Apparatus and methods for studying the effects of water turbulence on the development of drifting fish eggs

Abstract

This invention provides an apparatus and method for studying the influence of water turbulence on the development of drifting fish eggs, relating to the field of ecohydraulics. Its main purpose is to reduce potential experimental errors in traditional experimental setups, explore the degree and changes in the influence of water turbulence on the entire development process of drifting fish eggs, and provide a new experimental apparatus and a new experimental method based on this apparatus. The apparatus for studying the influence of water turbulence on the development of drifting fish eggs includes an experimental chamber, a net cage, and a detection unit. The experimental chamber is equipped with a turbulence simulation unit, and the water within the experimental chamber experiences water turbulence under the action of the turbulence simulation unit. The net cage is positioned within the water body and spaced apart from the turbulence simulation unit. At least a portion of the detection unit is located within the water body of the experimental chamber to detect the water turbulence.

Description

Technical Field

[0001] This invention relates to the field of ecohydraulics, and in particular to an apparatus and method for studying the effects of water turbulence on the development of drifting fish eggs. Background Technology

[0002] Fish occupy the top of the food chain in river ecosystems and are often used as an indicator of the quality of river ecological environment. The complex hydrodynamic environment in rivers has a significant impact on fish eggs; strong turbulent water flow can lead to premature hatching, developmental deformities, and death of fish eggs. Current research on the impact of water flow turbulence on fish growth and development mainly focuses on the adult stage, with little attention paid to fish eggs. Foreign scholars Morgan et al. (1976) mentioned using a circular rotating chamber to investigate the damage of water flow shear force to white bass and striped bass eggs, while Prada Sepulveda et al. (2020) proposed using a vertical vibrating grid tank to investigate the threshold of water flow turbulence and shear force on grass carp eggs.

[0003] To better study the impact of water turbulence on fish egg development, a device capable of artificially simulating water turbulence is needed, such as the device disclosed in CN113951187A. In this device, the motion device used to generate turbulence is located in the same chamber as the fish eggs and can directly contact them. At this time, the fish eggs in the incubation stage will be damaged by both water turbulence and collisions with the motion device, making it difficult for researchers to separate collision damage from experimental results. In addition, the above-mentioned device will also cause uneven distribution of water turbulence within the device, resulting in varying degrees of water turbulence experienced by fish eggs in different areas, making it difficult to accurately determine the damage caused by turbulence to the fish eggs, thus leading to an inaccurate experimental structure. Most importantly, the above-mentioned device places the fish eggs and the motion device in the same environment, which directly affects the recovery of fish eggs and the acquisition of fish egg survival rate.

[0004] To address the problems with the aforementioned devices, minimize the impact of sports injuries on fish egg survival rates, obtain more accurate experimental results, and overcome the difficulty in fish egg retrieval, a novel experimental device and method need to be developed. Summary of the Invention

[0005] The purpose of this invention is to provide an apparatus and method for studying the influence of water turbulence on the development process of drifting fish eggs, in order to solve the error problems that may exist in the use of experimental equipment in the prior art, and to explore the degree and changes of the influence of water turbulence on the entire development process of drifting fish eggs. The various technical effects produced by the preferred technical solutions provided by this invention are described in detail below.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] This invention provides an apparatus for studying the effects of water turbulence on the development of drifting fish eggs, comprising an experimental chamber, a net cage, and a detection unit, wherein:

[0008] The experimental chamber is equipped with a turbulence simulation unit. The water body located in the experimental chamber can generate water flow turbulence under the action of the turbulence simulation unit. The containment net box is arranged in the water body and there is a gap between it and the turbulence simulation unit. At least part of the detection unit is located in the water body of the experimental chamber to detect the turbulence of the water body.

[0009] By adding a net cage inside the experimental chamber, not only can the deployment and retrieval of fish eggs be conveniently and quickly achieved, but the eggs can also be separated from the turbulence simulation unit, preventing contact and collision damage during the experiment and eliminating mechanical damage errors. Furthermore, the net cage helps limit the movement range of the fish eggs, ensuring relatively stable water turbulence at the egg location and further ensuring the accuracy of the experimental results.

[0010] Based on the above technical solution, the present invention can be further improved as follows.

