Device and method for observing fish migration in small shallow river

Abstract

The invention discloses a method for observing fish migration in a small shallow river, and belongs to the field of fish behavior research. The method comprises the following two steps: 1) obtaining the position of a target fish in the river through a positioning device fixed in the river and a positioning method thereof; and 2) repeating the motion path and posture of the fish in the river by the optical sensing device of the fish according to the positioning data in the river, and recording the optical stimulation on the fish. The invention has the following beneficial effects: 1, an effective optical method and device are provided for obtaining migration and distribution of fishes in a shallow water transparent river reach; 2, an optical sensing device is adopted to directly acquire the external environment and optical characteristics of the eyes of the fish for the first time;

Description

Technical Field

[0001] The present invention relates to a device and method for observing fish migration in small shallow rivers. Specifically, it is a device and method for recording fish migration using a fish-eye-like camera after recording the fish movement trajectory, belonging to the field of fish behavior research. Background Art

[0002] The movement and migration of fish in natural water bodies have always been a field of concern for fish researchers. However, due to the shielding effect of water itself on electromagnetic signals and its opacity, it is often difficult to observe the movement of fish in their living water bodies. The commonly used method is to implant different types of tags on the fish body, and then use a detection device to detect them and analyze their movement patterns.

[0003] Defects of existing tags: Common implanted tags include acoustic tags and radio signal tags. The advantage of acoustic tags is that the distance is relatively far, and the position of fish in the water can be spatially located by setting multiple acoustic receiving devices on the shore. Radio signal tags require the setting of radio triggering and receiving devices in the river, and can often be detected only when close to the signal source.

[0004] Moreover, both of the above two tagging methods will cause harm to fish. The behavior of the tagged fish after returning to the river is often unpredictable, and sometimes it will cause stress reactions in fish and make it impossible to conduct normal observations and experiments.

[0005] Defects of direct video recording: Setting up a video recorder directly above a wide and shallow river is also a method to obtain fish behavior. However, due to the protective color on the back of fish and the specular reflection on the water surface, it is very difficult to identify fish during their swimming in the water, and it is also very difficult to track active fish with an ordinary camera.

[0006] Limitedness of data: The fish behavior trajectory data obtained by the existing tagging methods is only used to display the fish behavior trajectory, and cannot provide the surrounding environment information during the fish behavior process. Therefore, it is also impossible to restore the stimulating factors of fish behavior. Exploring the stimulating factors of fish migration behavior is a defect in the existing technology. In the existing technology, only the movement state of fish in space is captured, and the environmental perception of fish is not restored, while the perception of the surrounding environment by fish is the fundamental reason for stimulating fish behavior. Summary of the Invention

[0007] The technical problem to be solved by the present invention is: to propose a device and method for observing fish migration in small shallow rivers, and to obtain its environmental optical characteristics by simulating the fish optical sensing device.

[0008] Specifically, the present invention includes two steps:

[0009] 1. Obtain the position of the target fish in the river through a positioning device fixed in the river and its positioning method.

[0010] 2. Repeat the movement path and posture of the fish in the river according to the positioning data in the river by the optical sensing device of the fish.

[0011] Record the optical stimuli received by the fish.

[0012] The above-mentioned positioning device fixed in the river includes: an underwater camera and a spatial scale; arrange the underwater camera in the river, and arrange the position and angle of the underwater camera according to the spatial conditions of the river, so that the underwater camera can cover the entire river width as much as possible, and the spatial coordinates of each camera are accurately recorded; the spatial coordinates are preferably local coordinates; insert the spatial scale at the edge of the field of view of each camera, so that there are at least 2 spatial scales within the field of view of each camera.

[0013] The above-mentioned spatial scale is in the shape of a cross, including a horizontal bar and a vertical bar. The horizontal bar and the vertical bar are painted alternately with black and white paint at a width of 10 cm; use the spatial scale to mark the field of view of the camera in the image obtained by the camera; the lengths of the horizontal bar and the vertical bar are both not less than 1 m.

