A test system and test method for the impact of underwater noise on fish growth

Abstract

The present invention provides a test system and test method for the effect of underwater noise on fish growth. The underwater noise N1 recorded at the waterway site is input into a computer command terminal to simulate the underwater noise characteristics during the day, night, and flood, dry, and normal water periods: the size of the pool is adjustable, and slots are provided on the left and right edges of the entire pool for fixing partitions. The water circulation system purifies and filters the water back into the pool. A temperature regulating blanket is laid at the bottom of the pool to provide insulation and temperature control. A layer of sound-insulating and dimming glass is laid outside the pool. The present test system and method can provide a suitable living environment for the test fish, solve the problems of water temperature control, oxygen control, and water quality control in indoor tests on the effect of fish growth, simulate underwater noise under different time conditions, provide methodological support for the study of the effect of underwater noise on fish growth, and provide reference value for other subsequent test systems and methods.

Description

Technical Field

[0001] The present invention relates to the technical field of ecological environmental impact of underwater noise, and in particular provides a test system and a test method for the impact of underwater noise on fish growth. Background Art

[0002] With the development of the shipping industry, port development and ship traffic are becoming increasingly busy. The adverse impacts of underwater noise generated by shipping and waterway construction on fish, as well as mitigation strategies, have attracted attention. Underwater noise characteristics vary depending on time and location, the number of ships in the water, their speed, tonnage, and the topography of the waterway, and therefore their impact on fish. For example, the sound of a single ship has its own unique noise characteristics, which can be detected from a distance of several kilometers. Ship noise is highest near ports and waterways, and as the number of ships on the high seas increases, ship noise levels are increasing. Ships at sea, combined with construction and industrial activities on land, generate even more significant noise, including pile driving, dredging, drilling, the use of explosives, and oil and gas production facilities. Fish have a limit to their tolerance for ship noise; exceeding this limit can cause irreparable harm, such as hearing loss, adversely affecting their growth and development, and disrupting their vital activities, such as feeding and spawning.

[0003] The effects of ship noise on fish growth cannot be generalized; they vary within and between species. The impacts are also influenced by other environmental factors, such as light, temperature, water quality, and dissolved oxygen, as well as the fish's physiological state, age, and body size. Therefore, studying the effects of underwater noise on fish growth is a long-term undertaking, requiring extensive information to assess and predict any negative impacts. Field experiments can recreate various influencing factors under realistic conditions, but they present numerous interfering factors and uncertainties. Obtaining accurate experimental data under various variables requires a long time to overcome these interfering factors, consuming both human and material resources. Therefore, indoor experimental studies are becoming more popular. Indoor experiments can eliminate uncontrollable external factors, identify key factors, and mitigate more minor ones. Therefore, it is necessary to establish a scientific, environmentally friendly, and convenient fish testing system and method to quantitatively assess the effects of underwater noise on fish growth and provide technical support for the implementation of appropriate fish impact mitigation strategies in shipbuilding, navigation, and water transport engineering design and construction.

[0004] At present, many studies have been conducted on the impact of underwater noise on fish growth, and a large number of experiments have been carried out. However, there are too many interference factors in the experimental process, the experimental results lack representativeness, and a more scientific and convenient experimental system and experimental method have not been found. For example: (1) In the experiment, sound insulation cotton B3 was used to isolate the external environmental noise, but the noise interference of the circulating pump C9, oxygenation pump and other equipment during the experiment was not isolated. (2) In the experiment, temperature control was mentioned and heating rods were used to maintain the temperature, but too fast a change in water temperature would affect the normal life activities of fish, such as causing fish to breathe faster, increase oxygen consumption, and be prone to hypoxia. (3) The experiment only focused on the size change of the initial experimental device, and did not mention the reasonable change of the living space of the fish. (4) When more variable gradients need to be set, multiple sets of experimental systems need to be added, and the experimental equipment is large and complex. (Lu Yuetong, [Study on the stress behavior response pattern and internal regulatory mechanism of zebrafish in water quality warning], Xi'an University of Technology, 2023; Xing Binbin, [Study on the auditory ability of fish], Shanghai Ocean University, 2019; Xiong Yuyu, Zhu Sihua, Zeng Kewei, et al., [Social learning of feeding behavior of juvenile mandarin fish], Sichuan Animal Science, 2010, 29(03):415-418; Shi Ni, Li Yingwen, Liu Zhihao, et al., [Effects of noise on fish], Journal of Chongqing Normal University (Natural Science Edition), 2017, 34(04):28-32; Yin Leiming, [Study on the behavioral response and mechanism of sound attraction of large yellow croaker], Shanghai Ocean University, 2018)