[0011] As a further improvement of the present invention, the turbulence simulation unit includes symmetrically arranged turbulence generating components, and the accommodating cage is located between two of the turbulence generating components.

[0012] By symmetrically arranging the turbulence generating components and placing the containment cage between two turbulence generating components, the stability and uniformity of water flow turbulence at the location of the containment cage can be further improved, thereby accurately obtaining the damage effect of water flow turbulence on fish eggs.

[0013] As a further improvement of the present invention, the turbulence generating component includes a grid, a transmission mechanism and a driving member. The grid is arranged vertically inside the experimental chamber, the driving member is located outside the experimental chamber, and the transmission mechanism passes through the experimental chamber and is connected to the grid and the driving member respectively. When the driving member is activated, the grid can reciprocate along a fixed path under the drive of the driving member.

[0014] The coordination of the drive component and the transmission structure enables the screen to reciprocate within a certain range, thereby simulating the hydrodynamic conditions under natural conditions. Furthermore, by controlling the drive component, the vibration frequency of the screen can be adjusted, thus providing different water flow turbulence and facilitating the simulation of various water flow scenarios.

[0015] As a further improvement of the present invention, the porosity of the grid is 0.45 to 0.6.

[0016] As a further improvement of the present invention, the accommodating cage includes a support frame and a wrapping net, wherein the wrapping net is a nylon hexagonal mesh and the mesh size of the wrapping net is 1-2 mm.

[0017] As a further improvement of the present invention, the experimental chamber is covered with a cover plate, and there is a gap between the water and the cover plate.

[0018] The aforementioned gaps allow the water inside the experimental chamber to ripple freely, thereby increasing the internal turbulence of the water and better simulating the turbulent characteristics of natural river flow.

[0019] As a further improvement of the present invention, the detection unit includes a probe, and the number of the probes is at least one and located in the water body of the experimental chamber.

[0020] The present invention also provides a method for studying the effect of water turbulence on the development of drifting fish eggs, comprising the apparatus described in any of the above claims, and further comprising the following steps:

[0021] The turbulence of the water flow inside the experimental chamber is obtained, and the arrangement position of the containment net cage is determined;

[0022] A fixed quantity of fish eggs is placed in the containment net cage, and the survival rate of the fish eggs is detected and calculated under the same turbulent conditions at set intervals.

[0023] This method can study the impact of water turbulence on different developmental stages of fish eggs by detecting the survival rate of drifting fish eggs under fixed water turbulence conditions, and helps to clarify the dynamic impact of the same water turbulence conditions on different early developmental stages of fish.

[0024] As a further improvement of the present invention, the fish eggs placed in the accommodating net cage are at the same developmental stage; and / or, the fish eggs at different developmental stages are taken for repeated experiments through group experiments.

[0025] To ensure the accuracy of the experimental results, it is necessary to ensure that the fish eggs selected in the same experiment are all at the same developmental stage. Furthermore, to facilitate the assessment of the sensitivity of fish eggs at different developmental stages to the same turbulent water conditions, the above experimental process can be repeated using a group experiment, selecting fish eggs at different developmental stages to investigate the extent to which turbulent water conditions affect the entire development process of drifting fish eggs and the corresponding changes.

[0026] As a further improvement of the present invention, it also includes: taking a certain amount of fish eggs and placing them in the containment net cage, and obtaining the fish egg survival rate under different turbulence conditions through group experiments;

[0027] Different turbulence conditions can be obtained by adjusting the operating frequency and / or operating time of the turbulence simulation unit.

[0028] To study the effects of different turbulence conditions on fish egg development, experiments can be conducted on fish eggs at a certain developmental stage under different turbulence conditions based on previous research. This will determine the impact of turbulence intensity and duration on fish egg development, thereby clarifying the dynamic influence of different water flow turbulence on different stages of fish egg development.