[0014] The above-mentioned arrangement of the position and angle of the underwater camera according to the spatial conditions of the river includes the following content: 1) On a river with relatively calm water flow, install an underwater camera bracket and position the camera below the lowest water level during the observation period; adjust the angle between the camera lens axis and the water surface to 30°. This angle is called the lens angle; the inventor found that in a wide and shallow river, when the lens angle is 30°, the fish in the camera image is most easily recognized.

[0015] The above-mentioned positioning method includes the following content: 1) After fixing the above-mentioned underwater camera and spatial scale, the underwater camera takes images of the spatial scale to calibrate the field of view of the camera, so that any object appearing in the camera can calculate its relative position relative to the scale and the underwater camera through the size of the scale; 2) Record the images of the fish during the migration process of the fish, and perform positioning on the fish based on the above-mentioned calibrated size for the obtained images, and calculate the position of the fish through the position of the scale and the position of the camera.

[0016] The above-mentioned river is a small shallow river, and the river water body has good light transmittance, and it is easy to obtain the swimming and distribution of fish through the underwater camera.

[0017] Install a navigation device on the top of the optical sensing device of the fish, repeat the movement path of the fish in the river according to the positioning data in the river, record the optical stimuli received by the fish and record the surrounding environment of the fish.

[0018] The above-mentioned optical sensing device includes: two single-lens underwater cameras and two camera brackets, and the above-mentioned two single-lens underwater cameras are fixed on the camera brackets;

[0019] The above-mentioned camera brackets include fixed bracket connection ends, bilateral camera connection ends, and tail adjustment locking ends;

[0020] The above-mentioned camera brackets include fixed bracket connection ends, which are connected to each other by a rotating shaft at the front and open and close around the rotating shaft;

[0021] A chute is opened horizontally on the camera bracket, and the single-lens underwater camera is fixed on the chute and slides along the chute;

[0022] The above-mentioned camera bracket is arc-shaped and can be replaced with different arcs according to needs;

[0023] Fix the two single-lens underwater cameras on the chute of the camera bracket, and adjust the included angle between the lens planes of the two underwater cameras to the included angle of the two eyes of the experimental object to form a double-camera group;

[0024] The double-camera group records the optical characteristics and images on the left and right sides respectively, and the recorded video content is closest to the actual situation observed by the experimental object.

[0025] The beneficial effects of the present invention are as follows:

[0026] 1. Provide an effective optical method and device for obtaining the migration and distribution of fish in shallow water transparent river sections;

[0027] 2. Use the optical sensing device to directly obtain the direct acquisition of the eyes of fish on the external environment and optical characteristics for the first time. Description of the Drawings

[0028] Figure 1 Schematic diagram of the planar layout of the underwater camera and the spatial scale in the embodiment of the present invention;

[0029] Figure 2 Schematic diagram of the layout of the underwater camera of the present invention;

[0030] Figure 3 Schematic diagram of the shape of the spatial scale of the present invention;

[0031] Figure 4 Schematic diagram of the spatial relationship among the underwater camera, the fish body trajectory, and the cross-section of the spatial scale of the present invention;

[0032] Figure 5 Exploded view of the optical sensing device C2 of the present invention;

[0033] Figure 6 Schematic diagram of the planar included angle between the optical sensing device C2 and the light source of the present invention. Detailed Embodiment

[0034] The present invention will be further described below in conjunction with the accompanying drawings.

[0035] Embodiment 1

[0036] In this embodiment, schizothoracids in a wide and shallow river are used as the observation object, and the following steps are adopted to achieve it:

[0037] 1. Obtain the position of the target fish in the river through the positioning device fixed in the river and its positioning method;

[0038] The above-mentioned positioning device fixed in the river includes: an underwater camera and a spatial scale; the underwater camera is arranged in the river, and the position and angle of the underwater camera are arranged according to the spatial conditions of the river, so that the underwater camera covers the entire river width as much as possible, and the spatial coordinates of each camera are accurately recorded; the spatial coordinates are preferably local coordinates; the spatial scale is inserted at the edge of the field of view of each camera, so that there are at least 2 spatial scales within the field of view of each camera; as Figure 1 shown, a total of 5 cameras and 6 spatial scales are arranged, and the coordinate data of each camera and spatial scale are accurately recorded.

