An aquatic organism eDNA sampler and a sampling method carried on a drone

Abstract

This invention proposes an aquatic organism eDNA sampler and sampling method mounted on a drone, comprising a traction mechanism connected to the drone and a sampling body; the sampling body has a streamlined head and a rectangular sampling channel at the rear; a cover is provided on the top of the sampling channel, the cover is hinged to the sampling body, and the cover can be opened when flipped up; multiple first sampling ports are provided on the bottom surface of the head, and second sampling ports are provided on the side of the head, the first and second sampling ports are connected to the rectangular portion; the traction mechanism includes a rigid connecting rod and multiple traction rings provided on the rigid connecting rod; an in-situ water flushing device is provided inside the head, and the in-situ water flushing device is connected to the sampling channel through a pipeline; the sampling channel is divided from front to back into a filtration cavity, a mud mixing cavity, and a collection cavity, a filter screen is provided in the filtration cavity, and a collection box is provided in the collection cavity; a one-way valve is provided on the partition between the mud mixing cavity and the collection cavity, and an interface for connecting the one-way valve is provided on the collection box.

Description

Technical Field

[0001] This invention belongs to the field of unmanned aerial vehicle (UAV) application technology, and in particular relates to an aquatic organism eDNA mud sampler and mud sampling method mounted on a UAV. Background Technology

[0002] In the construction of ecological health assessment methods, eDNA technology refers to the technology of directly extracting DNA fragments from environmental samples (water, soil, sediment, etc.) and then using sequencing technology for qualitative or quantitative analysis to determine the species and quantity of organisms in the sampled environment, so as to achieve the purpose of species monitoring.

[0003] Traditional eDNA sampling is highly dependent on human labor, requiring personnel to reach the water's edge for operation, thus limiting its applicability. It is virtually impossible to implement in swamps, deep water areas, or dangerous or remote waters. Furthermore, low biomass coverage cannot meet the needs of large-scale, high-density sampling. The risk of cross-contamination with eDNA is extremely high; even after washing, reused sampling bottles, buckets, and filters cannot guarantee the complete removal of residual DNA, easily leading to false positives. With the development of current eDNA technology, the collection and analysis of environmental samples are increasingly being undertaken by autonomous mobile devices such as drones.

[0004] Existing drone mounting solutions only involve simple hoisting or insertion, and sampling is performed at points through mechanical handling, failing to achieve dynamic, continuous, and automated sampling based on a mobile platform. Summary of the Invention

[0005] To address the aforementioned problems, this invention proposes an aquatic organism eDNA sampler and sampling method mounted on a drone. This aquatic organism eDNA sampler can be deeply integrated with the dynamic operation of the drone, achieving a fully enclosed process and pollution prevention, thereby fundamentally solving the core problems of low sampling efficiency, high pollution risk, and insufficient utilization of mobile platforms in existing technologies.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: In the first aspect, the present invention proposes an aquatic organism eDNA mud sampler mounted on a drone, which mainly includes a drone, a traction mechanism connected to the drone, and a sampling body. The sampling body has a streamlined head and a rectangular sampling channel at the rear. A cover is provided at the top of the sampling channel, which is hinged to the sampling body and can be flipped up and opened. The bottom surface of the head has multiple first sampling ports, and the side surface of the head has a second sampling port. The first and second sampling ports are connected to the rectangular portion. The traction mechanism includes a rigid connecting rod at the tip of the sampling body head and multiple traction rings of different heights on the rigid connecting rod. An in-situ water flushing device is provided inside the head and is connected to the sampling channel through a pipeline. The sampling channel is divided into a filtration cavity, a mud mixing cavity, and a collection cavity from front to back. A filter screen is provided in the filtration cavity, and a collection box is provided in the collection cavity. A one-way valve is provided on the partition between the mud mixing cavity and the collection cavity, and an interface for connecting the one-way valve is provided on the collection box.

[0007] As a further technical solution, the aforementioned first injection port has an arc-shaped protrusion with the bottom surface of the head facing downwards. The front end of the arc-shaped protrusion is open, and the rear end is connected to the interface of the sampling channel. As a further technical solution, the aforementioned second injection port has an arc-shaped protrusion formed on the side of the head, with the front end of the arc-shaped protrusion open and the rear end connected to the interface of the sampling channel.

[0008] As a further technical solution, a first filter screen and a second filter screen are sequentially arranged inside the filter cavity. The first filter screen is made of stainless steel and is used to intercept large debris such as aquatic plants and branches. The second filter screen is a membrane filter material, and its pore size is selected according to the size distribution of the target eDNA particles.

