Underwater investigation system and underwater investigation method

Abstract

To improve work efficiency while suppressing the cost of underwater quadrat investigation.SOLUTION: An underwater investigation system 10 includes: a quadrat 16 for underwater use including a square frame 18, photographing means 20 which is capable of photographing at least a still image in underwater UW, and positioning means 22 for positioning the photographing means 20 for the square frame 18 at a position where the square frame 18 and the inside thereof can be photographed from above; a water-surface moving body 30 for moving the quadrat 16 for underwater use; suspending means 34 for suspending the quadrat 16 for underwater use from the water-surface moving body 30 into underwater UW; and remote control means 42 for operating the photographing means 20 remotely. This makes it possible to realize all works which need to be performed in the underwater UW by a water-surface or remote operation, by which operations by a diver are eliminated, a cost of quadrat investigation in the underwater UW can be suppressed, and work efficiency can be improved.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to underwater survey systems including underwater quadrats, and to underwater survey methods utilizing them. [Background technology]

[0002] Quadrats (see, for example, Patent Document 1) have traditionally been used to survey the coverage and population of eelgrass beds (also known as sandy mud seaweed beds), rocky reef seaweed beds, and benthic organisms. That is, just as quadrat surveys are used to survey terrestrial vegetation and animal populations, quadrats are also used by divers when conducting underwater surveys of oceans, lakes, etc. (see, for example, Patent Document 2). In such quadrat surveys conducted by divers, multiple survey lines are set underwater in the survey area using ropes and tape measures, and the survey is conducted at points on each of these survey lines, allowing the coordinates of the survey location to be ascertained. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-141866 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-119050 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional quadrat surveys using divers, such as those described above, require a large number of personnel and marine equipment, including divers, onboard assistants, work boats, and patrol boats, making them costly. In addition, the aforementioned ancillary work, such as setting up survey lines, is also required. Furthermore, when the survey area is large enough, the distance between survey lines must be large for work efficiency reasons. This means that the distance between survey lines becomes greater than the measurement interval along each line, which can lead to bias in measurement density and uncertainty in understanding the situation in the survey area. The present invention has been made in view of the above problems, and its object is to improve work efficiency while reducing the cost of underwater quadrat surveys. [Means for solving the problem]

[0005] (Aspects of the invention) The following embodiments of the present invention are examples of the configuration of the present invention, and are described in terms to facilitate understanding of the various configurations of the present invention. Each term does not limit the technical scope of the present invention, and while taking into consideration the best mode for carrying out the invention, some of the components of each term may be replaced or deleted, or other components may be added, and these may also be included in the technical scope of the present invention.

[0006] (1) A system for investigating underwater organisms, comprising: an underwater quadrat including a rectangular frame; a photographing means capable of taking at least still images underwater; a positioning means for positioning the photographing means relative to the rectangular frame so that the rectangular frame and its interior can be photographed from above when installed on the bottom of the water; a surface vehicle for moving the underwater quadrat; a hanging means for suspending the underwater quadrat from the surface vehicle so that it can be raised and lowered freely underwater; and a remote control means for remotely operating the photographing means.

[0007] The underwater survey system described in this section is for conducting underwater biological surveys and includes an underwater quadrant, a surface vehicle, a suspension means, and a remote control means. The underwater quadrant includes a rectangular frame, a photographing means, and a positioning means. The rectangular frame constitutes the main body of the underwater quadrant and is installed on the water bottom at the survey site during surveys. The photographing means is capable of taking at least still images underwater. The positioning means positions the photographing means relative to the rectangular frame, positioning the photographing means relative to the rectangular frame so that the rectangular frame and the interior of the rectangular frame can be photographed from above when installed on the water bottom. This allows the photographing means to accurately capture still images of the water bottom, including the rectangular frame.

[0008] The surface vehicle is for moving the underwater quadrant and includes a floating structure for floating on the water and a propulsion structure for moving on the water, and the suspension means is for suspending the underwater quadrant from the surface vehicle so that it can rise and fall freely in the water. The remote control means is for remotely operating the imaging means mounted on the underwater quadrant. Remote control here means operation of the remote control means away from the imaging means, which is submerged in the water, and the remote control means and the imaging means may be connected wirelessly and / or by wire.

[0009] With this configuration, the underwater quadrat is moved to a desired survey location by the surface vehicle, and at that location, the underwater quadrat is suspended from the surface vehicle by the suspension means and lowered until it is placed on the water bottom at the survey location. Then, by operating the imaging means via remote control means from a remote location, such as on the water or on land, still images of the rectangular frame placed on the water bottom at the survey location and its interior are captured. This means that all of the work required underwater, such as suspending the underwater quadrat underwater, placing the underwater quadrat on the water bottom at the survey location, and taking photographs with the imaging means, can be performed by surface or remote operation. This eliminates the need for divers, reduces the cost of underwater quadrat surveys, and improves work efficiency.

