A light trapping method for collecting mangrove larvae and juveniles

Abstract

The invention belongs to the technical field of plankton collection in mangrove ecosystems, and discloses a light trapping method for collecting mangrove fry, comprising the following steps: obtaining geographical information of a mangrove sea area, and determining a trapping area according to the geographical information; measuring real-time depth information of the trapping area; setting a first trapping point and a second trapping point in the trapping area according to the real-time depth information; performing graded processing on the seawater depth in the area where the first trapping point is located to obtain a graded trapping depth; setting a graded trapping time period according to the graded trapping depth; setting a buffer time according to the geographical information, and establishing a temporary working area within the buffer time; starting the first trapping point and the second trapping point when the buffer time ends; and trapping fry in the mangrove sea area according to the graded trapping time period, that is, through this scheme design, the invention improves the collection efficiency of fry.

Description

Technical Field

[0001] The invention relates to the technical field of collecting plankton in mangrove ecosystems, and in particular to a light trapping method for collecting fry and juvenile fish in mangroves. Background Art

[0002] The early life history stage of fish refers to the stage starting from the fertilized egg, through the embryonic stage and larval stage, to the juvenile stage. The early life history stage is a stage of dynamic changes in morphology, behavior, physiology and ecological habits. The mortality rate at this stage is very high, up to 90% under natural conditions. The survival rate of fish in the early life history stage is the key to the size of the annual recruitment of fish, and is the main reason for changes in population size and age structure. By studying the characteristics of the early life history of fish and monitoring the population dynamics of early fish resources, effective data support can be provided for the management of fishery resources and the formulation of protection policies.

[0003] Mangroves are wetland woody plant communities that grow in the intertidal zones of tropical and subtropical coasts, are periodically flooded by seawater, and are composed mainly of evergreen trees or shrubs. Mangroves play an important role in maintaining biodiversity in coastal wetlands, protecting the coast, promoting siltation and land reclamation, fixing carbon sinks, purifying water quality, regulating climate, protecting aquatic germplasm resources, and ecotourism. They are one of the marine ecosystems with the highest biodiversity and productivity on Earth, and one of the ecosystems with the highest ecological service functions. They are known as "coastal guards" and "pioneers in land reclamation" and have important ecological, social and economic values. The criss-crossing roots of mangroves provide a natural shelter for fish and other offshore marine life, and the vegetation litter also provides sufficient food for the growth and reproduction of fish and other offshore marine life. They have become a place for many fry and young fish to feed and fatten, and have an important supporting function for offshore fisheries.

[0004] Fish larvae and juveniles are the key groups in the evaluation of mangrove ecological restoration effects. Effective collection of mangrove fish larvae and juveniles is the basis for conducting relevant research on the evaluation of mangrove ecological restoration effects. However, the complex tidal characteristics and the in-forest habitat with crisscrossing root systems make it difficult to carry out effective collection of fish larvae and juveniles in mangrove systems, especially for fish larvae and juveniles in in-forest habitats (root systems can easily damage nets). In mangrove waters, the existing small-scale collection devices lack an efficient collection method to match them, which in turn restricts the relevant research on mangrove fish larvae and hinders the protection and utilization of mangrove fishery resources. Summary of the invention

[0005] In view of this, the object of the present invention is to provide a light trapping method for collecting mangrove fish larvae and fry, aiming to improve the collection efficiency of the fish larvae and fry.

[0006] To achieve the above objectives, the present invention discloses the following solutions:

[0007] A light trapping method for collecting mangrove fry comprises the following steps:

[0008] S1: Obtaining geographical information of the mangrove sea area, and determining the trapping area according to the geographical information;

[0009] S2: measuring the real-time depth information of the trapping area;

[0010] S3: setting a first trapping point and a second trapping point in the trapping area according to the real-time depth information;

[0011] S4: classifying the seawater depth in the area where the first trapping point is located to obtain a graded trapping depth;

[0012] S5: setting a hierarchical trapping time period according to the hierarchical trapping depth;

[0013] S6: setting a buffer time according to the geographic information, and establishing a temporary work area within the buffer time;

[0014] S7: When the buffer time ends, starting the first trapping point and the second trapping point;

[0015] S8: trapping the fry and juvenile fish in the mangrove sea area according to the graded trapping time periods.

[0016] Preferably, the graded trapping depths include a first trapping depth, a second trapping depth and a third trapping depth.

[0017] Preferably, the hierarchical trapping period includes a first trapping period, a second trapping period and a third trapping period;

[0018] The first trapping period, the second trapping period and the third trapping period correspond to the first trapping depth, the second trapping depth and the third trapping depth respectively.