[0009] As a further technical solution, the first and second filter screens are connected to the cavity via a snap-fit ​​sealing interface.

[0010] As a further technical solution, an electric stirring mechanism is provided in the mud mixing cavity.

[0011] As a further technical solution, the traction ring is connected to the drone via a rope.

[0012] As a further technical solution, the sampling body is made of metal material with a set mass.

[0013] As a further technical solution, the in-situ water rinsing device includes a cleaning solution storage tank for storing clean water (such as sterile deionized water). The cleaning solution storage tank is connected to a spraying device via pipeline. The spraying device includes multiple spray heads installed inside the sampling body. Before the drone arrives at the first sampling point, the spraying system is activated to pre-rinse the internal channels, using high-pressure water flow to flush the inner walls of the channels, removing any possible environmental residues and ensuring initial cleanliness. Simultaneously, a micro-pump and pipeline system are provided to deliver the cleaning solution to the spraying points.

[0014] As a further technical solution, spray heads are installed in the filtration cavity and the mud mixing cavity, with the nozzles facing the inner wall of the channel to ensure that the cleaning liquid can cover the entire flow surface. Finally, the waste liquid is collected and discharged to avoid mixing with the water sample.

[0015] Secondly, based on the aquatic organism eDNA mud sampler mounted on a drone, the present invention also provides a mud sampling method, as follows: Before the mud sampler is used for sampling, clean water from the in-situ water flushing device is pumped into the spraying device through the connecting pipe and transported to the spray head to clean the mud sampler. Then, the sample collection begins by being towed by a drone. During the drone towing process, the sample enters the sampling channel through the first sampling port at the bottom and the second sampling port on the side. First, it enters the first filter screen to intercept large impurities; then it enters the second filter screen to intercept biological particles and fine suspended matter carrying the target environmental DNA in the water. The sample enters the mud mixing cavity from the filtration cavity. Under the action of external force, the sample comes into contact with the electric stirring mechanism. The rotation of the electric stirring mechanism generates strong axial and radial circulation, which forces all solid particles and the liquid medium they carry to tumble, stir and mix fully in the cavity, and finally outputs a homogenized mud sample. After homogenization, the mud-water slurry is fed into the collection box under conveying pressure. The sample enters the pre-sterile, sealed sample collection chamber through a one-way valve. When the conveying is completed or the pressure is released, the valve automatically closes under the action of a spring, collecting the mud sample. The collection chamber is an independent module that can be aseptically disassembled in the laboratory, reducing contamination during sample transfer.

[0016] After collection is completed, the in-situ water flushing device is restarted to flush the sampling channel. The cleaning fluid flows through the spray head inside the sampling channel to wash away the residual mud adhering to the filter screen, the inner wall of the mud mixing cavity, and the surface of the partition. The flushing waste liquid is discharged through the waste liquid outlet.

[0017] This invention provides an aquatic organism eDNA sampler and method mounted on a drone, which has the following advantages compared with the prior art: 1. This eDNA mud sampler, by being equipped with a drone, solves the problem of the strong dependence of sampling on manpower and the environment. This device can safely and conveniently reach swamps, deep water areas, rapids, and remote waters with few people to conduct sampling, breaking through the geographical limitations of personnel and boats, greatly expanding the reach of eDNA monitoring, significantly improving sampling efficiency and spatial coverage, realizing the transformation from static "point sampling" to dynamic "line / area sampling", and using the drone platform to carry out continuous sampling, which can cover a wide water area in a single mission and obtain high-density, highly representative spatial distribution data. Specifically, the eDNA sludge sampler features a first sampling inlet on the bottom of its head. By controlling the inlet diameter, the UAV can deliver samples at a uniform speed while flying along a preset trajectory, achieving an innovative mode from static point sampling to dynamic line-surface sampling. A second sampling inlet is located on the side of the sampling head. In the event of unexpected changes in the UAV's flight attitude, such as tilting due to strong winds or turbulence, traditional single downward or forward inlets may briefly leave the water surface or allow air in, leading to sampling interruptions, insufficient sample volume, and consequently affecting sampling continuity and data quality. The dual-side inlet design ensures that at least one side remains in continuous contact with the water, maintaining stable sampling and effectively avoiding the aforementioned problems. This ensures sample representativeness and integrity under complex hydrological conditions, significantly improving the reliability and efficiency of field sampling. When the collected sample enters the sampling channel, the filter cavity, as the first step in the water intake process, can effectively perform solid-liquid separation to intercept particulate matter and eDNA attached to it in the water and remove large impurities. A rigid connecting rod is welded to the front end of the sampling head. Multiple traction rings are set at the front end of the rigid connecting rod. By selecting different tethering points, the direction and torque of the force on the sampler in the water can be changed, thereby actively controlling its pitch angle, roll angle or depth.

