A method for monitoring oyster biomass in an oyster seabed in an ocean ranch

Abstract

The present invention relates to a method for monitoring the biomass of oysters in a marine ranch oyster seabed, comprising the following steps: step 1, obtaining a water depth grid data set of a mixed seabed of oysters and artificial reefs; step 2, obtaining a water depth grid data set of an oyster seabed in a mixed seabed of oysters and artificial reefs; step 3, calculating the total volume of oysters in the oyster seabed; step 4, investigating the biomass per unit volume of oysters; step 5, calculating the total biomass of oysters. The method for monitoring the biomass of oysters in a marine ranch oyster seabed provided by the present invention can realize the safe and accurate operation of bottom trawl surveys under the seabed habitat with dense reef bodies, the rapid and effective identification of the coverage area of ​​artificial reefs, and the three-dimensional calculation of oyster biomass, so as to scientifically and efficiently monitor the biomass of oysters in the marine ranch oyster seabed, evaluate the repair and regeneration effect of the marine ranch on the oyster seabed, and provide technical support for the construction of marine ranches and the protection of oyster seabeds.

Description

Technical Field

[0001] The invention belongs to the technical field of marine ranch resource monitoring and relates to a method for monitoring oyster biomass in an oyster seabed of a marine ranch. Background Art

[0002] The oyster bed is a good habitat and marine gene bank for benthic organisms. It has ecological functions such as purifying water, coupling ecosystem energy flow, stabilizing the coastline and bottom, and promoting nutrient circulation. It plays an important role in maintaining the balance of the nearshore marine ecosystem.

[0003] Studies have shown that, affected by tidal flow fields, more than 96% of oyster larvae will break away from the initial reef during the breeding season and migrate to the surrounding sea areas with the ocean currents; the rocky artificial reefs in the marine ranch are good anchorages for oyster larvae, providing a suitable habitat for the growth and development of oysters, and achieving the restoration and regeneration of the oyster seabed. Therefore, it is necessary to conduct scientific and effective monitoring of the oyster biomass of the oyster seabed in the marine ranch to quantitatively verify and evaluate the restoration effect of the marine ranch on the oyster seabed, and provide technical support and scientific basis for the next step of marine ranch construction and oyster seabed restoration projects.

[0004] However, with the large-scale deployment of artificial reefs, the seabed of the marine ranch has been transformed into a highly heterogeneous benthic habitat with reef-like properties, with diverse types and significant differences. The traditional benthic biological survey methods of fixed-point sampling and local trawling have major problems:

[0005] 1) Oysters grow vertically on the seabed of the marine ranch, and the calculation of their biomass needs to consider the vertical distribution. Traditional survey methods can obtain surface data of oyster seabeds, but it is difficult to obtain three-dimensional data of the vertical distribution of oyster seabeds, and it is impossible to perform scientific and effective calculations of oyster biomass;

[0006] 2) In marine ranches, oyster seabeds are mostly concentrated around artificial reefs. The calculation of oyster biomass requires the elimination of interference from artificial reefs on the basis of effective identification. Conventional artificial reef identification usually uses the subjective judgment of experts. Although the spatial location of artificial reefs can be identified, their coverage area cannot be accurately calculated, and the efficiency is low, which brings difficulties to the calculation of oyster biomass;

[0007] 3) A large number of artificial reefs have been deployed in the marine ranch, and the reefs are densely distributed. The conventional extensive bottom trawling survey method is prone to running aground in the marine ranch, and navigation safety cannot be guaranteed. At the same time, the conventional bottom trawling survey method cannot accurately control the operating range within the oyster seabed, and the survey results may be biased. There are great difficulties in calculating the biomass per unit volume of oysters.