[0010] (2) In the above (1), the underwater survey system further includes a position measurement means for measuring the position of the surface vehicle. The underwater survey system described in this section further includes a position measurement means for measuring the position of the surface vehicle. The position of the surface vehicle is confirmed via this position measurement means, and the surface vehicle is guided to the survey location. This allows the underwater quadrat suspended from the surface vehicle to be accurately placed on the bottom of the water at the survey location, and the coordinates of the survey location where the surface vehicle and the underwater quadrat are located can be pinpointed and accurately determined. This eliminates the need to set up survey lines underwater, and allows the surface vehicle to be guided to survey lines and measurement points set on a map, enabling more efficient and cost-effective quadrat surveys. Furthermore, unlike conventional underwater quadrat surveys, there is no need to ensure a large distance between survey lines, eliminating bias in measurement density and enabling dense and accurate quadrat surveys.

[0011] (3) In the above item (1), the water vehicle is an unmanned mobile device that moves unmanned by autonomous navigation or remote control, and the suspension means is an underwater survey system that is operated by remote control. The underwater survey system described in this section is an unmanned mobile device in which the surface vehicle moves unmanned by autonomous navigation or remote control, and the suspension means is operated remotely. This eliminates the need to operate the surface vehicle on board or to operate the suspension means from on board; the surface vehicle moves autonomously or remotely, and the suspension means and imaging means are remotely operated from land, etc. This eliminates the need for personnel to board the surface vehicle, further improving work efficiency and reducing costs. Furthermore, by miniaturizing the surface vehicle consisting of an unmanned mobile device, it can easily be used to conduct quadrat surveys in locations that are difficult for personnel to access using ships, etc.

[0012] (4) In the above item (1), the water vehicle is a ship on which an operator boards, and the suspension means and the photographing means are operated by the operator on the ship, in an underwater investigation system. In the underwater survey system described in this section, the surface vehicle is a ship on which an operator boards, and the suspending means and camera means are operated by the operator on board the ship. Therefore, the operation of the ship that constitutes the surface vehicle, the suspension of the underwater quadrat from the ship, and the installation on the water bottom are performed on board, and photography by the camera means is also performed from on board via remote control means. As a result, the operator travels with the underwater quadrat by ship, and the work required for quadrat surveys can be performed at each survey point by operating only from on board.

[0013] (5) In the above (1), the suspension means includes a lifting device that automatically stops the lowering operation when the underwater quadrat hits the bottom. In the underwater survey system described in this section, the suspension means includes a lifting device for raising and lowering the underwater quadrat. This lifting device has a function to automatically stop the lowering operation when the underwater quadrat, which is being lowered underwater for installation on the water bottom, hits the bottom. This means that the underwater quadrat can be accurately installed on the water bottom at the survey site without the need for an operator to operate the suspension means while checking whether the underwater quadrat has hit the bottom.

[0014] (6) In the above item (1), the photographing means is capable of photographing video, or the underwater vehicle is equipped with video photographing means for photographing the bottom of the water, and the underwater survey system further includes a display means for displaying video photographed by the photographing means or the video photographing means. The underwater survey system described in this section is one in which the underwater quadrat's imaging means is capable of capturing video, or the surface vehicle is equipped with video imaging means for capturing video of the water bottom. It also includes display means for displaying video captured by the imaging means or video imaging means. This allows the operator to view video of the water bottom in real time on the display means, enabling the operator to install the underwater quadrat and set up any desired survey points while checking the water bottom conditions.

[0015] (7) In the underwater survey system according to the above item (1), the positioning means is a frame body attached to the rectangular frame so as to hold the photographing means directly above the rectangular frame. In the underwater survey system described in this section, the positioning means for the underwater quadrat is composed of a frame body, and this frame body is attached to the rectangular frame so as to hold the imaging means directly above the rectangular frame. This firmly positions the imaging means relative to the rectangular frame, allowing the imaging means to more accurately image the rectangular frame and its interior from above. Furthermore, because the positioning means is a frame body, the underwater quadrat is strong enough to resist distortion or damage even when moved up and down or when settled on the bottom.