[0005] Designing indoor fish impact tests requires controlling variables while realistically recreating the interference of underwater noise. Simulating the real-time characteristics of noise is crucial. Second, other influencing factors, such as ambient noise, temperature, water quality, and living space, must be eliminated. For example, a suitable living space is a crucial factor influencing the fish test process, directly affecting their growth, health, survival rate, and functional gene expression. Numerous studies have shown that overstocking fish can impair the survival of certain species, leading to slower growth and increased growth dispersion. Summary of the Invention

[0006] The purpose of the present invention is to provide a test system and test method for the impact of underwater noise on fish growth, which can simulate the underwater noise characteristics under different conditions, reasonably adjust the living space of fish, block interference from other sound sources, recycle water, stabilize water temperature and adjust light.

[0007] The technical solutions of the present invention are as follows:

[0008] An underwater noise impact test system for fish growth mainly consists of five systems: noise variation system, size adjustment system, water circulation system, temperature control system and sound insulation and light adjustment system.

[0009] Noise variation system: It consists of a computer control terminal, power amplifier adjustment terminal and underwater speakers. The underwater noise N1 recorded at the waterway site is input into the computer control terminal to simulate the noise sound pressure level during the day and night, and the underwater noise cycle during flood, dry and normal water periods:

[0010] ① At night: Due to limited visibility, especially in urban waterways, and the interference of other lights, ships need to reduce their speed to ensure navigation safety. Therefore, the sound pressure level of the sound source will be reduced, and the noise N1 will be converted to a smaller tone N2;

[0011] ② During the day, the navigation channel has a wide view. Under the premise of safe navigation, the navigation speed will be relatively faster, so the sound pressure level of the sound source will increase, and the noise N1 will be converted to N3;

[0012] ③ Flood season: There is an increase in floating debris on the water, and navigation aids such as buoys are prone to displacement. The water level in the channel rises significantly, the flow rate increases, the flow velocity increases, the channel conditions change greatly, and even the channel shifts. It is necessary to control the speed and keep a sufficient distance between ships. Therefore, it is necessary to reduce the noise cycle and sound pressure level, which is the ship noise N4;

[0013] ④ Dry season: During the dry season, the water depth of the channel becomes shallower and the navigation conditions become worse, which can easily cause stranding and blocking of navigation, and increase the probability of collision between passing ships. To ensure navigation safety, the number of ships will be relatively reduced, and the reduction period is ship noise N5;

[0014] The amplifier control terminal adjusts the sound pressure level based on the sound source. A variety of sound pressure level gradients can be set to analyze the impact of various noise characteristics on fish. The speaker playback section is an underwater speaker placed under the pool to simulate underwater noise propagation. Its other end is directly connected to the amplifier control terminal.

[0015] Size adjustment system: The present invention can adjust the size of the pool at will, thereby adjusting the living space of the fish in a timely manner and allowing the fish to have a good living condition. The present invention sets slots along the left and right edges of the entire pool. Each slot can be used to place a 5cm thick partition. The partition can be moved back and forth to change the size of each pool and the distance of each pool relative to the underwater speaker. The width of the slot is 5cm and the height is 10cm, and the partition can be fixed at a vertical distance. Sound insulation cotton can be flexibly installed between the upper and lower groups of slots to further control the sound pressure level of each pool, set more sound pressure level gradients, and study the impact indicators of fish under different sound pressure level gradients. The sound pressure level can also be further adjusted in conjunction with the sound source. The number of slots n in each pool can be adjusted according to the total weight M of the fish. f calculate:

[0016] ρ f =M f / V

[0017]

[0018] Where: f is the fish stocking density, which is determined by the type of fish; M f is the total weight of the fish in the pool; V is the volume of water required in the pool; H and B are the water depth and width of the pool respectively; n is the number of slots required in each pool 1 (excluding sound insulation cotton).