[0008] In summary, as a new form of fishery development in my country, marine ranching plays an important role in the restoration and regeneration of oyster beds. At the same time, the monitoring of oyster biomass in oyster beds in marine ranching faces new challenges, which need to be solved by new technical means. Summary of the invention

[0009] The purpose of the present invention is to overcome the shortcomings of traditional survey technology and provide a method for monitoring oyster biomass in a marine ranch oyster seabed. The method can achieve safe and accurate bottom trawl surveys in a reef-dense seabed habitat, rapid and effective identification of artificial reef coverage, and three-dimensional calculation of oyster biomass, so that the oyster biomass in the marine ranch oyster seabed can be calculated scientifically and efficiently, and the repair and regeneration effect of the marine ranch on the oyster seabed can be evaluated, providing technical support for the construction of marine ranches and the repair and regeneration of oyster seabeds.

[0010] The present invention solves the technical problem by adopting the following technical solutions:

[0011] Step 1: Obtain a water depth grid dataset of the mixed seabed of oysters and artificial reefs;

[0012] Step 2, obtaining a water depth grid dataset of the oyster seabed in the mixed seabed of oysters and artificial reefs;

[0013] Step 3, calculating the total volume of oysters in the oyster seabed;

[0014] Step 4, investigating the biomass per unit volume of oysters in the oyster seabed;

[0015] Step 5: Calculate the total biomass of oysters in the marine ranch oyster seabed.

[0016] The process of obtaining the water depth grid dataset of the mixed seabed of oysters and artificial reefs in step 1 includes:

[0017] a. Use differential GPS, multi-beam echo sounder and peripheral sensors to collect the depth data of the seabed of the marine ranch, form the marine ranch depth grid data set and multi-beam acoustic image, and the coordinate system is GCS_WGS_1984; GPS positioning information must be imported in real time during operation, with positioning accuracy ≤1m and acoustic data collection resolution ≤0.1m; peripheral sensors collect roll, pitch, bow, sound speed, tide level and draft error data and calibrate the depth data;

[0018] b. Use differential GPS and side-scan sonar to collect backscatter echo intensity data of the seabed of the marine ranch to form a side-scan sonar acoustic image of the marine ranch, with the coordinate system being GCS_WGS_1984; GPS positioning information must be imported in real time during operation, with a positioning accuracy of ≤1m and an acoustic data collection resolution of ≤0.1m; bottom tracking operations must be performed during the side-scan sonar image processing to remove interference from the water column;

[0019] c. Based on the multi-beam acoustic images and side-scan sonar acoustic images formed by a and b above, combined with expert knowledge judgment method, the seabed of the marine ranch is divided into different areas, and a box-type mud sampler is used to collect seabed samples in different areas to clarify the seabed types in different areas; the box opening area of ​​the box-type mud sampler is ≥ 0.05m 2 ; A GPS signal receiver is set above the box-type mud sampler to record the latitude and longitude of the sampling station;

[0020] d. Locate the spatial position of the mixed seabed of oysters and artificial reefs, and use software to draw a planar vector image of the mixed seabed of oysters and artificial reefs;

[0021] e. Overlay the surface vector image of the mixed seabed of oysters and artificial reefs with the marine ranch water depth raster dataset to extract the water depth raster dataset of the mixed seabed of oysters and artificial reefs.

[0022] The process of obtaining the water depth grid dataset of the oyster seabed in the mixed seabed of oysters and artificial reefs in step 2 includes:

[0023] a. Using the height difference between artificial reefs and oyster beds, the depth raster dataset of the mixed seabed of oysters and artificial reefs was spatially reclassified to determine the coverage of oyster beds in the mixed seabed of oysters and artificial reefs, thus forming a spatial range raster dataset of oyster beds. The natural break point classification method was used for reclassification, and the number of classifications was 2.

[0024] b. Overlay the spatial range raster dataset of the oyster seabed with the water depth raster dataset of the mixed seabed area of ​​oysters and artificial reefs obtained in step 1, remove the area covered by the artificial reefs, and obtain the water depth raster dataset of the oyster seabed.