[0019] Preferably, setting the first trapping point and the second trapping point in the trapping area according to the real-time depth information comprises:

[0020] Acquiring illumination information of the light, and determining the underwater efficient illumination distance of the light according to the illumination information;

[0021] Within the underwater efficient irradiation distance, a first trapping point and a second trapping point are set in the trapping area according to the real-time depth information.

[0022] Preferably, the second trapping points are multiple and evenly distributed around the first trapping points.

[0023] Preferably, setting a buffer time according to the geographic information and establishing a temporary work area within the buffer time comprises:

[0024] Setting a buffer time according to the geographic information;

[0025] During the buffer time, a plurality of temporary working points are established outside the trapping area;

[0026] The plurality of temporary working points are evenly distributed and enclose a temporary working area.

[0027] Preferably, a trapping device is provided at the first trapping point, a first electric lamp is provided in the trapping device, and a strobe frequency of the first electric lamp is 50 to 80 Hz.

[0028] Preferably, a second electric lamp is provided at each of the plurality of the second trapping points, and a stroboscopic frequency of the second electric lamp is 0.125 to 0.25 Hz.

[0029] Preferably, the first trapping depth, the second trapping depth and the third trapping depth are 0.2 to 1 meter, 1 to 2 meters and 3 to 4 meters respectively.

[0030] Preferably, the first trapping period, the second trapping period and the third trapping period are respectively 15 to 30 minutes, 25 to 45 minutes and 30 to 60 minutes in length.

[0031] In summary, compared with the prior art, the present invention discloses a light trapping method for collecting mangrove fry, comprising the following steps: obtaining geographical information of a mangrove sea area, and determining a trapping area according to the geographical information; measuring real-time depth information of the trapping area; setting a first trapping point and a second trapping point in the trapping area according to the real-time depth information; performing graded processing on the seawater depth in the area where the first trapping point is located to obtain a graded trapping depth; setting a graded trapping time period according to the graded trapping depth; setting a buffer time according to the geographical information, and establishing a temporary working area within the buffer time; when the buffer time ends, starting the first trapping point and the second trapping point; trapping fry in the mangrove sea area according to the graded trapping time period, that is, through this design, the present invention improves the collection efficiency of fry, and the present invention has the beneficial technical effects of high trapping quality, high reliability, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 It is a schematic diagram of the implementation of a light trapping method for collecting mangrove fish larvae provided in this embodiment. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] In the description of the present invention, it should be noted that the terms "front", "rear", "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0036] In addition, the technical features involved in the different embodiments of the present invention described above can be combined with each other as long as they do not conflict with each other.

[0037] This embodiment provides a light trapping method for collecting mangrove fry, comprising the following specific steps:

[0038] S1: Obtain the geographical information of the mangrove sea area and determine the trapping area based on the geographical information;

[0039] In this embodiment, before collecting, the collectors can first obtain the geographical information of the mangrove sea area through multiple channels, such as by consulting mangrove-related books, browsing relevant journal articles, integrating relevant fishing logs and combining satellite remote sensing, artificial intelligence and visualization technologies, and then obtain the tidal characteristics of the mangrove sea area, mangrove vegetation and its root distribution and other geographical information, and finally determine the optimal trapping area based on these geographical information and the migration habits and routes of relevant fry and juveniles.

[0040] It should be noted that, in the specific implementation process, areas with less mangrove vegetation and deeper sea areas are usually the most preferred trapping areas. The geographical characteristics of this trapping area are: in the center of the trapping area, within a circle with a radius of 1.5 to 2.5 meters, there is no mangrove vegetation (or basically no mangrove vegetation), and it is less affected by the roots of nearby mangrove vegetation; outside the trapping area, the mangroves are relatively dense.

[0041] It should be further explained that the determination of the optimal trapping area reduces the impact of the mangrove sea area with crisscrossing root systems on the trapping device, thereby improving the efficiency and reliability of the collection of larvae and juveniles.

[0042] S2: Measure the real-time depth information of the trapping area;

[0043] In this embodiment, the collector uses an ultrasonic depth sounder to measure the trapping area in real time to obtain real-time depth information.

[0044] It should be noted that, in the specific implementation process, the ultrasonic depth sounder used in this embodiment is an echo sounder, which is mainly composed of two parts: an ultrasonic transducer and a measurement and control device. The ultrasonic transducer is used for ultrasonic emission and reception; the measurement and control device controls the instrument to transmit, receive and analyze the received data.