[0016] (8) A method for investigating living organisms underwater, comprising: creating an underwater quadrat by positioning a rectangular frame installed on the bottom of the water and a photographing means capable of taking at least still images underwater in a position where it can photograph the frame and its interior from above; using a surface vehicle equipped with a position measurement means, the underwater quadrat is moved to a survey point while checking the position of the surface vehicle via the position measurement means; at the survey point, the underwater quadrat is suspended from the surface vehicle by a hanging means and allowed to settle on the bottom; remotely operating the shooting means to photograph the bottom of the water at the survey point together with the rectangular frame; and once the photographing is complete, the underwater quadrat is raised to the surface by the hanging means, and then the underwater quadrat is moved to the next survey point by the surface vehicle.

[0017] The underwater survey method described in this section involves conducting underwater biological surveys using a quadrat. First, an underwater quadrat is constructed, comprising a rectangular frame and a photographing device capable of capturing at least still images underwater. The photographing device is positioned relative to the rectangular frame so that the rectangular frame and its interior can be photographed from above while installed on the water bottom. The constructed underwater quadrat is then moved to a desired survey site by a surface vehicle equipped with a position measurement device, while the position of the surface vehicle is confirmed via the position measurement device. At the survey site, the underwater quadrat is suspended from the surface vehicle using a suspension device and lowered until it hits the bottom, placing the underwater quadrat on the water bottom at the survey site. The photographing device is then remotely operated from the water or on land to capture still images of the water bottom at the survey site, along with the rectangular frame. Once the photographing is complete, the underwater quadrat is lifted up to a shallow position on the water surface or in the water by the suspension means, and then moved to the next survey location by the surface vehicle.

[0018] With the above-described configuration, all tasks required underwater, such as suspending the underwater quadrat underwater, placing it on the bottom of the survey site, and taking photographs with the camera, can be performed by surface or remote operation, eliminating the need for divers. Additionally, by using a position measurement device, the underwater quadrat suspended from the surface vehicle can be accurately placed on the bottom of the survey site, and the coordinates of the survey site where the surface vehicle and the underwater quadrat are located can be pinpointed and accurately determined. This eliminates the need to set up survey lines underwater; quadrat surveys can be conducted by guiding the surface vehicle to survey lines and measurement points set on a map. This reduces the cost of underwater quadrat surveys while improving work efficiency. Furthermore, unlike conventional underwater quadrat surveys, there is no need for large distances between survey lines, eliminating bias in measurement density and enabling dense and accurate quadrat surveys. Furthermore, with the underwater quadrat configured as described above, a still image of the bottom of the water including the rectangular frame can be captured with high accuracy by the photographing means. [Effects of the Invention]

[0019] Because the present invention has the above-described configuration, it is possible to reduce the cost of underwater quadrat surveys and improve work efficiency. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a side view showing an example of the configuration of an underwater investigation system according to an embodiment of the present invention and a schematic representation of an investigation. [Figure 2] FIG. 2 is a perspective image diagram showing an example of the configuration of an underwater quadrat included in the underwater investigation system of FIG. 1. [Figure 3] FIG. 2 is a side view showing an example of a different configuration from that shown in FIG. 1 of an underwater investigation system according to an embodiment of the present invention. [Figure 4] FIG. 1 is a flowchart showing an example of a procedure for an underwater investigation method according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Here, detailed descriptions of parts that are the same as or corresponding to those in the prior art will be omitted, and the same reference numerals will be used throughout the drawings to indicate the same or corresponding parts. 1 is a schematic diagram of an underwater survey system 10 according to an embodiment of the present invention for surveying organisms on the bottom (BW) of the sea, lake, etc., and shows eelgrass 64 as an example of the organism to be surveyed, although this is not limited to eelgrass 64. As shown, the underwater survey system 10 according to the embodiment of the present invention includes an underwater quadrat 16, a surface vehicle 30, a suspension means 34, a remote control means 42, and a position measurement means 46.

[0022] The underwater quadrat 16 is used as a quadrat on the water bottom (BW) during biological surveys. As shown in FIG. 2, it includes a rectangular frame 18, a photographing device 20, and a positioning device 22. The rectangular frame 18 is a square or rectangular frame that is placed on the water bottom (BW) during biological surveys to survey the number and coverage of organisms within the rectangular frame 18. The rectangular frame 18 may be similar to a conventionally known quadrat or may be made of any material. The photographing device 20 is configured to capture at least still images in the underwater UW and may also capture video in addition to the still images. The photographing device 20 is remotely controlled by a remote control device 42 to capture still images, as described below. The photographing device 20 may be any underwater camera capable of capturing at least still images.

[0023] The positioning means 22 is used to position the imaging means 20 relative to the rectangular frame 18, and at this time, the imaging means 20 is positioned so that the rectangular frame 18 and its interior can be photographed from above. In this embodiment, a frame body 22A is used as the positioning means 22, and this frame body 22A is attached to the rectangular frame 18 so as to hold the imaging means 20 directly above the rectangular frame 18. The frame body 22A is formed of an appropriate material and shape capable of holding the imaging means 20. Note that FIG. 2 shows each component of the underwater quadrat 16 in a simplified form. Similarly, FIG. 1 and FIG. 3, which will be described later, also show each component of the underwater survey system 10, including the underwater quadrat 16, in a simplified form.