[0029] Compared with the prior art, the preferred embodiment of the present invention provides the following beneficial effects:

[0030] Compared to traditional equipment and research methods, this approach effectively reduces or even avoids mechanical collisions between fish eggs and moving equipment by improving the structure of the experimental setup. It focuses solely on the impact of water turbulence on fish egg development, thus improving the accuracy of the experimental results. Furthermore, by using a net cage to confine the fish eggs to an area with relatively uniform and constant water turbulence distribution, it not only helps to accurately determine the water turbulence damage threshold of the fish eggs but also reduces the difficulty of egg retrieval, avoiding experimental bias caused by incomplete retrieval. Through the aforementioned setup and experimental methods, it is also possible to clarify the dynamic impact of water turbulence on different stages of fish egg development, as well as the influence of different water turbulence conditions on fish eggs at the same developmental stage. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the device used in this invention to study the effects of water turbulence on the development of drifting fish eggs;

[0033] Figure 2 This is a flowchart of one embodiment of the method of the present invention for studying the effect of water flow turbulence on the development process of drifting fish eggs.

[0034] In the figure: 1. Experimental chamber; 2. Mesh cage; 3. Turbulence generating component; 31. Grille; 32. Transmission mechanism; 33. Driving component; 4. Cover plate; 5. Fixing clamp; 6. Support frame. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0036] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0037] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0038] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

[0039] This invention provides an apparatus for studying the influence of water turbulence on the development of drifting fish eggs, comprising an experimental chamber 1, a net cage 2, and a detection unit. The experimental chamber 1 is used to contain water and simulate a river channel. The experimental chamber 1 is equipped with a turbulence simulation unit, which generates water turbulence under the action of the turbulence simulation unit. The net cage 2 is arranged in the water body and has a certain distance between it and the turbulence simulation unit. At this time, the experimental fish eggs in the net cage 2 can be isolated from the turbulence simulation unit, avoiding collisions and mechanical damage between the fish eggs and the turbulence simulation unit. At least part of the detection unit is located in the water body of the experimental chamber 1, thereby achieving accurate detection of water turbulence.

[0040] By adding a net cage 2 inside the experimental chamber 1, not only can the deployment and retrieval of fish eggs be conveniently and quickly achieved, but the fish eggs can also be separated from the turbulence simulation unit, preventing contact and collision damage between the fish eggs and the turbulence simulation unit during the experiment, thus achieving the removal of mechanical damage. In addition, the net cage 2 can also help limit the movement range of the fish eggs, thereby ensuring that the magnitude of water turbulence at the location of the fish eggs is relatively stable, further ensuring the accuracy of the experimental results.

[0041] It should be noted that, in order to ensure accurate detection of the positional disturbance of the cage 2, it is necessary to ensure that the part of the detection unit located inside the experimental chamber 1 can be inserted into the cage 2.

[0042] Example 1:

[0043] like Figure 1 As shown, this invention provides an apparatus for studying the influence of water turbulence on the development of drifting fish eggs. The apparatus includes an experimental chamber 1, a net cage 2, and a detection unit. The experimental chamber 1 is used to contain water and simulate water turbulence in a natural river channel. The experimental chamber 1 is equipped with a turbulence simulation unit, which generates turbulence in the water. The turbulence simulation unit includes symmetrically arranged turbulence generating components 3. The net cage 2 is located between two turbulence generating components 3 and has a certain distance between it and the turbulence simulation unit. This isolates the experimental fish eggs inside the net cage 2 from the turbulence simulation unit, preventing collisions and mechanical damage. The detection unit is an ADV (Acoustic Doppler Velocimetry), used to measure the water turbulence in the experimental chamber 1 and the net cage 2. The ADV includes at least one probe, and all probes are located within the water in the experimental chamber 1, thereby achieving accurate detection of water turbulence.

[0044] By symmetrically arranging the turbulence generating components 3 and placing the containment cage 2 between the two turbulence generating components 3, the stability and uniformity of the water flow turbulence at the location of the containment cage 2 can be further improved, thereby accurately detecting the damage effect of water flow turbulence on fish eggs.

[0045] In this embodiment, the experimental chamber 1 is made of transparent material to facilitate observation of the water conditions by the experimenters. The net cage 2 includes a supporting frame and a wrapping net, which is a nylon hexagonal mesh with a mesh size of 1-2 mm. To facilitate the placement and removal of fish eggs while ensuring the airtightness of the net cage 2, one side of the net cage 2 has an opening via a zipper. When setting up the net cage 2, the vertical distribution of water turbulence needs to be measured using the aforementioned ADV device to determine the placement height of the net cage. In actual operation, the probe of the ADV needs to be inserted into the net cage 2 for measurement (through the opening at the zipper).