[0018] 2. The present invention incorporates filter screens of varying particle sizes within the filtration cavity, allowing water to pass through. A first filter screen, made of stainless steel, can be installed at the front end of the unit to intercept large debris such as aquatic plants and leaves. The rear end houses the second filtration layer, employing a membrane filter material with a specific pore size, selected based on the size distribution of the target eDNA particles. Furthermore, the filter cartridge shell and cavity utilize a snap-fit ​​sealing interface, facilitating filter screen replacement, ensuring leak-free operation, and enabling easy field replacement. Pre-filtration delays the clogging time of the second filter membrane, making it suitable for large-scale, long-distance continuous linear and surface sampling, resulting in a higher bioaccumulation of eDNA in the final collected samples.

[0019] 3. The mud mixing cavity of the present invention contains a micro-electric stirring mechanism that rotates at high speed under the drive of water flow and a micro-motor, mixing the mud sediment washed down from the filtration module to form a homogeneous sample. This solves the problem of uneven distribution of eDNA on the filter membrane after traditional filtration, providing a homogeneous sample for subsequent quantitative analysis and improving data repeatability. Furthermore, physical concentration can increase the eDNA abundance per unit volume of sample.

[0020] 4. A self-closing one-way valve is installed at the inlet between the mud mixing cavity and the collection cavity. When the concentrated mud arrives under pressure, the one-way valve opens; when the delivery is completed or the pressure disappears, the one-way valve automatically closes to form a physical seal.

[0021] 5. An in-situ water rinsing device is installed within the sampling channel. A cleaning solution tank is placed inside the drone fuselage or sampling head to store clean water (such as sterile deionized water). Before the drone reaches the first sampling point, the spray system is activated to pre-clean the sampling body, ensuring initial cleanliness. A micro-pump and piping system is also installed to deliver clean water to the spray points. Spray heads are installed upstream of the filter module and at the connections between modules, with the nozzles facing the inner wall of the channel to ensure the cleaning solution covers the entire flow surface. Finally, waste liquid is collected and discharged to prevent mixing with the water sample.

[0022] 6. This eDNA sampler eliminates cross-contamination between samples, ensuring the authenticity and reliability of eDNA data. Through the in-situ water rinsing device, it can automatically rinse the residual sample in the flow channel after each sampling and ensure that the sample is independently packaged, reducing the risk of false positive contamination caused by repeated use of the tool. Attached Figure Description

[0023] Figure 1 Schematic diagram of an aquatic organism eDNA sampler; Figure 2 This is a schematic diagram of the sampling channel; Icons: 1-Traction ring, 2-Rigid connecting rod, 3-Head, 4-Connecting pipe, 5-Spray head, 6-Cleaning fluid outlet, 7-Elastic buckle, 8-Metal cover, 9-Hinge, 10-Power pump, 11-In-situ water flushing device, 12-First sample inlet, 13-Second sample inlet, 14-Snap groove, 15-Sampling channel, 16-First filter screen, 17-Second filter screen, 18-Mud mixing cavity, 19-One-way valve, 20-Collection box, 21-Spiral stirring device. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0026] In the description of this invention, it should be noted that if terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, they are only for the convenience of describing this invention and simplifying the description, and are not intended to 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 this invention.

[0027] See Figure 1 , Figure 2 This embodiment discloses an aquatic organism eDNA sampling device mounted on a drone, including a drone, a traction ring mechanism connected to the drone, and a sampling body. By mounting an existing drone, the sampling body solves the problem of strong dependence on manpower and environment for sampling. At the same time, this device can safely and conveniently reach swamps, deep water areas, rapids, and remote waters with few people to conduct sampling, breaking through the geographical limitations of personnel and boats, greatly expanding the reach of eDNA monitoring, significantly improving sampling efficiency and spatial coverage, realizing the transition from static "point sampling" to dynamic "line / area sampling", and using a drone platform for continuous sampling, it can cover a wide water area in a single mission and obtain high-density, highly representative spatial distribution data.