[0024] Returning to FIG. 1 , the surface vehicle 30 is used to move the underwater quadrant 16 and is equipped with a floating structure for floating on the water's surface and a propulsion structure for propelling the vehicle on the water's surface. In this embodiment, the surface vehicle 30 is comprised of an unmanned mobile device 30A that moves remotely and is controlled by an operator 60 via remote control means 42 from land L or elsewhere. The unmanned mobile device 30A may be any unmanned device, such as a radio-controlled boat or a water drone. The unmanned mobile device 30A may also be equipped with sensors and other devices for autonomous navigation. While FIG. 1 illustrates two of each of the surface vehicle 30 and other components mounted thereon, these are merely intended to illustrate the vehicle before and during the survey, as described below.

[0025] The suspending means 34 suspends the underwater quadrant 16 from the surface vehicle 30 so that it can be raised and lowered to the underwater UW. In this embodiment, the suspending means 34 includes a cable 36 and a lifting device 38. One end of the cable 36 is connected to the underwater quadrant 16, and the other end is reeled out and reeled in by the lifting device 38. The lifting device 38 is configured, for example, as a wire rope. The lifting device 38 is installed on the surface vehicle 30 and moves the underwater quadrant 16 up and down from the surface vehicle 30. As described above, the cable 36 is reeled out to lower the underwater quadrant 16 into the underwater UW, and the cable 36 is reeled in to raise the underwater quadrant 16. The lifting device 38 may have a function to automatically stop the lowering operation of the underwater quadrant 16 if it detects that the underwater quadrant 16 has reached the bottom BW while it is being lowered. The lifting device 38 of this embodiment is remotely controlled by a remote control means 42. The lifting device 38 may be any device such as an electric winch that fulfills the above-mentioned functions.

[0026] As described above, the remote control means 42 is used to remotely operate the imaging means 20, the surface vehicle 30, and the lifting device 38 from land L or the like. That is, the remote control means 42 remotely controls the imaging means 20 to take still images, the movement of the surface vehicle 30, and the lifting device 38 to lift and lower the underwater quadrant 16. In this case, the remote control means 42 may be configured to communicate wirelessly with the surface vehicle 30 and to communicate via wire to each operating mechanism within the surface vehicle 30. Furthermore, the remote control means 42 may be configured separately for each of the three remotely controlled objects: the imaging means 20, the surface vehicle 30, and the lifting device 38. Note that the location where the operator 60 operates the remote control means 42 is not limited to land L, and may be, for example, from a boat separate from the surface vehicle 30.

[0027] The position measurement means 46 is installed on the surface vehicle 30 and is used to measure the position of the surface vehicle 30, and by extension, to measure the position of the underwater quadrat 16 suspended from the surface vehicle 30 in the underwater UW. The position measurement means 46 may utilize, for example, a GPS, and acquires the position coordinates of the surface vehicle 30 and the underwater quadrat 16. The position data of the surface vehicle 30 and the underwater quadrat 16 measured by the position measurement means 46 can be confirmed by the operator 60, and for example, the remote control means 42 may be provided with a display function for the measured position data.

[0028] Next, Figure 3 shows the configuration of an underwater survey system 10' according to an embodiment of the present invention, which differs in part from the underwater survey system 10 according to the embodiment of the present invention shown in Figure 1. Here, the explanation will focus on the parts of underwater survey system 10' that are different from underwater survey system 10, and explanations of parts of underwater survey system 10' that are the same as or similar to underwater survey system 10 will be omitted or simplified. 3, an underwater survey system 10' according to an embodiment of the present invention includes an underwater quadrant 16, a surface vehicle 30, a suspension means 34, a remote control means 42, and a position measurement means 46, similar to the underwater survey system 10 of FIG. 1. Furthermore, the underwater survey system 10' includes a video capture means 50 and a display means 54.

[0029] The surface vehicle 30 of the underwater investigation system 10' is composed of a vessel 30B on which at least an operator 60 boards, and the vessel 30B is operated by the operator 60 or other personnel on board. For example, a small boat or a work boat may be used as this vessel 30B. The imaging means 20 of the underwater quadrant 16 and the lifting device 38 of the suspension means 34 are also operated by the operator 60 on board the vessel 30B. At this time, at least the imaging means 20 is remotely controlled via a remote control means 42 so that it can be operated from on board even when the underwater quadrant 16 is installed on the water bottom BW. Here, remote control of the imaging means 20 by the remote control means 42 includes both wireless operation from the remote control means 42 to the imaging means 20 and wired operation.

