scope of small shipping levels is 150-180DB, and the scope of large-scale shipping levels is in the range of acoustic voltage levels in the range of shipping. 180-200db.

Figure 1 Drawing of underwater noise

According to the sound mechanism of underwater radiation noise, the underwater radiation noise of the ship is divided into propeller noise, structural noise, and fluid noise. Among them, propeller noise is the main source of underwater radiation noise. The propeller noise is divided into non -air bubble noise and empty bubble noise. Before the propeller speed is low, the noise is mainly caused by the rotation noise and vortex noise caused by the carrier load of the paddle. The soaking around the slurry is constantly generated and disappeared, and the instantly formed an empty bubble noise, and it becomes the main component of the propeller noise. Structural noise is noise or noise generated by machine -rearring equipment such as ship hosts, generators, air compressors, pumps, and other mechanical circular equipment. The fluid noise mainly contains noise caused by waves of waves and fluids acting on hull or hull attachments.

2. The impact of underwater radiation noise on marine animals

Unlike the sensory such as visual, hearing, and smell to perceive the surrounding world with the sensory such as vision, hearing, and smell. The main way of perception of marine animals is sound. Therefore, the communication of marine animals will be covered to reduce the communication distance. At the same time, noise will also affect the navigation, migration, avoiding enemy damage, and gathering of the marine animals. High level noise will even cause damage to marine animal hearing system damage. Or the death of marine animals.

Figure 2 Sound audio of ships and marine animals

During the Jiajing period of the Ming Dynasty, fishermen in Chaoshan area in Guangdong invented the fishing method of catching big yellow croakers: knocking on the operation. Use dozens of boats to surround the big yellow croaker group and pass the sound of the bamboo sheet into the water, causing the ears and stones of the rockfish and other stone croakers to resonate, and the yellow croaker shakes and floats the water surface for fishing. In the 1950s and 1960s, knocking operations were promoted to Jiangsu and Zhejiang as an advanced fishing method. In just two decades, the resource of the East China Sea Rhilistor's resource decline was almost extinct. It demonstrates the huge impact of underwater noise on marine animals from the side.

Third, the current situation of underwater radiation noise measurement

The measurement of underwater radiation noise measurement is the basic technology to study the underwater radiation noise of the ship. Radiation noise measurement standards are specified in the content of underwater radiation noise measurement equipment, measurement procedures, and data processing of the ship. At present, my country is relatively leading in the measurement of underwater radiation noise in ships. The Research Center (CSSRC) of the Chinese Academy of Shipping Science and Technology (CSSRC) has deeply participated in the formulation of ISO -related standards and completed the transformation of domestic standards.

In order to cope with the needs of the shipping industry for the technical standards of underwater radiation noise in the ship, the Chinese Class (CCS), the American Class (ABS), the Norwegian Class (DNV), the French Class (BV), and the British Laboles Shipping Club (LR), Italian Class (RINA), Korean Class (KR) and other ship -level agencies have also incorporated underwater radiation noise measurement technology into the standard system, and The ship is awarded the corresponding additional logo.

Figure 3 The basis for measurement of underwater radiation noise measurement

Although there are many current underwater radiation noise measurement, the standards and the specifications of the ship -level social social specifications are not uniform in measurement of environmental conditions, water hearing equipment, minimum distance, and data processing. As a result, it is not comparable, and it is impossible to intuitively compare the advantages and disadvantages of underwater radiation noise properties between different ships.

Fourth, the control measures for underwater radiation noise control measures

The underwater radiation noise control involves the entire life cycle of the ship. From the perspective of reducing the impact of marine animals, according to the three types of propellery noise, structural noise, and fluid noise Summary is shown in Table 1.

Although measures can be reducing the impact of underwater radiation noise on marine animals through measures such as speed reduction navigation, adjustment of vertical dumping, and optimizing the voyage plan, from the perspective of economics and effectiveness The design phase, especially the basic design stage, should be considered in the basic design stage. At the same time, factors such as the energy efficiency and ship safety of the ship should be coordinated. The control of the entire process of the ship -type line, the promotion of the system, the structural design, the selection of the equipment, the formation of the attachment, and the construction process will be reduced. The purpose of underwater noise.

5. IMO underwater radiation noise issues progress progress

The International Maritime Organization (IMO) pays attention to the 57th meeting of the Water Environmental Protection Council (MEPC) of the 2008 Maritime Environmental Protection Commission (MEPC). Essence Subsequently, the 58th meeting of MEPC established a communication group with the United States as a coordinator to formulate non -mandatory technical guidance on ship noise reduction technology and navigation and operation practice. In 2014, the 66th meeting of MEPC reviewed and passed the "Reducist to reduce the underwater noise of commercial shipping to reduce the negative impact on marine animals" and officially released it with MEPC.1/CIRC.833. In 2021, the 76th meeting of MEPC agreed to review and revise the 2014 version of the 2014 version of the 2014 version of the 2014 version of the "A Guide to reduce the negative impact of commercial shipping underwater noise" in the 2014 version. 2023. In 2022, the SDC8 Conference established a communication group that was coordinated by Canada to coordinate people. It was responsible for reviewing and revising the specific work of the old version of the guidance. At present, this part is underway.

6. Thinking suggestions

At present, my country takes marine powers and transportation power as the national strategy. At the same time, it attaches great importance to the construction of marine ecological civilization, strengthens the prevention and control of marine pollution, and protects marine life diversity. The new version of the guidance will inevitably lead to an increase in ship design, construction and operating costs. China must take this as an opportunity to meet the challenges and change the "桎梏" of China's shipping development as an "opportunity" to overtake other shipping powers.

The first is to increase the research and development of ship noise reduction technology. The underwater radiation noise is closely related to the energy effect of the ship. It is necessary to systematically study effective control measures for the design, construction and operation of the ship's design, construction and operation. New technology uses new ship type development, encouraging existing vessels to adopt measures such as increasing tail current adjustment devices and optimized voyage plans to continuously reduce the level of underwater radiation noise levels.

The second is to improve the rules of underwater radiation noise. We must adhere to the principles of overall planning, source prevention, control, classification management, and damage responsibility, explore the feasibility and necessity of the requirements of the ship's underwater radiation noise measurement and limit, and give full play to the feasibility and necessity of the ship's technical regulations and systems. The guidance, standardization, leading and guaranteeing role in the healthy and orderly development of the shipping industry.

The third is to strengthen international cooperation and exchanges in related topics. Compared with European and American countries, my country starts late in the research of underwater radiation noise issues in shipwrecks. We must master the relevant cutting -edge dynamics, closely track the progress of IMO issues, and in -depth participation guidelines in time to ensure the legitimate rights and interests of my country's shipping industry.

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