[0019] Water circulation system: Mainly composed of water pipes, a water purification tank, and a water pump. The water purification tank is located directly in front of the pool and is connected to the pool via a water pipe. The water pipe is divided into a drain pipe and an inlet pipe. The drain pipe inlet is located at the bottom of the pool and is sealed with a cap. There are four drainage branches and a main drainage pipe. There is a drain valve at the outlet of the main drainage pipe. When the pool water needs to be changed, open the caps of each drainage branch and the drain valve of the main drainage pipe. The main drainage pipe leads to the water purification tank. Three filter screens (filter cotton, activated carbon, and biochemical balls) divide the water purification tank into four sections. Through physical filtration by the filter cotton, chemical filtration by the activated carbon, and biological filtration by the biochemical balls (glass rings), insoluble impurities, waste, and harmful water-soluble substances in the water are removed, and toxic substances produced by fish metabolism are converted into non-toxic substances. The pH value of the water quality can also be adjusted. In the fourth section of the water purification tank, a pump is installed to pump purified water into the tank. Near the pump is an inlet valve, and the inlet pipe runs from the top of the tank into the tank. An aerator is also installed in the fourth section of the water purification tank. When the dissolved oxygen falls below a certain value, the aerator automatically turns on. When the dissolved oxygen reaches an appropriate level, the pump valve opens to discharge the water into the tank.

[0020] Temperature Control System: This invention achieves temperature stability by laying a temperature-regulating blanket at the bottom of the pool. This blanket is evenly layered with a material with high thermal conductivity, such as aluminum, to quickly absorb and effectively transfer heat from the surrounding environment. In summer, when the upper water temperature is high, the blanket absorbs excess heat through the thermally conductive material. In winter, when the water temperature is lower, the blanket absorbs external heat and effectively transfers it to the pool, thereby providing insulation and temperature control.

[0021] Sound insulation and dimming system: The present invention lays a layer of sound insulation and dimming glass outside the pool to block environmental noise and prevent transient changes in external light from affecting the experimental fish. By using highly transparent sound insulation equipment, while ensuring that the underwater noise played by the underwater speaker is the only sound source variable in the experiment, it is convenient for the experimenter to observe and record the living conditions of the fish. To prevent light interference, such as the light intensity of the external environment, the light intensity when people walk, the light intensity caused by weather changes and other changes in light intensity, the sound insulation and dimming glass uses glass that can adjust the light and stabilize the light. Unlike general dimming glass, for experimental observation, the sound insulation and dimming glass does not block the outside world's sight, but stabilizes the light intensity. When powered on, the light passing through the glass is emphasized to a fixed value suitable for the survival of fish, to stabilize the light intensity passing through the sound insulation and dimming glass, thereby preventing sudden changes in the light intensity of the external environment from affecting the experimental fish, and to a certain extent, it also plays a role in stabilizing the water temperature.

[0022] A method for testing the effect of underwater noise on fish growth, using the aforementioned test system for the effect of underwater noise on fish growth, the method comprising the following steps:

[0023] The cycle period and sound pressure level of underwater noise were adjusted to simulate the noise characteristics during the day, night, and during flood, dry and normal water seasons. After controlling the water temperature, ensuring water quality, isolating environmental noise and stabilizing the light, noise was used as the only variable in the experiment. Different noise sound pressure level gradients and noise cycle periods were set to conduct multiple groups of experimental controls.

[0024] The beneficial effects of the present invention are as follows: in experiments on the effects of underwater noise on fish growth, the cycle and sound pressure level of underwater noise can be automatically adjusted to simulate noise characteristics during the day, night, and during flood, dry, and normal water periods. After controlling water temperature, ensuring water quality, isolating ambient noise, and stabilizing lighting, noise is used as the sole experimental variable. The device of the present invention can arbitrarily adjust the position of the partitions to select a suitable living space for the experimental fish, and adjust the distance from the sound source to adjust the noise level in each pool. By adding sound insulation cotton to the pool, different noise sound pressure level gradients are set, and multiple groups of experimental controls are conducted. The water circulation system provides living water conditions for the fish, recycles water resources, and protects the water environment. This experimental system and method can provide a suitable living environment for experimental fish, solve the problems of water temperature control, oxygen control, and water quality control in indoor experiments on the effects of fish growth, simulate underwater noise under different time conditions, provide methodological support for experimental studies on the effects of underwater noise on fish growth, and provide reference value for subsequent other experimental systems and methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1a This is one of the general layout diagrams of the device of the present invention;

[0026] Figure 1bThis is the second overall layout diagram of the device of the present invention;

[0027] Figure 2 It is the underwater noise propagation path diagram of the present invention;

[0028] Figure 3 It is a schematic diagram of the water pool B1 of the present invention;

[0029] Figure 4 Schematic diagram of water circulation system C of the present invention;

[0030] Figure 5 is a schematic diagram of the temperature regulation blanket of the present invention;

[0031] Figure 6 It is a schematic diagram of the sound insulation and dimming system of the present invention. DETAILED DESCRIPTION

[0032] In order to make the objects and advantages of the present invention more clear, the present invention is further described below with reference to the accompanying drawings; it should be understood that the specific examples described here are only used to explain the present invention and are not limited to the present invention.