[0039] The above-mentioned spatial scale is in the shape of a cross, including a horizontal bar and a vertical bar. The horizontal bar and the vertical bar are painted alternately in black and white paint at a width of 10 cm; the spatial scale is used to mark the field of view of the camera in the image obtained by the camera; the lengths of the horizontal bar and the vertical bar are both not less than 1 m;

[0040] The above-mentioned arrangement of the position and angle of the underwater camera according to the spatial conditions of the river includes the following contents: 1) On a river with relatively calm water flow, install an underwater camera bracket and position the camera below the lowest water level during the observation period; adjust the angle between the axis of the camera lens and the water surface to 30°. This angle is called the lens angle; the inventor found that in a wide and shallow river, when the lens angle is 30°, the fish in the camera image is most easily recognized.

[0041] The above-mentioned positioning method includes the following contents: 1) After fixing the above-mentioned underwater camera and spatial scale, the underwater camera takes images of the spatial scale to calibrate the field of view of the camera, so that any object appearing in the camera can calculate its relative position relative to the scale and the underwater camera through the size of the scale; 2) Record the images of the fish during the migration process of the fish, and perform positioning on the fish based on the above-mentioned calibrated size for the obtained images, and calculate the fish position through the scale position and the camera position.

[0042] Table 1 Coordinate Table of Underwater Camera and Scale

[0043]

[0044]

[0045] Table 2 Relationship Table between Underwater Camera and Scale

[0046]

[0047] The above-mentioned river is a small shallow river, and the river water body has good light transmittance, and it is easy to obtain the swimming trajectories of fish through an underwater camera.

[0048] 2. According to the swimming trajectory data in the river, the optical sensing device of the fish repeats its movement process according to the movement trajectory and posture, and records the optical stimuli received by the fish.

[0049] Install a navigation device on the top of the optical sensing device of the fish, use the observed fish trajectory as the planned route, manually drag the optical sensing device to move along the planned route, record the optical stimuli received by the fish and record the surrounding environment of the fish.

[0050] The above-mentioned optical sensing device includes: two single-lens underwater cameras C21, two camera brackets C22, and the two single-lens underwater cameras C21 are fixed on the camera brackets C22;

[0051] The above-mentioned camera bracket C22 includes a fixed bracket connection end, a bilateral camera connection end, and a tail adjustment locking end;

[0052] The above-mentioned camera bracket C22 includes a fixed bracket connection end, which are interconnected by a rotating shaft C24 at the front and open and close around the rotating shaft C24;

[0053] A chute C23 is opened transversely on the camera bracket C22, and the single-lens underwater camera C21 is fixed on the chute C23 and slides along the chute C23;

[0054] The above-mentioned camera bracket C22 is arc-shaped and can be replaced with different arcs according to needs;

[0055] Fix the two single-lens underwater cameras C21 on the chute C23 of the camera bracket C22, and adjust the included angle between the lens planes of the two underwater cameras C21 to the included angle of the two eyes of the experimental object to form a dual-camera group C2; in this embodiment, the binocular angle of the adult schizothoracin fish is 35°, and the included angle between the two cameras is adjusted to 35°.

[0056] The dual-camera group C2 records the optical characteristics and images on the left and right sides respectively, and the video content is closest to the actual situation observed by the experimental object;

[0057] The tail adjustment and locking end of the above-mentioned camera support is provided with two cross fixing slots C25, and the two cross fixing slots C25 are fixed together by a fixing bolt C26; when the relative positions of the two cross fixing slots C25 are adjusted, the included angle of the two side sliding slots C23 can be changed, that is, the included angle between the two single-lens underwater cameras C21 is changed.