[0030] The video capture means 50 captures video of the water bottom BW and is attached to the surface vehicle 30 so as to capture video of the water bottom BW near the location where the underwater quadrat 16 is installed during the survey. Any camera capable of capturing video in the underwater UW can be used for the video capture means 50. Alternatively, or in addition to the video capture means 50, the underwater quadrat 16's imaging means 20 may capture video in addition to still images. The display means 54 displays video captured by the video capture means 50 and video captured by the imaging means 20. The display means 54 is installed on the surface vehicle 30 so as to display the video to the operator 60.

[0031] The underwater survey systems 10, 10' according to the embodiments of the present invention are not limited to the configurations shown in FIGS. 1 to 3 and can employ various configurations depending on the environment and conditions of the water area to be surveyed underwater. For example, the rectangular frame 18 and the frame body 22A constituting the positioning means 22 are not limited to the shapes shown in FIG. 2 and may have any shape as long as they fulfill their required functions. Furthermore, the suspension means 34 may include two cords 36 and two lifting devices 38 to separately raise and lower the rectangular frame 18 and the imaging means 20. In this case, the positioning means 22 may have any appropriate configuration that can position the imaging means 20 relative to the separately moving rectangular frame 18. Furthermore, the underwater survey system 10 shown in FIG. 1 may also include a video capture means 50 and a display means 54.

[0032] Next, an underwater survey method according to an embodiment of the present invention will be described, following the flow of the flowchart shown in FIG. 4, in which an underwater survey system 10, 10' according to an embodiment of the present invention, as shown in FIGS. 1 to 3, is used to survey organisms such as eelgrass 64 in an underwater UW. For the configuration of the underwater survey system 10, 10', please refer to FIGS. 1 to 3 as appropriate. Note that the flowchart shown in FIG. 4 shows an example of a procedural flow for explaining the underwater survey method according to an embodiment of the present invention. Therefore, the underwater survey method according to an embodiment of the present invention is not limited to this flowchart. For example, a flow in which some of the steps shown in FIG. 4 are deleted, modified, or added as appropriate may be used depending on the environment and conditions of the water area to be surveyed underwater.

[0033] S10 (Construction of underwater quadrat): Construct the underwater quadrat 16 as shown in Figure 2. That is, prepare the rectangular frame 18, the photographing means 20, and the frame body 22A (positioning means 22), and assemble the underwater quadrat 16 using appropriate means for the materials constituting each component. At this time, use the frame body 22A to position and attach the photographing means 20 relative to the rectangular frame 18 in a position that allows photographing the rectangular frame 18 installed on the bottom BW and its interior from above. S20 (Attaching the underwater quadrant): The underwater quadrant 16 prepared in S10 above is attached to the unmanned mobile device 30A or ship 30B that constitutes the surface vehicle 30. That is, the underwater quadrant 16 is connected to one end of the cord-like body 36 of the hanging means 34. Note that other components to be mounted on the surface vehicle 30 may be installed on the surface vehicle 30 in advance or at this time.

[0034] S30 (Move to Survey Location): The surface vehicle 30, to which the underwater quadrat 16 was attached in S20, is moved to the water area to be surveyed by appropriate means. In the underwater survey system 10 of FIG. 1, the operator 60 controls the unmanned mobile device 30A via the remote control means 42, and the unmanned mobile device 30A moves the underwater quadrat 16 to the pre-determined survey location. The operator 60 moves the unmanned mobile device 30A and the underwater quadrat 16 while checking their positions measured by the position measurement means 46 using the remote control means 42, etc. The underwater quadrat 16 is also moved while suspended by the suspension means 34 on the water surface near the water surface or in the underwater UW. This type of movement is represented by the unmanned mobile device 30A navigating from right to left in FIG. 1.

[0035] In contrast, in the underwater survey system 10' of Figure 3, an operator 60 or the like operates the vessel 30B, and moves the underwater quadrant 16 mounted on the vessel 30B to a predetermined survey point. At this time, the operator 60 or the like operating the vessel 30B moves the vessel 30B while checking the positions of the unmanned mobile device 30A and the underwater quadrant 16 measured by the position measurement means 46. The underwater quadrant 16 is moved to the survey point by being pulled up onto the vessel 30B and placed on the vessel 30B, or by being suspended by the suspension means 34 from a surface UW near the water surface or an underwater UW.