[0045] It should be further explained that, in some embodiments, the collectors may also use laser, pressure, or electromagnetic depth sounders, or mechanical depth sounding devices such as cables to measure the trapping area in real time to obtain real-time depth information of the trapping area.

[0046] S3: setting a first trapping point and a second trapping point in the trapping area according to the real-time depth information;

[0047] In this embodiment, this step includes: first, obtaining the illumination information of the light, and determining the underwater efficient illumination distance of the light based on the illumination information; second, within the underwater efficient illumination distance, setting the first trapping point and the second trapping point in the trapping area based on the real-time depth information.

[0048] It should be noted that most of the trapping lights on the market are LED lights, which will fail when their underwater illumination distance exceeds 10 meters. Generally speaking, their efficient underwater illumination distance is within 6 to 8 meters. Therefore, in this embodiment, the radial distance between the first trapping point and the second trapping point needs to be controlled within 6 to 8 meters. In the specific implementation process, the collectors can control the exact distance between the two according to the specific conditions of the optimal trapping area to obtain an efficient trapping effect.

[0049] S4: classifying the seawater depth in the area where the first trapping point is located to obtain a graded trapping depth;

[0050] In this embodiment, the graded trapping depths include a first trapping depth, a second trapping depth, and a third trapping depth.

[0051] It should be noted that the extreme depth of the mangrove sea area is usually within the range of 3 to 4 meters, and considering that different types of fry and juvenile fish are accustomed to moving at different depths, the first trapping depth, the second trapping depth and the third trapping depth can be set to 0.2 to 1 meter, 1 to 2 meters and 3 to 4 meters, respectively. In the present embodiment, they are preferably set to 0.6 meters, 1.5 meters and 3.5 meters, respectively. In some embodiments, the fry and juvenile fish collector can also set the depth of the area where the first trapping point is located to more levels of hierarchical trapping depths according to actual conditions. The depth range of each level and the accurate setting depth can be determined according to the actual conditions of the mangrove sea area.

[0052] It should be further explained that the setting of the graded trapping depth has achieved full coverage trapping of various types of larvae and juveniles in mangrove waters, thereby greatly improving the quality and efficiency of the collection work, and has promoted the research work on larvae and juveniles in mangrove waters and the protection and utilization of mangrove fishery resources.

[0053] S5: setting the hierarchical trapping time period according to the hierarchical trapping depth;

[0054] In this embodiment, the hierarchical trapping period includes a first trapping period, a second trapping period and a third trapping period, and the first trapping period, the second trapping period and the third trapping period correspond to a first trapping depth, a second trapping depth and a third trapping depth respectively.

[0055] It should be noted that in order to ensure the trapping efficiency of fry and fry, sufficient trapping time needs to be reserved for different trapping depths. According to the activity habits of fry and fry, the duration of the first trapping period, the second trapping period and the third trapping period is set to 15 to 30 minutes, 25 to 45 minutes and 30 to 60 minutes, respectively, and preferably set to 20 minutes, 35 minutes and 45 minutes, respectively.

[0056] It should be further explained that, in some embodiments, the fry collectors can also set the trapping time to more hierarchical trapping time periods according to the conditions of the mangrove sea area, and each trapping time period and the specific setting time can be determined according to the actual conditions of the mangrove sea area.

[0057] S6: Set a buffer time according to geographic information and establish a temporary work area within the buffer time;

[0058] In this embodiment, this step includes: setting a buffer time according to geographic information, establishing multiple temporary work points outside the trapping area during the buffer time, and the multiple temporary work points are evenly distributed and enclose a temporary work area.

[0059] It should be noted that, in the specific implementation process, how long the buffer time needs to be set, on the one hand, it is necessary to take into account the tidal characteristics of the mangrove sea area, on the other hand, it is necessary to take into account the activity habits of fry and fry. Generally speaking, the buffer time is usually set to about 30 minutes. In this embodiment, the buffer time can be set to 30 minutes. In some embodiments, the collector can set the buffer time shorter or longer according to the actual situation of the above two aspects.

[0060] It should be noted that, in the specific implementation process, the number of temporary work points can be set according to the geographical conditions of the mangrove sea area and the situation of the collection group. In this embodiment, 3 or 4 temporary work points can be set. In some embodiments, the collectors can set the number of temporary work points to more according to the above two conditions. However, considering that too many temporary work points will affect the effect of trapping, the number of temporary work points should generally not exceed 5.