[0025] The process of calculating the total volume of oysters in the oyster seabed in step 3 includes:

[0026] a. Set up points in the flat area around the oyster seabed, with the number of points ≥ 12, evenly distributed in the four directions of the oyster seabed: east, west, south, and north; record the water depth value of each point, calculate the average water depth value of all points, and use the average value as the water depth value of the bottom surface of the oyster seabed;

[0027] b. Convert the GCS_WGS_1984 coordinate system of the oyster seabed depth grid dataset obtained in step 2 into a projected coordinate system in meters;

[0028] c. Combine the water depth value of the bottom of the oyster seabed with the oyster seabed water depth grid dataset after changing to the projected coordinate system, and use the software to calculate the three-dimensional volume of the oyster seabed as the total volume of the oyster.

[0029] The process of investigating the biomass per unit volume of oysters in the oyster seabed in step 4 includes:

[0030] a. Randomly select oyster beds, use the positioning information provided by sub-meter differential GPS, and use the software that imports the spatial range raster dataset of the oyster beds in the marine ranch to navigate and conduct oyster surveys on the oyster beds. During the process, timely adjust and control the navigation path of the survey vessel to keep it within the range of the oyster beds and avoid collision with artificial reefs to ensure navigation safety. The trawl path length is ≥100m.

[0031] b. During navigation, use a rake-type bottom trawl to collect oyster samples from the oyster seabed. The length of the rake teeth should be ≥ 20 cm;

[0032] c. Place the oyster sample in a container of fixed capacity and calculate the biomass per unit volume of the oyster. The number of calculations shall be ≥ 3 and the arithmetic mean shall be taken;

[0033] The calculation of the total biomass of oysters in the marine ranch oyster seabed in step 5 refers to multiplying the total volume of oysters in the oyster seabed by the biomass per unit volume of oysters to obtain the total biomass of oysters in the oyster seabed, and the formula is as follows: B o =B uo *V o Among them, B o is the total biomass of oysters in the oyster seabed; B uo V is the biomass per unit volume of oysters in the oyster seabed; o is the total volume of oysters in the oyster bed.

[0034] The advantages and positive effects of the present invention are:

[0035] (1) The present invention successfully solves the problem that traditional survey methods cannot perform three-dimensional calculations on the oyster biomass of oyster seabeds in marine ranches: In the present invention, the acoustic equipment can identify and locate the spatial position and coverage area of ​​the oyster seabed, and obtain the thickness of the oyster seabed, thereby accurately calculating the three-dimensional volume of the oyster seabed, providing reliable basic data for the monitoring of oyster biomass, and improving the scientificity and accuracy of oyster biomass monitoring in the oyster seabed of marine ranches;

[0036] (2) Based on multi-beam acoustic data, the present invention successfully realizes the rapid identification of the coverage area of ​​artificial reefs in the mixed seabed of oysters and artificial reefs, overcomes the uncertainty of subjective identification by experts, improves the efficiency of identification, and makes the calculation of oyster biomass in the oyster seabed more accurate;

[0037] (3) By integrating the advantages of high-precision marine ranch acoustic images, sub-meter differential GPS and real-time navigation software, the present invention improves the traditional extensive bottom trawling survey method, greatly reduces the threat posed by the dense reefs in the marine ranch to the navigation safety of the survey ship, and improves the reliability and accuracy of the oyster seabed bottom trawling survey, making the calculation of the oyster biomass per unit volume more scientific. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A flow chart of a method for monitoring oyster biomass in an oyster seabed of a marine ranch according to the present invention;

[0039] Figure 2 This is the Tianjin Ocean Ranch water depth grid dataset according to the embodiment of the present invention;

[0040] Figure 3 This is a multi-beam acoustic image of Tianjin Ocean Ranch in an embodiment of the present invention;

[0041] Figure 4 This is a side-scan sonar acoustic image of Tianjin Ocean Ranch in an embodiment of the present invention;

[0042] Figure 5 The coordinate system of the Tianjin Ocean Ranch water depth grid dataset in the embodiment of the present invention;

[0043] Figure 6 This is the in-situ sample collection station of the Tianjin Ocean Ranch seabed in the embodiment of the present invention;