[0033] The device of the present invention is mainly used for indoor experimental research on the effect of underwater noise on fish growth. The underwater noise collected in the waterway is used as the only variable, and the test is carried out in an environment with suitable temperature, dissolved oxygen content, stocking density and water quality. Figure 1a and Figure 1b It consists of 5 parts: noise change system A, size adjustment system B, water circulation system C, temperature control system D and sound insulation and dimming system E.

[0034] Noise Variation System A Figure 2 The frequency and sound pressure level of the ship noise are mainly set by the computer command end, the power amplifier adjustment end A1 adjusts the noise sound pressure level, and the underwater speaker A2 playback end broadcasts the noise to the pool B1. The computer command section mainly reads and analyzes the original noise data, obtains the sound wave vibration amplitude audio and sampling frequency fs of the noise in the m4a file, simulates the noise characteristics in the waterway, and simulates the changes in the noise sound pressure level when the number of ships is small by changing the noise vibration amplitude audio, such as in the waterway at night and during flood seasons. In this case, it is 0.5 times the original amplitude at night and 2 times the original amplitude during the day. By changing the interval time of each audio playback, the noise cycle period with different ship density is simulated. For example, in the flood season and the dry season, the ship density is smaller, so the interval between each audio loop playback is extended. In this case, the interval time is extended from 5s to 10s. The loop playback time depends on the season, day and night:

[0035] During the flood season from May to September, the loop playback interval is 10 seconds per play. During the long daytime hours and high ship density, the ship noise sound pressure level is higher between 6:00 AM and 8:00 PM, reaching twice the original sound wave amplitude. During the short nighttime hours, from 8:00 PM to 6:00 AM, when the ship density is low, the ship noise sound pressure level is lower, reaching 0.5 times the original sound wave amplitude.

[0036] December to February is the dry season, and the loop playback interval is 5 seconds per play. Daytime is short, and the ship noise sound pressure level is higher from 8:00 AM to 7:00 PM, at twice the original sound wave vibration amplitude. Nighttime is even shorter, from 7:00 PM to 8:00 AM, and the ship noise sound pressure level is set at 0.5 times the original sound wave vibration amplitude.

[0037] February to March and September to December are the normal water seasons, when there are differences in the sound pressure levels of ship noise played at night and during the day, as well as the time intervals of looped playback. They can be used as control groups. If the study is about the effect of the noise playback cycle on fish growth, the sound wave vibration amplitude will be set to be the same as that in the flood season or the dry season. If the study is about the effect of the noise sound pressure level on fish growth, the cycle period will be set to be the same as that in the flood season or the dry season.

[0038] Amplifier control terminal A1 directly adjusts the sound pressure level through the amplifier's volume control. During experiments, when qualitative analysis of the impact on fish is needed, it can be used as a temporary volume control device, such as observing changes in fish swimming, feeding, and spawning behavior as the sound pressure level changes. Amplifier control terminal A1 can also quickly block playback from underwater speaker A2. If dangerous conditions such as fish injury or death are detected during the experiment, sound transmission can be quickly blocked.

[0039] Size adjustment system B Figure 3 Set up in pool B1, at the start of the experiment, the appropriate stocking density needs to be set based on the fish species and weight. This requires pre-adjusting the dimensions of each pool B1. Suitable living spaces for the fish are created by adding partitions B4 between the slots B2 located at the left and right edges of pool B1. In experiments studying the impact of ship noise on fish growth and development, as fish weight, length, and width change, they need to be moved forward into the front slots B2 to maintain the same stocking density as at the start of the experiment.

[0040] Setting the appropriate sound pressure level (SPL) allows for optimal noise characteristics of the underwater speaker A2 by adjusting the computer control terminal and the amplifier control terminal A1. To quantitatively describe the impact of underwater noise on fish, a series of SPL gradients are required. Install sound insulation pads B3 on both sides of the bulkhead B4. Select pads with the same sound insulation performance. Each pad can be used to set a single SPL gradient. The pads B3 rest against the bulkhead B4, fitting between the upper and lower corresponding slots B2. If water pressure or flow rate is excessive, secure the pads B3 between the slots B2 and then secure them to the bulkhead B4 with thumbtacks. The pads B3 can be secured to the front and rear of the bulkhead B4. If the dimensions of the pool B1 are unaffected, secure the pads B3 away from the pool B1.