[0061] It should be further explained that the reasonable setting of buffer time can not only avoid the influence of tides, but also reduce the impact of various tasks performed by collectors before the formal trapping work on larvae and juveniles, thereby improving the trapping efficiency. The setting of multiple temporary work points can, on the one hand, improve the convenience of various operations, and on the other hand, play a preventive role, that is, reduce the impact of the outside world on the trapping area, thereby indirectly improving the trapping efficiency of larvae and juveniles.

[0062] S7: When the buffer time ends, the first trapping point and the second trapping point are started;

[0063] During the specific implementation process, a trapping device is provided at the first trapping point, and a first electric lamp is provided in the trapping device. The stroboscopic frequency of the first electric lamp is 50 to 80 Hz. During the specific implementation process, the first electric lamp preferably uses an LED white electric lamp, and its stroboscopic frequency is preferably 50 Hz, that is, it flashes 100 times in one second.

[0064] In the specific implementation process, there are multiple second trapping points that are evenly distributed around the first trapping point. Second electric lamps are provided at multiple second trapping points. In this embodiment, 6 to 10 second trapping points can be provided, preferably 8 second trapping points. A second electric lamp is provided at each second trapping point. The strobe frequency of the second electric lamp is 0.125 to 0.25 Hz. The first electric lamp preferably uses an LED white electric lamp, and its strobe frequency is preferably 0.2 Hz, that is, it flashes once every 2.5 seconds.

[0065] It should be noted that the collectors at the temporary work point can control the multiple second lights and the first lights at the same depth through the control terminal to ensure the trapping effect of this embodiment.

[0066] It should be noted that the provision of multiple second trapping points and multiple second electric lamps expands the trapping range. This embodiment can attract all fry and juvenile fish around the trapping area to the trapping area, and then through the stroboscopic frequency difference between the first electric lamp and the second electric lamp, these fry and juvenile fish can be further attracted to the first trapping point, thereby greatly improving the collection efficiency of fry and juvenile fish.

[0067] S8: Trapping of fry and juvenile fish in mangrove waters according to the graded trapping period.

[0068] In the specific implementation process, trapping work is carried out at the first trapping depth, the second trapping depth and the third trapping depth in the first trapping period, the second trapping period and the third trapping period respectively.

[0069] After the above steps S1 to S8 are implemented, the implementation diagram is as shown in the attached Figure 1 shown.

[0070] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A light trapping method for collecting mangrove fry, It is characterized in that include: Obtaining geographical information of mangrove sea areas, and determining trapping areas according to the geographical information; Measuring real-time depth information of the trapping area; Setting a first trapping point and a second trapping point within the trapping area according to the real-time depth information; The step of setting a first trapping point and a second trapping point in the trapping area according to the real-time depth information comprises: Acquiring illumination information of the light, and determining the underwater efficient illumination distance of the light according to the illumination information; Within the underwater efficient irradiation distance, a first trapping point and a second trapping point are set in the trapping area according to the real-time depth information; the second trapping points are multiple and evenly distributed on the periphery of the first trapping point; a trapping device is provided at the first trapping point, a first electric lamp is provided in the trapping device, and the stroboscopic frequency of the first electric lamp is 50-80 Hz; a second electric lamp is provided at each of the multiple second trapping points, and the stroboscopic frequency of the second electric lamp is 0.125-0.25 Hz; The seawater depth in the area where the first trapping point is located is processed in a graded manner to obtain a graded trapping depth; the graded trapping depth includes a first trapping depth, a second trapping depth and a third trapping depth; the first trapping depth, the second trapping depth and the third trapping depth are 0.2 to 1 meter, 1 to 2 meters and 3 to 4 meters respectively; The hierarchical trapping time period is set according to the hierarchical trapping depth; the hierarchical trapping time period includes a first trapping time period, a second trapping time period and a third trapping time period; the first trapping time period, the second trapping time period and the third trapping time period correspond to the first trapping depth, the second trapping depth and the third trapping depth respectively; the durations of the first trapping time period, the second trapping time period and the third trapping time period are 15 to 30 minutes, 25 to 45 minutes and 30 to 60 minutes respectively; Setting a buffer time according to the geographic information and establishing a temporary work area within the buffer time; including: Setting a buffer time according to the geographic information; During the buffer time, a plurality of temporary working points are established outside the trapping area; A plurality of said temporary working points are evenly distributed and enclose a temporary working area; When the buffer time is over, starting the first trapping point and the second trapping point; The fry and juvenile fish in the mangrove sea area are trapped according to the graded trapping time periods.

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