[0044] Figure 7 The corresponding relationship between the acoustic image features and the seabed type of Tianjin Ocean Ranch in the embodiment of the present invention;

[0045] Figure 8 The spatial range of the mixed seabed of oysters and artificial reefs in Tianjin Ocean Ranch in the embodiment of the present invention;

[0046] Fig. 9 The operating interface of the "Mask Extraction" tool of ArcGIS software in the embodiment of the present invention;

[0047] Fig.10 This is a seabed depth grid dataset of oysters and artificial reefs mixed with each other in an embodiment of the present invention;

[0048] Fig.11 It is a partial area of ​​the seabed water depth grid dataset of oysters and artificial reefs mixed in the embodiment of the present invention;

[0049] Fig.12 Tool interface and parameter settings for reclassifying spatial processing in an embodiment of the present invention;

[0050] Fig.13 The spatial range raster dataset of the oyster seabed according to the embodiment of the present invention;

[0051] Fig.14 The interface and parameter settings of the "Set to Empty Function" tool in the embodiment of the present invention;

[0052] Fig.15 The water depth grid dataset of the oyster seabed according to the embodiment of the present invention;

[0053] Fig.16 12 points and their water depths set in the flat area around the oyster seabed in the embodiment of the present invention;

[0054] Fig.17 The interface and parameter settings of the "Project Grid" tool in the embodiment of the present invention;

[0055] Fig.18 The interface and parameter settings of the "surface volume" tool of the embodiment of the present invention;

[0056] Fig.19 The embodiment of the present invention refers to the actual path of the oyster seabed trawl survey under the joint guidance of differential GPS, marine ranch oyster seabed spatial range raster dataset, and navigation software;

[0057] Fig. 20 The operation process of calculating the biomass per unit volume of oysters using a 20L container in an embodiment of the present invention;

[0058] Fig.21 These are the six subareas of the oyster seabed of Tianjin Ocean Ranch in an embodiment of the present invention. DETAILED DESCRIPTION

[0059] The present invention will be further described in detail below with reference to the accompanying drawings and through specific embodiments. The following embodiments are only illustrative and not restrictive, and the protection scope of the present invention cannot be limited thereto.

[0060] To verify the effectiveness of the method of the present invention, the embodiment of the present invention relies on the national marine ranch demonstration area in the Dashentang Sea Area of ​​Tianjin (Tianjin Marine Ranch) to monitor the oyster biomass of the oyster seabed in the Tianjin Marine Ranch. The specific implementation process is as follows:

[0061] Step 1. Obtain the water depth raster dataset of the mixed seabed of oysters and artificial reefs in Tianjin Ocean Ranch

[0062] 1)Reference Figure 2 , Figure 3 and Figure 5In this example, the 2024 multi-beam echo sounder of the American R2 Sonic company was used to detect the water depth of the Tianjin marine ranch area. Combined with peripheral sensors, the roll, pitch, bow pitch, draft, sound velocity, tide level and other errors of the survey ship during the operation were calibrated and calibrated to obtain accurate marine ranch water depth data, which was imported into ArcGIS 10.3 software for splicing and mosaicking to form a marine ranch water depth raster dataset ( Figure 2 ) and multibeam acoustic imaging ( Figure 3 ), whose coordinate system is GCS_WGS_1984( Figure 5 ); GPS positioning information is imported in real time during operation, with a positioning accuracy of ≤1m and an acoustic data collection resolution of 0.1m.