[0046] Specifically, the aforementioned turbulence generating component 3 includes a grid 31, a transmission mechanism 32, and a driving component 33. The grid 31 is arranged vertically inside the experimental chamber 1, the driving component 33 is located outside the experimental chamber 1, and the transmission mechanism 32 passes through the experimental chamber 1 and is connected to the grid 31 and the driving component 33 respectively. When the driving component 33 is activated, the grid 31 can reciprocate along a fixed path under the drive of the driving component 33 (at this time, the two grids 31 can move closer or further away from each other, or the two grids 31 can reciprocate synchronously).

[0047] The cooperation between the drive component 33 and the transmission structure enables the grille 31 to reciprocate within a certain range, thereby driving the water flow to simulate the hydrodynamic conditions under natural conditions. At this time, by controlling the drive component 33, the vibration frequency of the grille 31 can be adjusted, thereby generating different water flow turbulence conditions.

[0048] In this embodiment and similar embodiments, the driving component 33 is a geared motor, and the grille 31 can be connected to the geared motor through the transmission mechanism 32. The geared motor can drive the grille 31 to vibrate and can generate stepless frequency modulation, so as to realize the vibration of the grille 31 in the experimental chamber 1 and drive the water flow to generate water flow turbulence conditions similar to those in natural conditions.

[0049] Specifically, the aforementioned grid 31 has a plurality of grid holes evenly distributed on it. The porosity of the grid 31 (the ratio of the area occupied by the grid holes to the total area of ​​the grid 31) is 0.45 to 0.6, preferably 0.56.

[0050] Generally, the experimental chamber 1 is filled with water, leaving no free surface, and covered on top. This ensures that the turbulence generated inside the water tank is approximately isotropic within a certain range. However, the resulting water flow turbulence is relatively small, differing significantly from the turbulence conditions in natural river channels. To further increase the upper limit of the turbulence intensity generated by this device, it is necessary to ensure that there is a certain space between the free surface of the water and the upper edge of the experimental chamber 1.

[0051] Specifically, a 5cm space is reserved between the upper edge of the experimental chamber 1 and the free surface of the water body to allow the water flow to ripple freely, increasing the turbulence inside the water body and better simulating the turbulence characteristics of natural river flow.

[0052] To prevent water from splashing out of the experimental chamber 1 due to vibration, as an optional implementation, a cover plate 4 is provided on the experimental chamber 1, with a gap between the water and the cover plate 4. The cover plate 4 is sealed to the experimental chamber 1 by adhesive bonding with a material such as industrial putty, and is simultaneously clamped and fixed using a fixing clip 5 (F-type woodworking clip). Figure 1 As shown.

[0053] To avoid the cover plate 4 affecting the installation and arrangement of the ADV, in this embodiment and similar embodiments, the cover plate 4 is composed of two plate-shaped components spliced ​​together. The main unit of the ADV device is supported and fixed above the experimental chamber 1 by a corresponding support frame 6. The gap between the plates facilitates the insertion of the probe into the water, and the splice can be sealed with sealing strips or the like. The probe, placed in the water, can detect the instantaneous flow velocity at a certain distance (about 5 cm) in front of it. Its measurement frequency is 200 Hz, the measurement range can reach 4 m / s, and the accuracy is ±0.5% of the measurement range.

[0054] It should be noted that the aforementioned support frame 6 can drive the ADV equipment to move freely in different directions such as up and down, front and back, and left and right relative to the experimental chamber 1, thereby realizing the detection of water flow conditions at different locations in the water body.

[0055] In this embodiment, turbulent kinetic energy and shear stress are used to characterize the turbulence of the water flow, and their values ​​can be obtained by the ADV device described above.

[0056] Turbulent kinetic energy (k) is a physical quantity that characterizes the strength of turbulence in water flow, and its calculation formula is as follows:

[0057]

[0058]

[0059]

[0060] In the formula, u′, v′, w′ are the root mean square of the pulsating velocity (i.e., the turbulence intensity), u′ i , v′ i , w′ i For the pulsating flow velocity in three directions, u i v i w i Instantaneous flow velocity measured by ADV The average flow rate is N, and the total number of measurement samples is N.