[0058] Embodiment 2

[0059] In this embodiment, Schizopygopsis younghusbandi in a wide and shallow river is used as the observation object, and it is realized by the following steps:

[0060] 1. Obtain the position of the target fish in the river through the positioning device fixed in the river and its positioning method;

[0061] The above-mentioned positioning device fixed in the river includes: an underwater camera and a spatial scale; the underwater camera is arranged in the river, and the position and angle of the underwater camera are arranged according to the spatial situation of the river, so that the underwater camera can cover the entire river width as much as possible, and the spatial coordinates of each camera are accurately recorded; the spatial coordinates are preferably local coordinates; the spatial scale is inserted at the edge of the field of view of each camera, so that there are at least 2 spatial scales in the field of view of each camera; as Figure 1 As shown, a total of 5 cameras and 6 spatial scales are arranged, and the coordinate data of each camera and spatial scale are accurately recorded.

[0062] The above-mentioned spatial scale is in the shape of a cross, including a horizontal bar and a vertical bar. The horizontal bar and the vertical bar are both painted with black and white paint in a cross pattern with a width of 10 cm; the spatial scale is used to mark the field of view of the camera in the image obtained by the camera; the lengths of the horizontal bar and the vertical bar are both not less than 1 m;

[0063] The above-mentioned arrangement of the position and angle of the underwater camera according to the spatial situation of the river includes the following content: 1) On a river with relatively calm water flow, install an underwater camera support and position the camera below the lowest water level during the observation period; adjust the included angle between the camera lens axis and the water surface to 30°. This angle is called the lens angle; the inventor found that in a wide and shallow river, when the lens angle is 30°, the fish in the camera image is most easily recognized.

[0064] The above-mentioned positioning method includes the following content: 1) After fixing the above-mentioned underwater camera and spatial scale, the underwater camera takes an image of the spatial scale to calibrate the field of view of the camera, so that any object appearing in the camera can calculate its relative position with respect to the scale and the underwater camera through the size of the scale; 2) Record the images of the fish during the fish migration process, and perform positioning on the fish based on the above-mentioned calibrated size for the obtained images, and calculate the fish position through the scale position and the camera position.

[0065] Table 1 Coordinate Table of Underwater Camera and Scale

[0066]

[0067]

[0068] Table 2 Relationship Table of Underwater Camera and Scale

[0069]

[0070] The above-mentioned river is a small shallow river, and the river water body has good light transmittance, and the swimming trajectories of fish can be easily obtained through an underwater camera.

[0071] 2. According to the swimming trajectory data in the river, the optical sensing device of the fish repeats its movement process according to the movement trajectory and posture, and records the optical stimuli received by the fish.

[0072] Install a navigation device on the top of the optical sensing device of the fish. Take the observed fish trajectory as the planned route, and manually drag the optical sensing device to move along the planned route, record the optical stimuli received by the fish, and record the surrounding environment of the fish.

[0073] The above-mentioned optical sensing device includes: two single-lens underwater cameras C21, two camera brackets C22, and the above-mentioned two single-lens underwater cameras C21 are fixed on the camera brackets C22;

[0074] The above-mentioned camera bracket C22 includes a fixed bracket connection end, a bilateral camera connection end, and a tail adjustment locking end;

[0075] The above-mentioned camera bracket C22 includes a fixed bracket connection end, which are connected to each other by a rotating shaft C24 at the front and open and close around the rotating shaft C24;

[0076] A sliding groove C23 is opened transversely on the camera bracket C22, and the single-lens underwater camera C21 is fixed on the sliding groove C23 and slides along the sliding groove C23;

[0077] The above-mentioned camera bracket C22 is arc-shaped and can be replaced with different arcs according to needs;

[0078] Fix the two single-lens underwater cameras C21 on the sliding groove C23 of the camera bracket C22, and adjust the included angle between the lens planes of the two underwater cameras C21 to the included angle between the two eyes of the experimental object to form a dual-camera group C2; in this embodiment, the angle between the two eyes of the adult Schizopygopsis younghusbandi is 35°, and the included angle between the two cameras is adjusted to 35°.