[0036] S40 (Underwater quadrant bottom landing): At the survey site to which the surface vehicle 30 was moved in S30, the operator 60 operates the lifting device 38 of the suspension means 34 via the remote control means 42 or directly on the ship 30B to pay out the cord 36. This causes the underwater quadrant 16 to be suspended from the surface vehicle 30 and sink in the water (UW), and the lifting device 38 continues to descend until the underwater quadrant 16 reaches the water bottom (BW) of the survey site. Then, once the underwater quadrant 16 has reached the bottom, the operator 60 operates the lifting device 38 to stop its descent. At this time, if the lifting device 38 has a function to detect the underwater quadrant 16 reaching the bottom and automatically stop, this function may be utilized. By performing the work up to this point, the underwater quadrat 16 is installed with the rectangular frame 18 facing downwards on the bottom BW of the survey area where organisms such as eelgrass 64 live, as in the underwater quadrat 16 on the left side of Figure 1. If the surface vehicle 30 is equipped with video recording means 50 or if the video recording means 20 also has a video recording function, the operator 60 can check the state of the bottom BW photographed by these means on the display means 54 while installing the underwater quadrat 16 or setting an appropriate survey point on the spot.

[0037] S50 (photographing survey location): The operator 60 remotely controls the photographing means 20 of the underwater quadrat 16 via the remote control means 42 to photograph a still image of the bottom BW of the survey location along with the rectangular frame 18. The still image taken here is used at an appropriate time for quadrat surveying the bottom BW of the survey area, and organisms such as eelgrass 64 within the rectangular frame 18 are surveyed, for example, for their coverage and population. S60 (Raising the underwater quadrant): The worker 60 operates the lifting device 38 of the hanging means 34 via the remote control means 42 or directly on the ship 30B to reel in the cord-like body 36. This raises the underwater quadrant 16 in the water UW and pulls it up near or onto the surface vehicle 30.

[0038] S70 (Survey Point Determination): Determine whether there are any survey points remaining in the water area being surveyed for which still images have not yet been taken of the bottom BW. If it is determined that there are any survey points remaining for which still images have not yet been taken (YES), return to S30 and move the underwater quadrat 16 using the surface vehicle 30 to any survey point for which image capture has not yet been completed. On the other hand, if there are no survey points remaining for which still images have not yet been taken and it is determined that the bottom BW of all survey points within the surveyed water area has been captured (NO), the explanation of the underwater survey method of this embodiment ends. In other words, the above S30 to S70 are repeatedly executed until image capture has been completed at all survey points within the surveyed water area.

[0039] According to the embodiment of the present invention configured as described above, the following effects can be obtained. That is, as shown in Figures 1 and 3, the underwater survey system 10, 10' according to the embodiment of the present invention is for conducting surveys of organisms in an underwater UW, and includes an underwater quadrant 16, a surface vehicle 30, a suspension means 34, and a remote control means 42. As shown in Figure 2, the underwater quadrant 16 includes a rectangular frame 18, a photographing means 20, and a positioning means 22. The rectangular frame 18 constitutes the main body of the underwater quadrant 16 and is installed on the water bottom BW at the survey site during surveys, and the photographing means 20 is capable of taking at least still images in the underwater UW.

[0040] The positioning means 22 positions the imaging means 20 relative to the rectangular frame 18, positioning the imaging means 20 relative to the rectangular frame 18 so that the rectangular frame 18 and the interior of the rectangular frame 18 can be photographed from above when installed on the water bottom BW. This allows the imaging means 20 to accurately capture still images of the water bottom BW, including the rectangular frame 18. Meanwhile, the surface vehicle 30 is used to move the underwater quadrant 16 and includes a floating structure for floating on the water and a propulsion structure for moving on the water. The suspending means 34 suspends the underwater quadrant 16 from the surface vehicle 30 to the underwater UW so that it can be raised and lowered. The remote control means 42 is used to remotely operate the imaging means 20 mounted on the underwater quadrant 16.

[0041] With this configuration, the underwater quadrat 16 can be moved to any desired survey location using the surface vehicle 30. At that location, the underwater quadrat 16 can be suspended from the surface vehicle 30 to the underwater UW using the suspension means 34 and lowered until it is installed on the bottom BW of the survey location. Then, by operating the imaging means 20 via the remote control means 42 from a remote location, such as on the water or on land L, still images of the rectangular frame 18 installed on the bottom BW of the survey location and its interior can be captured. This allows all tasks required for the underwater UW, such as suspending the underwater quadrat 16 to the underwater UW, installing the underwater quadrat 16 on the bottom BW of the survey location, and taking photographs with the imaging means 20, to be performed on the surface or remotely. This eliminates the need for divers to perform work, reducing the cost of quadrat surveys in the underwater UW and improving work efficiency.