[0041] The test on the effect of noise on fish growth is a long-term test. During the experiment, water needs to be changed regularly. Figure 4 Realize water reuse. Figure 3 Water circulation system C is the energy storage system of the facility, responsible for timely replacement of the water in tank B1, purifying wastewater, and aerating the stored water. The main component of water circulation system C is the purification tank C4, which is divided into four sections by three filters. The first section directly contacts the main drain pipe, followed by three filter chambers, and the final section where the purified water is stored. This final section houses a pump C9 and an aerator C8. Water circulation system C is connected to tank B1 via a drain pipe C2 and an inlet pipe C11. Drain pipe C2 horizontally connects tank B1 and purification tank C4. A branch drain pipe leads to the bottom of tank B1, where it joins the main drain pipe and flows into the first section of purification tank C4. Inlet pipe C11, located in the fourth section of purification tank C4, connects to pump C9 and injects purified water from the top side of tank B1. Water circulation system C primarily involves two processes: drainage and intake.

[0042] (1) Drainage: To prevent pollutants from remaining in the corners where the partition B4 and the sound insulation cotton B3 contact the pool B1, the partition B4 and the sound insulation cotton B3 need to be removed. Open the cap C1 at the bottom of the pool B1, and then open the drain valve C3. The sewage is discharged into the clean water pool C4 through the drain pipe C2, and then passes through the filter cotton C5, activated carbon C6 and biochemical ball C7 (glass ring) in turn to the water storage chamber of the clean water pool C4. When the aerator C8 in the water storage chamber detects that the dissolved oxygen in the water is lower than 5mg / L, it automatically adds oxygen to the water storage chamber until it is no less than 5mg / L and automatically stops adding oxygen.

[0043] (2) Water Intake: After aeration is complete, open valve C10 of pump C9, then open pump C9. Oxygen-rich water enters pool B1 from the top of pool B1 via inlet pipe C11. Once the water intake is complete, turn off pump C9 and then the inlet valve. While the water is inflowing, drainage is completed, and water purification continues until both purification and aeration are complete. The entire water cycle ends, and the next water change is scheduled. After the water intake is complete, install the cleaned baffles B4 and soundproofing pads B3.

[0044] During the experiment, a thermometer D1 was placed in each pool B1 to regularly measure the water temperature, maintaining it at an appropriate level and preventing excessive temperature fluctuations. The water temperature was automatically regulated by a temperature control system D, a temperature-regulating blanket installed at the bottom of pool B1. The blanket, placed directly in contact with pool B1, was evenly layered with a highly thermally conductive material D2, such as aluminum. This blanket autonomously exchanged heat with the surrounding water, maintaining the desired temperature. Thermometer D1 also indirectly monitored water quality. If the water temperature was abnormal or the regulation was weak, it was suspected that the water was contaminated with microorganisms or contaminants, necessitating water purification and water changes.

[0045] To assist the smooth progress of the test, it is necessary to eliminate other external sound sources and prevent the interference of changing light intensity, which requires sound insulation and dimming. Figure 6 Pool B1 is surrounded by soundproof and dimming glass, including the left panel E1, rear panel E2, front panel E3, right panel E4, and top panel E5. Space is reserved at the bottom for a temperature-regulating blanket, and no soundproof and dimming glass is installed. The surrounding soundproof and dimming glass blocks ambient noise and stabilizes the light passing through pool B1. After the experimental fish were placed in pool B1, the soundproof and dimming glass was installed to isolate ambient noise while preventing interference with the experimenter's observation of the fish's well-being. The light source is electrically controlled, adjusting the amount of light passing through the glass to stabilize the light level in pool B1. Before the experiment, to control experimental variables, the amount of light passing through the glass was set to a fixed value suitable for the fish's well-being.

[0046] Matters not covered by this invention are known technologies. The method and system of the present invention automatically adjust underwater noise characteristics, adjust fish living space, regulate water temperature, achieve water circulation, isolate ambient noise, and regulate light. A computer control terminal controls noise variations under different time conditions, while the power amplifier control terminal A1 adjusts the sound pressure level. Slots B2 are provided along the edge of pool B1 to adjust the size of each pool B1 to achieve an appropriate fish stocking density. By providing different amounts of sound insulation cotton B3, different gradients of underwater noise pressure levels can be established, allowing for more experimental controls. A temperature-regulating blanket automatically adjusts the water temperature to maintain an appropriate temperature, and a thermometer D1 is used to measure water temperature and monitor water quality. The water circulation system C provides drainage, sewage purification, and water storage, effectively improving the water quality of pool B1. Sound-insulating and dimming glass is installed around pool B1 to control variables without interfering with experimental observations. This invention provides a more scientific, environmentally friendly, and convenient experimental system and method for testing the effects of underwater noise on fish growth, providing a reference for subsequent experimental devices.