[0061] Shear stress (τ, Reynolds shear stress) is the apparent stress associated with turbulent flux transport, and its calculation formula is:

[0062]

[0063] In the formula, ρ is the density of water (taken as 996.782 kg / m³ at a water temperature of 26℃). 3 ), u′ i and u′ j This represents the pulsating flow velocity in different directions. Since we are more concerned with the effect of large shear forces on fish eggs, we take τ as τ_0. ij The maximum value in.

[0064] The location of the cage 2 can be determined based on the spatial distribution of turbulent kinetic energy and shear stress calculated using the above formula.

[0065] In this embodiment, a vertical position with relatively large and evenly distributed turbulent kinetic energy or shear stress is selected as the placement height of the mesh box 2. Preferably, the mesh box 2 is placed 10cm away from the bottom of the water tank. At this time, the opening of the mesh box 2 is placed vertically upward so that the ADV probe can be inserted into the mesh box 2.

[0066] Inserting the ADV probe into the enclosure 2 ensures that the center of the enclosure is 5cm in front of the probe, allowing for more accurate acquisition of the water turbulence conditions in the environment of the experimental subjects (i.e., fish eggs, etc.).

[0067] The following is a structural example of this experimental setup:

[0068] The experimental chamber 1 is a horizontal water tank made of transparent plexiglass, with dimensions of 55cm×30cm×30cm (length×width×height). It is used to hold water and, together with the turbulence generating component 3, quantitatively generates the water flow turbulence conditions required for the experiment.

[0069] The two turbulence generating components 3 are symmetrically arranged, including a grid 31, a transmission mechanism 32, and a drive component 33, as well as a frequency converter. The grid 31 has overall dimensions of 28cm × 28cm × 1cm (length × width × thickness), is made of aluminum alloy, and has square holes measuring 3cm × 3cm (length × width). The center-to-center distance between two adjacent grid holes is 4cm. The vibration centers of the two grids 31 are located 10cm from the side wall inside the experimental chamber 1, and the distance between the two grids 31 is 35cm. The drive component 33 is a 1100W horizontal geared motor. Two motors are respectively arranged on both sides outside the experimental chamber 1 and connected to the grids 31 inside the experimental chamber 1 via the transmission mechanism 32, driving the grids 31 to reciprocate. The amplitude of the grid 31 is 10cm. Two frequency converters are used to quantitatively control the two motors for stepless speed regulation, with a vibration frequency range of 0–7Hz.

[0070] In this embodiment, the selected ADV device is a single-point measurement device.

[0071] In this embodiment, the dimensions of the aforementioned accommodating cage 2 are 10cm×7cm×10cm (length×width×height), its supporting frame is made of plastic, the wrapping net is made of nylon hexagonal mesh, the mesh size is 1~2mm, and the size of the opening formed on a certain side wall is 10cm×7cm (length×width).

[0072] Understandably, the improved experimental setup can effectively avoid mechanical collisions between fish eggs and the turbulence-generating component 3, allowing the study to focus solely on the impact of water turbulence on fish egg development, thus improving the accuracy of the experimental results. Furthermore, by using the containment net cage 2 to confine the fish eggs within an area where water turbulence is relatively uniform and constant, it not only helps to accurately determine the water turbulence damage threshold of the fish eggs but also reduces the difficulty of fish egg retrieval, avoiding experimental deviations caused by incomplete retrieval.

[0073] Example 2:

[0074] This embodiment provides a method for studying the effect of water turbulence on the development process of drifting fish eggs, including the apparatus described in any of the above-mentioned embodiments, and further including the following steps:

[0075] Step S1: Obtain the spatial distribution of water turbulence within the experimental chamber 1 and determine the placement position of the cage 2;

[0076] Step S2: Take a certain amount of fish eggs and place them in the containment net cage 2. At set intervals, detect and calculate the survival rate of the fish eggs under the same turbulent conditions.

[0077] This method can study the impact of water turbulence on different developmental stages of fish eggs by observing the survival of fish eggs under fixed water turbulence conditions, and helps to clarify the dynamic influence of the same water turbulence conditions on different developmental stages of fish eggs.