[0028] The specific structure is as follows: The head 3 of the sampling body is streamlined and the rear is a rectangular sampling channel 15; and a metal cover 8 is provided on the top of the rectangular sampling channel 15 at the rear of the sampling body. The metal cover 8 is hinged to the sampling body and can be flipped up and opened in order to take out the collection box inside the sampling channel 15 and to clean the inside of the sampling body. During the sampling process, the metal cover 8 protects the inside of the sampling channel. The sampling head 3 is streamlined and torpedo-shaped to reduce its drag. The sampling head 1 is connected to the bottom of the drone via a traction rope, traction ring 1, and rigid connecting rod 2. When mounted on the drone, the water flow generates a relative velocity at the inlet, allowing the water to continuously flow through the internal filtration unit.

[0029] Furthermore, a rigid connecting rod 2 is welded to the front end of the sampling head 3. Multiple traction rings 1 are set at the front end of the rigid connecting rod 2. In this embodiment, four traction rings 1 are set. By selecting different mooring points, the direction and torque of the sampler in the water can be changed, thereby actively controlling its pitch angle, roll angle or depth.

[0030] Furthermore, the bottom surface of the sampling head 3 is provided with three first sampling ports 12. By controlling the diameter of the inlet, the UAV can inject samples at a constant speed when flying along the preset trajectory, realizing the innovative mode from static point sampling to dynamic line and surface sampling.

[0031] Furthermore, the sampling head has two secondary sampling ports 13 on its sides. In the event of unexpected changes in the drone's flight attitude, such as tilting due to strong winds or turbulence, traditional single downward or forward inlets may briefly leave the water surface or allow air to enter, leading to sampling interruptions, insufficient sample volume, and consequently affecting sampling continuity and data quality. The dual-side inlet design ensures that at least one side remains in continuous contact with the water, maintaining stable sampling and effectively avoiding the aforementioned problems. This ensures sample representativeness and integrity under complex hydrological conditions, significantly improving the reliability and efficiency of field sampling.

[0032] Furthermore, the first inlet 12 described above has an arc-shaped protrusion formed with the bottom surface of the head facing downwards. The front end of the arc-shaped protrusion is open, and the rear end is connected to the interface of the sampling channel. The first inlet 12 can be integrally formed with the sampling body, and the first inlet 12 can be directly processed on the sampling body. Furthermore, the aforementioned second inlet 13 has an arc-shaped protrusion formed on the side of the head, with the front end of the arc-shaped protrusion open and the rear end connected to the interface of the sampling channel; similarly, the second inlet 13 can also be integrally formed with the sampling body, and the second inlet 13 can be directly processed on the sampling body. By designing the shape and position of the first inlet 12 and the second inlet 13, and then coordinating with the movement of the UAV, the UAV can inject samples at a constant speed when flying along a preset trajectory, thus realizing a mode innovation from static point sampling to dynamic line and surface sampling.

[0033] Furthermore, the rear end of the sampling head 3 is a rectangular sampling channel 15, which is divided into a filtering cavity, a mud mixing cavity 18, and a collection cavity from front to back. A filter screen is installed in the filtering cavity, and a collection box 20 is installed in the collection cavity. A one-way valve 19 is installed on the partition between the mud mixing cavity 18 and the collection cavity, and an interface for connecting to the one-way valve 19 is provided on the collection box.

[0034] The filter cavity is provided with a first filter screen and a second filter screen in sequence. The first filter screen is made of stainless steel and is used to intercept large debris such as aquatic plants and branches. The second filter screen is a membrane filter material, and its pore size is selected according to the size distribution of the target eDNA particles.

[0035] Specifically, when the collected sample enters the sampling channel, the filtration cavity, as the first step in the water intake process, effectively performs solid-liquid separation to trap particulate matter and attached eDNA in the water, and remove large impurities. The filtration cavity is equipped with filter screens of different particle sizes to allow water to pass through. A first filter screen 16, made of stainless steel, can be installed at the front end of the filtration cavity to intercept large debris such as aquatic plants and branches; the second filter screen 17 is installed at the rear end, using a membrane filter material with a specific pore size. In this embodiment, a polycarbonate core-porous membrane is used, and its pore size is selected based on the size distribution of the target eDNA particles. The filter cartridge shell and the cavity body use a snap-fit ​​sealing interface for easy filter screen replacement, ensuring no leakage and facilitating field replacement. The first filter screen 16 can delay the clogging time of the second filter screen 17, making it suitable for large-scale, long-distance continuous linear and surface sampling, resulting in a higher bioaccumulation of eDNA in the final collected sample.