[0079] The dual-camera group C2 records the optical characteristics and images on the left and right sides respectively, and the video content is closest to the actual situation observed by the experimental object;

[0080] The tail adjustment and locking end of the above camera bracket is provided with two cross fixing grooves C25, and the two cross fixing grooves C25 are fixed together by a fixing bolt C26; when the relative positions of the two cross fixing grooves C25 are adjusted, the included angle of the two side chutes C23 can be changed, that is, the included angle between the two single-lens underwater cameras C21 is changed. In this embodiment, the binocular included angle of Schizopygopsis younghusbandi waltoni is 152°.

[0081] Table 3 Analysis table of the relationship between the fish body and the light source

[0082]

Claims

1. A method for observing fish migration in small shallow rivers, characterized in that: It includes two steps: 1) Obtain the position of the target fish in the river through the positioning device fixed in the river and its positioning method; 2) Repeat the movement path and posture of the fish in the river according to the positioning data in the river by the optical sensing device of the fish, and record the optical stimuli received by the fish.

2. The method for observing fish migration in small shallow rivers according to claim 1, wherein: The positioning device fixed in the river includes: an underwater camera and a spatial scale; the underwater camera is arranged in the river, and the position and angle of the underwater camera are arranged according to the spatial conditions of the river, so that the underwater camera covers the entire river width and records the spatial coordinates of each camera; the spatial scale is inserted at the edge of the field of view of each camera, so that there are at least 2 spatial scales in the field of view of each camera; The spatial coordinates are preferably local coordinates.

3. A method for observing fish migration in small shallow rivers according to claim 2, characterized in that: The spatial scale is in the shape of a cross, including a crossbar and a vertical bar. The crossbar and the vertical bar are both painted in black and white paint in a cross pattern with a width of 10 cm; the spatial scale is used to mark the field of view of the camera in the image obtained by the camera; the lengths of the crossbar and the vertical bar are both not less than 1 m.

4. A method for observing fish migration in small shallow rivers according to claim 2, characterized in that: The arrangement of the position and angle of the underwater camera according to the spatial conditions of the river includes the following: 1) On a river with relatively calm water flow, install an underwater camera bracket and position the camera below the lowest water level during the observation period; adjust the angle between the camera lens axis and the water surface to 30°. This angle is called the lens angle.

5. A method for observing fish migration in small shallow rivers according to claim 1, characterized in that: The positioning method includes the following: 1) After fixing the above underwater camera and spatial scale, the underwater camera takes images of the spatial scale and calibrates the field of view of the camera, so that the relative position of any object appearing in the camera relative to the scale and the underwater camera can be calculated through the size of the scale; 2) Record the images of the fish during the migration process of the fish, and position the fish based on the above calibrated size for the obtained images, and calculate the fish position through the scale position and the camera position.

6. A method for observing fish migration in small shallow rivers according to claim 1, characterized in that: Repeating the movement path of the fish in the river by the optical sensing device of the fish according to the positioning data in the river means installing a navigation device on the top of the optical sensing device of the fish, repeating the movement path of the fish in the river according to the positioning data in the river, recording the optical stimuli received by the fish and recording the surrounding environment of the fish.

7. A method for observing fish migration in small shallow rivers according to claim 1, characterized in that: The optical sensing device includes: two single-lens underwater cameras and two camera brackets, and the two single-lens underwater cameras are fixed on the camera brackets; The camera bracket includes a fixed bracket connection end, a bilateral camera connection end, and a tail adjustment locking end; The camera bracket includes a fixed bracket connection end, which is connected to each other by a rotating shaft at the front and opens and closes around the rotating shaft; A chute is opened laterally on the camera bracket, and the single-lens underwater camera is fixed on the chute and slides along the chute; The camera bracket is arc-shaped and can be replaced with different arcs according to needs; Fix the two single-lens underwater cameras on the chute of the camera bracket, and adjust the included angle between the lens planes of the two underwater cameras to the included angle of the two eyes of the experimental object to form a double-camera group; The dual camera units respectively record the optical features and images on the left and right sides, and the recorded content is closest to what the experimental subject actually observes.

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