[0042] The underwater survey system 10, 10' according to the embodiment of the present invention further includes a position measurement means 46 for measuring the position of the surface vehicle 30. The position of the surface vehicle 30 can be confirmed via this position measurement means 46, allowing the surface vehicle 30 to be guided to the survey location. This allows the underwater quadrat 16 suspended from the surface vehicle 30 to be accurately positioned on the water bottom BW at the survey location, and also allows the coordinates of the survey location where the surface vehicle 30 and the underwater quadrat 16 are located to be pinpointed and accurately determined. This eliminates the need to set up survey lines in the underwater UW, allowing the surface vehicle 30 to be guided to survey lines and measurement points set on a map, enabling more efficient and cost-effective quadrat surveys. Furthermore, unlike conventional underwater quadrat surveys, the distance between survey lines does not need to be large, eliminating bias in measurement density and enabling dense and accurate quadrat surveys.

[0043] As shown in FIG. 1, in the underwater survey system 10 according to the embodiment of the present invention, the surface vehicle 30 is an unmanned mobile device 30A that moves unmanned by remote control (or autonomous navigation), and the suspension means 34 is operated remotely. This eliminates the need to pilot the surface vehicle 30 on board or operate the suspension means 34 from on board. Instead, the surface vehicle 30 can be moved by remote control (or autonomous navigation), and the suspension means 34 and the imaging means 20 can be remotely operated from land L or elsewhere. This eliminates the need for personnel to board the surface vehicle 30, further improving work efficiency and reducing costs. Furthermore, by miniaturizing the surface vehicle 30, which is made up of the unmanned mobile device 30A, quadrat surveys can be easily conducted in locations that are difficult for personnel to access using ships or other vessels.

[0044] In contrast, as shown in Figure 3, in an underwater survey system 10' according to an embodiment of the present invention, the surface vehicle 30 is a ship 30B on which an operator 60 boards, and the suspending means 34 and the imaging means 20 are operated by the operator 60 on board the ship 30B. Therefore, the operation of the ship 30B constituting the surface vehicle 30, the suspension of the underwater quadrat 16 from the ship 30B, and the installation of the underwater quadrat 16 on the water bottom BW are performed on board, and imaging by the imaging means 20 is also performed from on board via remote control means 42. As a result, the operator 60 can move together with the underwater quadrat 16 on the ship 30B, and perform the work required for quadrat survey at each survey point by operating only from on board.

[0045] 1 and 3, in the underwater survey systems 10, 10' according to the embodiments of the present invention, the suspension means 34 includes a lifting device 38 for raising and lowering the underwater quadrant 16. The lifting device 38 may have a function to automatically stop the lowering operation when the underwater quadrant 16, which is being lowered by the underwater UW for installation on the water bottom BW, hits the bottom. This makes it possible to accurately install the underwater quadrant 16 on the water bottom BW at the survey site without the need for an operator 60 or the like to operate the suspension means 34 while checking whether the underwater quadrant 16 has hit the bottom.

[0046] Furthermore, the underwater survey systems 10, 10' according to the embodiments of the present invention may be configured so that the imaging means 20 of the underwater quadrat 16 is capable of capturing video, or the surface vehicle 30 is equipped with video capturing means 50 for capturing video of the water bottom BW. In this case, the system further includes a display means 54 for displaying video captured by the imaging means 20 or video capturing means 50. This allows video of the water bottom BW to be provided to the operator 60 in real time via the display means 54, allowing the operator 60 to install the underwater quadrat 16 and set up any desired survey points while checking the condition of the water bottom BW.

[0047] Additionally, in the underwater survey systems 10, 10' according to the embodiments of the present invention, as shown in Figure 2, the positioning means 22 of the underwater quadrat 16 is configured as a frame body 22A, and this frame body 22A is attached to the square frame 18 so as to hold the imaging means 20 directly above the square frame 18. This allows the imaging means 20 to be firmly positioned relative to the square frame 18, allowing the imaging means 20 to more accurately photograph the square frame 18 and its interior from above. Furthermore, since the positioning means 22 is a frame body 22A, the underwater quadrat 16 is strong enough to resist distortion or damage even when moved up and down or when it is landed on the bottom.

[0048] On the other hand, an underwater survey method according to an embodiment of the present invention uses a quadrat to survey living organisms in an underwater UW. As shown in Figure 4, first, an underwater quadrat 16 is fabricated, which includes a rectangular frame 18 and a photographing device 20 capable of capturing at least still images in the underwater UW (see S10). At this time, the photographing device 20 is positioned relative to the rectangular frame 18 so that it can photograph the rectangular frame 18 and its interior from above while it is installed on the water bottom BW, thereby fabricating the underwater quadrat 16. The fabricated underwater quadrat 16 is then moved to an arbitrary survey point by a surface vehicle 30 equipped with a position measuring device 46, while the position of the surface vehicle 30 is confirmed via the position measuring device 46 (see S30).