[0036] Furthermore, the aforementioned mud-mixing cavity 18 contains a micro-electric stirring mechanism that rotates at high speed under the drive of water flow and a micro-motor, mixing the mud sediment washed down from the filtration cavity to form a homogeneous sample. This solves the problem of uneven distribution of eDNA on the filter membrane after traditional filtration, providing a homogeneous sample for subsequent quantitative analysis and improving data repeatability. Moreover, physical concentration can increase the eDNA abundance per unit volume of sample; in this embodiment, the micro-electric stirring mechanism uses a spiral stirring device 21.

[0037] Furthermore, the aforementioned collection box 20 is a sealed, detachable collection chamber. The chamber is made of a chemically inert Teflon coating. It is connected to the outlet of a one-way valve 19 on the mud mixing cavity. When the concentrated mud arrives under pressure, the one-way valve 19 opens; when the delivery is complete or the pressure disappears, the one-way valve 19 automatically closes under the action of a spring, forming a physical seal. After collection, only the collection box 20 needs to be removed. The mud sample in the collection unit is a finished product, requiring no additional processing, making it convenient and efficient. The integrated design simplifies the assembly process and is more suitable for the rapid sampling needs in complex scenarios. At the same time, it avoids the sample residue problem at the joints of split structures and reduces loss and contamination during sample transfer.

[0038] Furthermore, an in-situ water flushing device 11 is installed inside the head 3. The in-situ water flushing device 11 includes a water storage tank, a power pump 10, and nozzles. The water storage tank is installed inside the drone fuselage or sampling head to store clean water (such as sterile deionized water). Before the drone arrives at the first sampling point, the in-situ water flushing device 11 is activated to pre-flush the internal flow channels to ensure initial cleanliness. At the same time, the power pump 10 and pipeline system are installed to deliver clean water to the spray points. Spray nozzles are installed upstream of the filter module and at the connection between modules, with the nozzles facing the inner wall of the channel to ensure that the cleaning water flow can cover the entire flow surface. Finally, the waste liquid is collected and discharged through the cleaning liquid outlet 6 to avoid mixing with the water sample. Compared to chemical disinfection methods, rinsing with clean water can avoid the inhibition or degradation of eDNA samples by chemical disinfectant residues; the system structure is simpler, requiring only a water storage tank, a micro pump, and pipelines, eliminating the need to handle corrosive chemical reagents; the rinsing waste liquid is environmentally harmless and can be directly discharged back into water bodies; clean water sources can be directly used during on-site operations, eliminating the need to carry additional disinfectant and reducing the complexity of operation preparation.

[0039] The working principle and data acquisition method are described below: Before the mud sampler takes samples, the clean water in the in-situ water flushing device 11 is pumped by the power pump 10 and enters the spraying device through the connecting pipe 4 and is transported to the spray head 5. The metal cover 8 ensures smooth operation inside the sampling channel 15. When the metal cover 8 is closed, the elastic buckle 7 can deform under external force until its hook-shaped part engages with the corresponding buckle groove 14.

[0040] During the drone towing process, the sample enters the sampling channel 15 through the bottom first inlet 12 and the side second inlet 13. First, it enters the first filter screen 16 to intercept large impurities; then it enters the second filter screen 17 to intercept biological particles and fine suspended matter carrying the target environmental DNA in the water.

[0041] Next, the sample enters the mud mixing cavity from the filtration cavity. Under the action of external force, the sample comes into contact with the spiral stirring device 21. The rotation of the spiral blades of the spiral stirring device 21 generates strong axial and radial circulation, which forces all solid particles and the carried liquid medium to fully roll, stir and mix in the cavity, and finally outputs the homogenized mud sample.

[0042] Finally, the homogenized mud-water slurry is fed into the collection box under conveying pressure. The sample enters the pre-sterile closed sample collection chamber through one-way valve 19. When the conveying is completed or the pressure is lost, the valve automatically closes under the action of the spring, collecting the mud sample. The collection chamber is an independent module that is easy to disassemble aseptically in the laboratory, reducing contamination during sample transfer.

[0043] After collection, the in-situ water rinsing device is activated to rinsing the sampling channel. The rinsing solution flows through the spray head 20 inside the sampling channel 15, washing away residual mud adhering to the filter screen, the inner wall of the mud mixing cavity, and the surface of the partition. The rinsing waste liquid is discharged through the waste liquid outlet. This physical rinsing method effectively reduces the risk of cross-contamination between samples and avoids potential interference from chemical disinfectants to the eDNA samples.