[0063] 2)Reference Figure 4 and Figure 5 , this embodiment uses Swedish Deep The company's DE340 side-scan sonar conducted an overall survey of the seabed of Tianjin Ocean Ranch; the equipment frequency is 340kHz and the resolution is 0.1m, which meets the needs of seabed type identification; the spatial positioning information comes from sub-meter differential GPS, and the positioning accuracy is ≤1m; the side-scan sonar data processing software uses DeepView FV 3.0 to convert the backscatter echo intensity data into side-scan sonar image brightness information. During the processing, bottom tracking operations are required to remove the interference of water columns; ArcGIS 10.3 software is used to stitch and mosaic the side-scan sonar data as a whole to form the Tianjin Ocean Ranch side-scan sonar acoustic image ( Figure 4 ), whose coordinate system is GCS_WGS_1984( Figure 5 );

[0064] 3)Reference Figure 6 and Figure 7 Based on the above multi-beam acoustic images and side-scan sonar acoustic images, the seabed of Tianjin Ocean Ranch was divided into different areas and 70 stations were set up ( Figure 6 ), using 0.05m 2 The box-type mud sampler collects in-situ seabed samples in different areas, and clarifies the correspondence between different image features and seabed types ( Figure 7 ), and divided the seabed types of Tianjin Ocean Ranch into six types: oysters, artificial reefs, silt, clam mud, oyster mud and crushed shellfish mud;

[0065] 4)Reference Figure 8Based on the correspondence between image features and seabed types, the spatial positions of various types of seabeds are located; since oyster seabeds are mostly distributed around artificial reefs, the two cannot be directly separated, so it is necessary to initially form a spatial range vector map of the mixed seabed of oysters and artificial reefs, and identify and remove artificial reefs in subsequent steps;

[0066] 5)Reference Fig. 9 and Fig.10 , using the ArcGIS software "Mask Extraction" tool ( Fig. 9 ), extract the water depth raster dataset of the mixed seabed of oysters and artificial reefs from the marine ranch water depth raster dataset according to the spatial range of the mixed seabed of oysters and artificial reefs ( Fig.10 ).

[0067] Step 2 Obtain the water depth raster dataset of the oyster seabed in the mixed seabed of oysters and artificial reefs

[0068] 1)Reference Fig.11 , Fig.12 and Fig.13 , taking a part of the seabed where oysters and artificial reefs are mixed as an example ( Fig.11 ), using the depth difference between artificial reefs and oyster beds, the depth raster dataset of the mixed seabed of oysters and artificial reefs was reclassified spatially ( Fig.12 ), select "Natural Breaks Classification" for classification method, select "2" for category, automatically calculate the water depth boundary value between artificial reefs and oyster seabed as "-4.73109951 meters", then set the area greater than the water depth boundary value as "NoData", and the area less than the water depth boundary value as "1", so as to obtain the coverage of oyster seabed in the mixed seabed of oysters and artificial reefs, and form the spatial range raster dataset of oyster seabed ( Fig.13 );

[0069] 2)Reference Fig.14 and Fig.15 , use the Set as Empty Function tool ( Fig.14 ), remove the artificial reefs from the mixed seabed of oysters and artificial reefs, and obtain the water depth raster dataset of the oyster seabed ( Fig.15 );

[0070] Step 3 Obtain the total volume of oysters in the oyster bed

[0071] 1)Reference Fig.16 , set up 12 points in the flat area around the oyster seabed, evenly distributed in the four directions of the oyster seabed; record the water depth value of each point, and calculate the average water depth of these 12 points to be -6.1 meters, which is the water depth value of the bottom of the oyster seabed;

[0072] 2)Reference Fig.17 , Use the "Project Raster" tool to convert the "GCS_WGS_1984" coordinate system of the oyster seabed depth raster dataset into the "CGCS2000_3_Degree_GK_CM_117E" projection coordinate system, with the unit being meters. The newly generated raster dataset is recorded as "oyster seabed depth_projection";

[0073] 3)Reference Fig.18 , use the "Surface Volume" tool, "Oyster Seabed Depth_Projection" as the input surface, set the reference plane to "ABOVE", the plane height to "-6.1", and the Z factor to "1". After running, the volume of the oyster seabed can be obtained as the volume of the oyster organism.