[0047] The above embodiments are intended only to illustrate the technical concepts and features of the present invention. Their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. They are not intended to limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit of the present invention are intended to be covered by the scope of protection of the present invention.

Claims

1. A test system for the effect of underwater noise on fish growth, characterized in that: It includes noise change system (A), size adjustment system (B), water circulation system (C), temperature control system (D) and sound insulation and dimming system (E); The noise variation system (A) consists of a computer control terminal, an amplifier adjustment terminal (A1), and an underwater speaker (A2). The underwater noise recorded at the waterway site is fed into the computer control terminal to simulate the noise sound pressure levels during the day and night, as well as the underwater noise cycle during flood, dry, and normal water periods. The power amplifier adjustment terminal (A1) adjusts the sound pressure level based on the sound source and can set more sound pressure level gradients to analyze the impact of more noise characteristic changes on fish. The underwater speaker (A2) is placed under the pool (B1) to simulate underwater noise propagation, and the other end is directly connected to the power amplifier adjustment terminal (A1). A size adjustment system (B) includes an adjustable pool (B1), slots (B2) are provided along the left and right edges of the entire pool (B1), a baffle (B4) is placed in each slot (B2), the baffle (B4) moves forward and backward to change the size of each pool (B1) and the distance of each pool (B1) relative to the underwater speaker (A2), and sound insulation cotton (B3) is installed between adjacent slots (B2); Water circulation system (C): removes insoluble impurities, waste, and harmful substances soluble in water from the water in the pool (B1), converts toxic substances produced by fish metabolism into non-toxic substances, adjusts the pH value of the water, and circulates the water back into the pool (B1); A temperature control system (D) comprising a temperature regulating blanket laid at the bottom of the pool (B1) to provide insulation and temperature control; Sound insulation and dimming system (E): includes laying a layer of sound insulation and dimming glass outside the pool (B1), including a left panel (E1), a rear panel (E2), a front panel (E3), a right panel (E4), and a top panel (E5); blocking environmental noise.

2. The underwater noise impact on fish growth test system according to claim 1, characterized in that: The water circulation system (C) comprises a water supply pipe, a water purification pool (C4), and a water pump (C9); the water purification pool (C4) is located in front of the pool (B1) and is connected to the pool (B1) through the water supply pipe; the water supply pipe is divided into a drainage pipe (C2) and a water inlet pipe (C11); the inlet of the drainage pipe (C2) is located at the bottom of the pool (B1), and the inlet section is sealed with a cap (C1); the drainage pipe (C2) has a total of four drainage branches and a drainage main pipe, and a drainage valve (C3) is located at the outlet of the drainage main pipe. When it is necessary to change the water in the pool (B1), the caps (C1) of the drainage branches and the drainage valve (C3) of the drainage main pipe are opened; the drainage main pipe leads to the water purification pool (C4); and further comprises The invention comprises three filter screens, namely filter cotton (C5), activated carbon (C6) and biochemical ball (C7), which divide the water purification pool (C4) into four parts. In the fourth part of the water purification pool (C4), there is a water pump (C9) for inputting the purified water into the water pool (B1). There is a water inlet switch valve near the water pump (C9), and the water inlet pipe (C11) leads from the top of the water pool (B1) into the water pool (B1); the aerator (C8) is also set in the fourth part of the water purification pool (C4). When the dissolved oxygen is lower than a certain value, the aerator (C8) automatically opens. When the dissolved oxygen reaches an appropriate level, the water pump valve (C10) is opened to discharge the water into the water pool (B1).

3. A test method for the effect of underwater noise on fish growth, characterized in that: The method of testing the effect of underwater noise on fish growth according to claim 1 or 2 comprises the following steps: The cycle period and sound pressure level of underwater noise were adjusted to simulate the noise characteristics during the day, night, and during the flood, dry and normal water seasons. After controlling the water temperature, ensuring the water quality, isolating the environmental noise and stabilizing the light, noise was used as the only variable in the experiment. Different noise sound pressure level gradients were set to conduct multiple groups of experimental controls.

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