[0078] It should be noted that before performing step S1, the corresponding experimental apparatus needs to be constructed based on the above information. Subsequently, the apparatus is used to conduct several repeated experiments to select and determine the water flow turbulence conditions and the actual placement position of the cage 2 for subsequent experiments (when determining the vertical height of the cage 2, the cage needs to be removed for measurement to determine the vertical water flow turbulence distribution within the experimental chamber 1).

[0079] Furthermore, the survival rate of the fish eggs can be obtained from the change in their total volume. Compared with traditional microscopic observation, this method is simpler, more efficient, and more intuitive.

[0080] Specifically, fish eggs are selected and placed in an incubation tank for later use. Once the eggs have absorbed water and swelled in the incubation tank, and their size and bulk density have stabilized, the experiment can be conducted. After the experiment begins, fish eggs at the appropriate developmental stage are collected and their volume (V1) is measured using a graduated cylinder to estimate the number of eggs. After the experiment is completed, the volume (V2) of the eggs is measured again to estimate their quantity.

[0081] Turbulent water flow can cause some fish eggs to rupture prematurely, leading to death or developmental abnormalities. The egg volume before (V1) and after (V2) the experiment can be measured using a graduated cylinder. Rupture of the egg membrane results in a decrease in egg volume. The percentage of eggs that did not rupture (i.e., eggs that can continue to develop normally) is the ratio of V2 to V1 (P). (experiment), Eq.(1)).

[0082] Besides water turbulence, normal experimental procedures may also cause premature detachment of the egg membrane. At different stages, the experimental process may cause different damage to the fish eggs. Therefore, to ensure the accuracy of the experimental results, a blank control experiment (i.e., simulating the entire experimental process using only a still water environment) was required for each group of experiments, and the data obtained from the normal experiment was corrected based on the data from the blank experiment. The percentage of fish eggs that could develop normally under typical water turbulence conditions after correction was taken as the survival rate of the fish eggs (P0, Eq. (2)).

[0083]

[0084]

[0085] In the above text, P (experiment) , is the percentage of unshed fish eggs obtained in the experiment, P (blank)P0 is the percentage of fish eggs that have not molted in the blank control group. P0 is the percentage of fish eggs that can develop normally under typical turbulent water conditions after correction, which is the final fish egg survival rate.

[0086] To ensure the accuracy of the experimental results and to investigate the effect of water turbulence on the survival rate of fish eggs at different developmental stages, as an optional implementation method, the fish eggs placed in the containment net cage 2 are at the same developmental stage; and / or, the experiment is repeated by taking fish eggs at different developmental stages in a group experiment.

[0087] To ensure the accuracy of the experimental results, it is necessary to ensure that the fish eggs selected for the same experiment are all at the same developmental stage. Furthermore, to facilitate the assessment of the response of fish eggs at different developmental stages to the same turbulent water flow conditions, it is necessary to repeat the above experimental process by selecting fish eggs at different developmental stages in a group experiment.

[0088] The aforementioned time setting can be a fixed unit of time or an interval determined based on experience or experimental results. In this embodiment, an interval of 0.5 to 2 hours is used to distinguish different developmental stages of fish eggs.

[0089] The following section uses the fertilized eggs of red-eyed trout as the experimental subject to explain the above experimental procedure in detail:

[0090] After obtaining the above experimental equipment, in order to investigate the influence of the same turbulent water flow conditions on fish eggs at different developmental stages, this experimental method used the development time after fertilization as a single variable, and selected a vibration frequency of 5 Hz and an action time of 1 min as typical turbulent water flow conditions (the turbulent kinetic energy generated under this condition is k = 0.157 m). 2 / s 2 The shear stress is τ = 19.93 N / m. 2 Repeat the experiment multiple times without changing the parameters.

[0091] Considering that the hatching time of red-eyed trout is about 16 to 18 hours after fertilization, and that they are most affected by water turbulence before and after hatching, the experimental time intervals were set as follows: once every two hours for the first 10 hours, once every hour for 10 to 14 hours, and once every half hour for 14 to 20 hours, as shown in the table below.

[0092]

[0093] By following the above experimental steps, the survival rate of fish eggs at different developmental stages under typical turbulent water conditions can be obtained, thus revealing the extent to which the same turbulent water conditions affect fish eggs at different developmental stages.

[0094] During the experiment, it is necessary to record the specific time and water temperature.