[0049] Furthermore, at the survey site, the underwater quadrat 16 is suspended from the surface vehicle 30 to the underwater UW by the suspension means 34, and the underwater quadrat 16 is lowered until it hits the bottom, placing the underwater quadrat 16 on the water bottom BW of the survey site (see S40). Then, the photographing means 20 is remotely operated from the water surface or land L to photograph a still image of the water bottom BW of the survey site together with the rectangular frame 18 (see S50). Once the photographing is complete, the underwater quadrat 16 is pulled up to a shallow position on the water surface or in the underwater UW by the suspension means 34 (see S60), and the underwater quadrat 16 is moved to the next survey site by the surface vehicle 30.

[0050] With the above configuration, all tasks that need to be performed in the underwater UW, such as suspending the underwater quadrant 16 from the underwater UW, setting it on the water bottom BW at the survey site, and taking photographs with the photographing means 20, can be performed by surface or remote operation, eliminating the need for work by a diver. In addition, by using the position measurement means 46, the underwater quadrant 16 suspended from the surface vehicle 30 can be accurately set on the water bottom BW at the survey site, and the coordinates of the survey site where the surface vehicle 30 and the underwater quadrant 16 are located can be pinpointed accurately.

[0051] This eliminates the need to set up survey lines in the underwater UW, and allows quadrat surveys to be conducted by guiding the surface vehicle 30 to the survey lines and measurement points set on a map. This reduces the cost of quadrat surveys in the underwater UW while improving work efficiency. Furthermore, unlike conventional underwater quadrat surveys, there is no need to set large distances between survey lines, so there is no bias in measurement density, and dense and accurate quadrat surveys can be achieved. Furthermore, the underwater quadrat 16 configured as described above allows for accurate still images of the water bottom BW, including the rectangular frame 18, to be captured by the imaging means 20. [Explanation of symbols]

[0052] 10, 10': underwater survey system, 16: underwater quadrat, 18: rectangular frame, 20: photographing means, 22: positioning means, 22A: frame body, 30: surface vehicle, 30A: unmanned mobile device, 30B: ship, 34: hanging means, 38: lifting device, 42: remote control means, 46: position measurement means, 50: video shooting means, 54: display means, 60: worker, UW: underwater, BW: bottom of water

Claims

1. A system for surveying underwater organisms, comprising: an underwater quadrat including a rectangular frame, a photographing means capable of taking at least still images underwater, and a positioning means for positioning the photographing means relative to the rectangular frame so that the rectangular frame and its interior can be photographed from above when installed on the bottom of the water; a surface vehicle for transporting the underwater quadrat; a suspending means for suspending the underwater quadrant from the water vehicle so that the quadrant can be raised and lowered into the water; and remote control means for remotely operating the imaging means.

2. 2. The underwater survey system according to claim 1, further comprising position measurement means for measuring the position of said surface vehicle.

3. The water vehicle is an unmanned mobile device that moves unmanned by autonomous navigation or remote control, 2. The underwater survey system of claim 1, wherein said suspension means is remotely operated.

4. the water vehicle is a vessel on which at least a worker boards, 2. The underwater survey system according to claim 1, wherein said suspension means and said photographing means are operated by said operator on said ship.

5. 2. The underwater survey system according to claim 1, wherein the suspension means includes a lifting device that automatically stops the lowering operation when the underwater quadrat hits the bottom.

6. The photographing means is capable of photographing video, or the underwater vehicle is equipped with a video photographing means for photographing the bottom of the water, 2. The underwater investigation system according to claim 1, further comprising display means for displaying the video captured by said photographing means or said video capturing means.

7. 2. The underwater survey system according to claim 1, wherein said positioning means is a frame body attached to said rectangular frame so as to hold said photographing means directly above said rectangular frame.

8. A research method for investigating organisms in water, comprising: a rectangular frame placed on the bottom of the water and a photographing means capable of taking at least still images underwater, the photographing means being positioned relative to the rectangular frame and installed in a position where it can photograph the inside of the rectangular frame from above, to prepare an underwater quadrat; a surface vehicle equipped with a position measurement means, the underwater quadrat is moved to a survey point while checking the position of the surface vehicle via the position measurement means; At the survey point, the underwater quadrat is suspended from the surface vehicle by a suspension means and allowed to land on the bottom; remotely controlling the photographing means to photograph the bottom of the water at the survey point together with the rectangular frame; After the photographing is completed, the underwater quadrat is lifted up by the suspension means, and then the underwater quadrat is moved to the next survey point by the surface vehicle.

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