[0074] Step 4 Obtain the biomass per unit volume of oysters in the oyster seabed

[0075] 1)Reference Fig.19 , randomly select oyster beds, use differential GPS to provide positioning information, and accurately navigate based on software that imports the spatial range raster dataset of the marine ranch oyster beds. Adjust and control the navigation path of the survey ship in real time, and use bottom trawl to collect oyster samples from the oyster beds. The actual trawl path is as follows Fig.19 As shown, the length is 123.8 meters, within the oyster seabed and at a safe distance from the artificial reef;

[0076] 2)Reference Fig. 20 The collected oyster samples were placed in a 20L bucket and the biomass per unit volume of oysters was calculated to be 32.91 kg / m 3 ;

[0077] Step 5 Calculate the total biomass of oysters in the oyster bed

[0078] refer to Fig.21 The oyster seabed in Tianjin Marine Ranch is relatively scattered, so it is divided into 6 sub-areas for monitoring and calculation. The results are shown in Table 1. The total volume of oysters is 150727.3 cubic meters. When multiplied by the biomass per unit volume of oysters, the oyster biomass of the oyster seabed in Tianjin Marine Ranch is 4960.435443 tons.

[0079] Table 1 Calculation of oyster biomass on the seabed of Tianjin Ocean Ranch

[0080] Oyster bed sub-area Oyster volume (cubic meters) Oyster biomass (tons) 1 22634.5 744.901395 2 5045.6 166.050696 3 86971.2 2862.222192 4 4591.1 151.093101 5 4047 133.18677 6 27438.6 903.004326 total 150727.3 4960.435443

[0081] (1) The present invention successfully solves the problem that traditional survey methods cannot perform three-dimensional calculations on the oyster biomass of oyster seabeds in marine ranches: In the present invention, the acoustic equipment can identify and locate the spatial position and coverage area of ​​the oyster seabed, and obtain the thickness of the oyster seabed, thereby accurately calculating the three-dimensional volume of the oyster seabed, providing reliable basic data for the monitoring of oyster biomass, and improving the scientificity and accuracy of oyster biomass monitoring in the oyster seabed of marine ranches;

[0082] (2) Based on multi-beam acoustic data, the present invention successfully realizes the rapid identification of the coverage area of ​​artificial reefs in the mixed seabed of oysters and artificial reefs, overcomes the uncertainty of subjective identification by experts, improves the efficiency of identification, and makes the calculation of oyster biomass in the oyster seabed more accurate;

[0083] (3) By integrating the advantages of high-precision marine ranch acoustic images, sub-meter differential GPS and real-time navigation software, the present invention improves the traditional extensive bottom trawling survey method, greatly reduces the threat posed by the dense reefs in the marine ranch to the navigation safety of the survey ship, and improves the reliability and accuracy of the oyster seabed bottom trawling survey, making the calculation of the oyster biomass per unit volume more scientific.

[0084] Although the embodiments and drawings of the present invention are disclosed for illustrative purposes, those skilled in the art will appreciate that various substitutions, changes and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A method for monitoring oyster biomass in a marine ranch oyster seabed, characterized in that: The following steps are involved: Step 1: Obtain a water depth grid dataset of the mixed seabed of oysters and artificial reefs; Step 2, obtaining a water depth grid dataset of the oyster seabed in the mixed seabed of oysters and artificial reefs; Step 3, calculating the total volume of oysters in the oyster seabed; Step 4, investigating the biomass per unit volume of oysters in the oyster seabed; Step 5, calculating the total biomass of oysters in the marine ranch oyster seabed; The process of calculating the total volume of oysters in an oyster bed includes: a. Set up points in the flat area around the oyster seabed, with the number of points ≥ 12, evenly distributed in the four directions of the oyster seabed: east, west, south, and north; record the water depth value of each point, calculate the average water depth value of all points, and use the average value as the water depth value of the bottom surface of the oyster seabed; b. Convert the GCS_WGS_1984 coordinate system of the oyster seabed depth grid dataset obtained in step 2 into a projected coordinate system in meters; c. Combine the water depth value of the oyster seabed bottom with the oyster seabed water depth grid dataset after changing to the projected coordinate system, and use software to calculate the three-dimensional volume of the oyster seabed as the total volume of the oyster; The process of investigating the biomass per unit volume of oysters in the oyster bed comprises: a. Randomly select oyster beds, use the positioning information provided by sub-meter differential GPS, and use the software that imports the spatial range raster dataset of the oyster beds in the marine ranch to navigate and conduct oyster surveys on the oyster beds. During the process, timely adjust and control the navigation path of the survey vessel to keep it within the range of the oyster beds and avoid collision with artificial reefs to ensure navigation safety. The trawl path length is ≥100m. b. During navigation, use a rake-type bottom trawl to collect oyster samples from the oyster seabed. The length of the rake teeth should be ≥ 20 cm; c. Place the oyster sample in a container of fixed capacity and calculate the biomass per unit volume of the oyster. The number of calculations shall be ≥ 3 and the arithmetic mean shall be taken; The calculation of the total biomass of oysters in the marine ranch oyster seabed refers to multiplying the total volume of oysters in the oyster seabed by the biomass per unit volume of oysters to obtain the total biomass of oysters in the oyster seabed, and the formula is as follows: B o =B uo *V o Among them, B o is the total biomass of oysters in the oyster seabed; B uo V is the biomass per unit volume of oysters in the oyster seabed; o is the total volume of oysters in the oyster bed.