[0044] These connection methods may vary depending on the design of different drone mud samplers, but the above is a general description of the connection structure.

Claims

1. A mud sampler for aquatic organisms using eDNA mounted on a drone, characterized in that, Includes a drone and a sampling body; the sampling body is connected to the drone via a traction mechanism; The sampling body has a streamlined head and a rectangular sampling channel at the rear. A cover is provided at the top of the sampling channel, which is hinged to the sampling body and can be flipped up and opened. The bottom surface of the head has multiple first sampling ports, and the side surface of the head has a second sampling port. The first and second sampling ports are connected to the rectangular portion. The traction mechanism includes a rigid connecting rod at the tip of the sampling body head and multiple traction rings of different heights on the rigid connecting rod. An in-situ water flushing device is provided inside the head and is connected to the sampling channel through a pipeline. The sampling channel is divided into a filtration cavity, a mud mixing cavity, and a collection cavity from front to back. A filter screen is provided in the filtration cavity, and a collection box is provided in the collection cavity. A one-way valve is provided on the partition between the mud mixing cavity and the collection cavity, and an interface for connecting the one-way valve is provided on the collection box.

2. The aquatic organism eDNA sampler mounted on a drone as described in claim 1, characterized in that, The first injection port has an arc-shaped protrusion formed with the bottom surface of the head facing downwards. The front end of the arc-shaped protrusion is open, and the rear end is connected to the interface of the sampling channel.

3. The aquatic organism eDNA sampler mounted on a drone as described in claim 1, characterized in that, The second injection port is an arc-shaped protrusion formed on the side of the head, with the front end of the arc-shaped protrusion open and the rear end connected to the interface of the sampling channel.

4. The aquatic organism eDNA sampler mounted on a drone as described in claim 1, characterized in that, The filter cavity is provided with a first filter screen and a second filter screen in sequence. The first filter screen is made of stainless steel and is used to intercept large debris such as aquatic plants and branches. The second filter screen is a membrane filter material, and its pore size is selected according to the size distribution of the target eDNA particles.

5. The aquatic organism eDNA sampler mounted on a drone as described in claim 4, characterized in that, The first filter, the second filter, and the sampling channel are connected by a snap-fit ​​sealed interface.

6. The aquatic organism eDNA sampler mounted on a drone as described in claim 1, characterized in that, An electric stirring mechanism is installed inside the mud mixing cavity.

7. The aquatic organism eDNA sampler mounted on a drone as described in claim 1, characterized in that, The traction ring is connected to the drone via a rope.

8. The aquatic organism eDNA sampler mounted on a drone as described in claim 1, characterized in that, The sampling body is made of metal with a set mass.

9. The aquatic organism eDNA sampler mounted on a drone as described in claim 1, characterized in that, The in-situ water flushing device includes a cleaning fluid storage tank for storing clean water; the cleaning fluid storage tank is connected to a spraying device via a pipeline; the spraying device includes multiple spray heads disposed in the filter cavity and the mud mixing cavity, with the nozzles of the spray heads facing the inner wall of the channel.

10. The mud collection method of the aquatic organism eDNA mud sampler mounted on an unmanned aerial vehicle as described in any one of claims 1-9, characterized in that, as follows: Before the mud sampler is used for sampling, clean water from the in-situ water flushing device is pumped into the spraying device through the connecting pipe and transported to the spray head to clean the mud sampler. Then, the sample collection begins by being towed by a drone. During the drone towing process, the sample enters the sampling channel through the first sampling port at the bottom and the second sampling port on the side. First, it enters the first filter screen to intercept large impurities; then it enters the second filter screen to intercept biological particles and fine suspended matter carrying the target environmental DNA in the water. The sample enters the mud mixing cavity from the filtration cavity. Under the action of external force, the sample comes into contact with the electric stirring mechanism. The rotation of the electric stirring mechanism generates strong axial and radial circulation, which forces all solid particles and the liquid medium they carry to tumble, stir and mix fully in the cavity, and finally outputs a homogenized mud sample. After homogenization, the mud-water slurry is fed into the collection box under conveying pressure. The sample enters the pre-sterile closed sample collection chamber through a one-way valve. When the conveying is completed or the pressure is lost, the one-way valve automatically closes. Restart the in-situ water flushing device to flush the sampling channel. The cleaning fluid flows through the spray head inside the sampling channel to wash away the residual mud adhering to the filter screen, the inner wall of the mud mixing cavity, and the surface of the partition. The flushing waste liquid is discharged through the waste liquid outlet.

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