[0095] It is understandable that the experimental method provided in this embodiment can help study the dynamic effects of water turbulence on different stages of fish egg development.

[0096] Example 3:

[0097] Compared with Example 2, Example 3 also includes the following:

[0098] The method also includes:

[0099] Step S3: Take a certain amount of fish eggs and place them in the containment net cage 2, and obtain the fish egg survival rate under different turbulence conditions through group experiments; different turbulence conditions can be obtained by adjusting the frequency and / or duration of the turbulence simulation unit.

[0100] Step S3 can be used to investigate the different effects of varying water flow turbulence intensities and durations on fish egg development.

[0101] In this embodiment, fish eggs selected in step S2 with a survival rate of P0≈75% (this data is an empirical value, as fish eggs in this stage are highly sensitive to water turbulence) are used for step S3. Of course, corresponding developmental stages with fish egg survival rates higher or lower than 75% can also be selected according to the actual situation, such as stages with a survival rate of around 60% or around 80%.

[0102] It should be noted that step S3 only selects fish eggs at the corresponding developmental stage selected in step S2, and does not select fish eggs that have undergone the experimental operation in step S2.

[0103] At this point, multiple sets of experiments can be conducted by setting the vibration frequency and duration of the turbulence-generating component 3 as variables. The specific experimental details are shown in the table below:

[0104]

[0105]

[0106] The above steps can help determine the effects of different water turbulence intensities and durations on specific developmental stages of fish eggs.

[0107] It is understandable that, such as Figure 2 As shown, the experimental method provided in this embodiment can help study the effects of different water turbulence conditions on the development process of fish eggs.

[0108] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An apparatus for studying the effects of water turbulence on the development of drifting fish eggs, characterized in that, It includes an experimental chamber, a mesh enclosure, and a testing unit, wherein: The experimental chamber is equipped with a turbulence simulation unit. The water body located in the experimental chamber can generate water flow turbulence under the action of the turbulence simulation unit. The containment net box is arranged in the water body and there is a gap between it and the turbulence simulation unit. At least part of the detection unit is located in the water body of the experimental chamber to detect the turbulence of the water body. The turbulence simulation unit includes symmetrically arranged turbulence generating components, and the accommodating cage is located between two of the turbulence generating components; The turbulence generating component includes a grid, a transmission mechanism, and a driving component. The grid is arranged vertically inside the experimental chamber, the driving component is located outside the experimental chamber, and the transmission mechanism passes through the experimental chamber and is connected to the grid and the driving component respectively. When the driving component is activated, the grid can reciprocate along a fixed path under the drive of the driving component. The experimental chamber is covered with a cover plate, and there is a gap between the water and the cover plate; The detection unit includes a probe, and the number of the probes is at least one and is located in the water body of the experimental chamber.

2. The apparatus for studying the effect of water turbulence on the development process of drifting fish eggs according to claim 1, characterized in that, The porosity of the grid is 0.45~0.

6.

3. The apparatus for studying the effect of water turbulence on the development process of drifting fish eggs according to claim 1, characterized in that, The cage includes a support frame and a wrapping net, wherein the wrapping net is a nylon hexagonal mesh with a mesh size of 1-2 mm.

4. A method for studying the effects of water turbulence on the development of drifting fish eggs, characterized in that, The apparatus comprising any one of claims 1-3 further comprises the following steps: The turbulence of the water flow inside the experimental chamber is obtained, and the arrangement position of the containment net cage is determined; A fixed quantity of fish eggs is placed in the containment net cage, and the survival rate of the fish eggs is detected and calculated under the same turbulent conditions at set intervals.

5. The method for studying the influence of water turbulence on the development of drifting fish eggs according to claim 4, characterized in that, The fish eggs placed in the containment cage are at the same developmental stage; and / or, the experiments are repeated by taking fish eggs at different developmental stages in group experiments.

6. The method for studying the influence of water turbulence on the development of drifting fish eggs according to claim 4, characterized in that, Also includes: A fixed amount of fish eggs were placed in the containment net cage, and the survival rate of the fish eggs under different turbulent conditions was obtained through group experiments. Different turbulence conditions can be obtained by adjusting the operating frequency and / or operating time of the turbulence simulation unit.

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