2. The method for monitoring oyster biomass in the seabed of an ocean ranch according to claim 1, characterized in that: The process of obtaining the water depth grid dataset of the mixed seabed of oysters and artificial reefs in step 1 includes: a. Use differential GPS, multi-beam echo sounder and peripheral sensors to collect the depth data of the seabed of the marine ranch, form the marine ranch depth grid data set and multi-beam acoustic image, the coordinate system is GCS_WGS_1984; import GPS positioning information in real time during operation, the positioning accuracy is ≤1m, and the acoustic data collection resolution is ≤0.1m; peripheral sensors collect roll, pitch, bow, sound speed, tide level and draft error data and calibrate the depth data; b. Use differential GPS and side-scan sonar to collect backscatter echo intensity data of the seabed of the marine ranch to form a side-scan sonar acoustic image of the marine ranch, with the coordinate system being GCS_WGS_1984; import GPS positioning information in real time during operation, with a positioning accuracy of ≤1m and an acoustic data collection resolution of ≤0.1m; perform bottom tracking during the side-scan sonar image processing to remove interference from the water column c. Based on the multi-beam acoustic images and side-scan sonar acoustic images formed by a and b above, combined with expert knowledge judgment method, the seabed of the marine ranch is divided into different areas, and seabed samples are collected in different areas using a box-type mud sampler to identify the seabed types in different areas; the box opening area of ​​the box-type mud sampler is ≥ 0.05m²; a GPS signal receiver is set above the box-type mud sampler to record the latitude and longitude of the sampling station; d. Locate the spatial position of the mixed seabed of oysters and artificial reefs, and use software to draw a planar vector image of the mixed seabed of oysters and artificial reefs; e. Overlay the surface vector image of the mixed seabed of oysters and artificial reefs with the marine ranch water depth raster dataset to extract the water depth raster dataset of the mixed seabed of oysters and artificial reefs.

3. The method for monitoring oyster biomass in the seabed of an ocean ranch according to claim 1, characterized in that: The process of obtaining the water depth grid dataset of the oyster seabed in the mixed seabed of oysters and artificial reefs described in step 2 includes: a. Using the height difference between artificial reefs and oyster seabeds, the water depth raster dataset of the mixed seabed of oysters and artificial reefs was spatially reclassified to determine the coverage of oyster seabeds in the mixed seabed of oysters and artificial reefs, and to form a spatial range raster dataset of oyster seabeds; the natural break point classification method was used for reclassification, and the number of classifications was 2; b. Overlay the spatial range raster dataset of the oyster seabed with the water depth raster dataset of the mixed seabed area of ​​oysters and artificial reefs obtained in step 1, remove the area covered by the artificial reefs, and obtain the water depth raster dataset of the oyster seabed.

Images