Enhancement release type screening method, system and device based on community structure stability

Abstract

The invention relates to a community structure stability-based enhancement and release variety screening method, system and device, and belongs to the technical field of marine fishery resource enhancement and release, and the method comprises the steps of target sea area fishery resource investigation, community structure stability analysis, candidate species preliminary screening, candidate species comprehensive evaluation and enhancement and release variety determination. The ABC curve method system is applied to enhancement and release variety screening for the first time, the community structure stability serves as a core ecological element, the defect of suitability of an existing selection standard multi-focus population is overcome, species having a key effect on maintaining the community structure stability can be screened out, and the selection accuracy is improved. And the selection of enhancement and release types better meets the overall balance requirement of an ecological system.

Description

A method, system, and apparatus for screening species for stock enhancement and release based on community structure stability. Technical Field

[0001] This invention belongs to the field of marine fishery resource enhancement and release technology, specifically relating to a method, system, and device for screening species for enhancement and release based on community structure stability. Background Technology

[0002] With the intensification of human activities such as overfishing, water pollution, and industrial development, global marine fishery resources are facing a severe decline crisis. Marine stock enhancement, as an effective means of restoring fishery resources in the short term, has been widely used worldwide. Large-scale stock enhancement began in the late 19th century, and its large-scale implementation was driven by the rapid development of mariculture, tagging technology, and genetic technology in the late 20th century.

[0003] Currently, the selection of species for stock enhancement and release mainly focuses on the suitability of the population itself, prioritizing native species with mature aquaculture techniques, low aquaculture costs, fast growth rates, high economic value, and short food chains. However, approximately 200 species selected for stock enhancement and release have failed to achieve the expected results. The main reason is that the existing selection criteria lack consideration of community-level ecological factors: on the one hand, many marine species are difficult to survive after the larval stage, and their numbers cannot meet the needs of stock enhancement and release; on the other hand, there is a lack of understanding of the population dynamics of the released species, and a lack of relevant qualitative assessment tools, resulting in poor release effects.

[0004] Due to the lack of unified standards and quantitative assessment tools in current technologies, it remains unclear how to guide the selection of species for stock enhancement and release from a community ecology perspective. Current ecological factors for species selection are mainly based on interspecific feeding interactions, intraspecific adaptability of wild and cultured populations, and release density. This approach fails to adequately consider the contribution of species to community structural stability, resulting in some stock enhancement and release activities not only failing to achieve resource restoration goals but also negatively impacting ecosystem balance. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for screening species for stock enhancement and release based on community structure stability. This method takes the ABC curve method as its core and combines multiple ecological and practical application factors to scientifically screen species for stock enhancement and release, thereby improving the ecological and economic benefits of stock enhancement and release.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a method for screening species for stock enhancement and release based on community structure stability, the method comprising: surveying fishery resources in the target sea area, analyzing community structure stability, preliminary screening of candidate species, comprehensive evaluation of candidate species, and determining the species for stock enhancement and release; the surveying of fishery resources in the target sea area includes statistically analyzing the biomass and abundance of each species in the target sea area; furthermore, the survey stations need to cover different water depths and habitat types; the survey is conducted in spring and summer for at least 3 consecutive years, with the spring survey time being May, when most marine organisms are in their breeding season, and fishing activities have a certain impact on the structure of swimming organism communities; the summer survey time is August, which is after the juveniles have matured and is within the summer fishing moratorium, thus eliminating interference from fishing activities and the bias of small fish on the analysis results.

[0007] The community structure stability analysis included: estimating fishery resources using the sea area sweep method, and analyzing the structural stability of swimming biological communities and fish communities using the ABC curve method and W statistic; furthermore, the W statistic was calculated using the formula W = ∑(B i -A i ) / s, Bi is the cumulative percentage of biomass, A i 's' represents the cumulative percentage of abundance, and 's' represents the number of species captured. The x-axis of the ABC curve represents the number of species, and the y-axis represents the cumulative percentage of species biomass or abundance. When the biomass curve is above the abundance curve, the W statistic is positive, indicating a stable community structure with minimal disturbance. When the biomass curve intersects the abundance curve, it indicates a relatively stable community structure. When the biomass curve is below the abundance curve, the W statistic is negative, indicating a severely disturbed community structure. By comparing the ABC curve morphology and W statistic values ​​of swimming biological communities and fish communities, more stable community types can be screened.

[0008] The initial screening of candidate species, based on the community structure stability analysis results, selects species with a high biomass proportion and significant contributions to community stability as candidate species. Furthermore, priority is given to benthic species, as the biological disturbance activities of benthic organisms, such as feeding, crawling, predator avoidance, burrowing, and habitat construction, can promote the release of nitrogen and phosphorus from sediments, enhance microbial metabolic activity, transfer energy through the food chain, and maintain community structure stability.

[0009] The comprehensive evaluation of candidate species includes: assessing candidate species based on the maturity of artificial breeding technology, complexity of trophic relationships, energy flow contribution, and recapture rate; furthermore, prioritizing species with mature artificial breeding technology and the ability to be cultivated on a large scale to ensure the quantity and quality of released seedlings; prioritizing species with diverse predators and multiple food sources, as complex trophic relationships can enhance ecosystem stability; prioritizing species that can accelerate the transfer of excess energy from specific trophic levels to energy-deficient trophic levels; and prioritizing species with high recapture rates and good population replenishment effects in the natural environment.

[0010] The determination of the species for stock enhancement and release is as follows: Based on the comprehensive evaluation results of candidate species, candidate species with mature artificial seedling technology, complex trophic relationships, ability to promote energy cycling, and high recapture rate are selected as the final species for stock enhancement and release; if there are multiple species that meet the conditions, a combination of multiple species is selected for release based on the characteristics of the target marine ecosystem.

[0011] A system for screening species for stock enhancement and release based on community structure stability is disclosed. The system includes a target sea area fisheries resource survey module, a community structure stability analysis module, a candidate species initial screening module, a candidate species comprehensive evaluation module, and a module for determining stock enhancement and release species. The target sea area fisheries resource survey module inputs survey results from the target sea area, calculates the biomass and abundance of each species in the target sea area, and inputs this data into the community structure stability analysis module. The community structure stability analysis module estimates fisheries resources using the sea area survey method and applies the ABC curve method and W... Statistical analysis is performed on the structural stability of swimming and fish communities. The results are then input into a candidate species screening module. Based on the community structural stability analysis, this module selects species with high biomass proportions and significant contributions to community stability as candidate species. These results are then input into a comprehensive candidate species evaluation module. This module evaluates candidate species based on the input results, considering factors such as the maturity of artificial breeding technology, complexity of trophic relationships, energy flow contribution, and recapture rate. The results are then input into a species determination module. This module selects candidate species with mature artificial breeding technology, complex trophic relationships, the ability to promote energy cycling, and high recapture rates as the final species for stock enhancement. If multiple species meet the criteria, a combination of species is selected for release based on the characteristics of the target marine ecosystem, and the final result is output.

[0012] The present invention also provides a species selection device for stock enhancement and release based on community structure stability, wherein the device is equipped with the aforementioned selection system.

[0013] The beneficial effects of this invention compared with the prior art are as follows: (1) The fish community structure stability index used in this invention can more effectively reflect the degree of ecosystem degradation than the population level index, and is therefore more suitable as the basis for selecting species for stock enhancement and release. The abundance-biomass comparison curve (ABC curve) method is based on the ecological r-selection and k-selection theories. It was initially used to monitor the impact of disturbance on benthic invertebrates. This method can determine the degree of community disturbance by the positional relationship between the biomass curve and the abundance curve and the W statistic value. Therefore, this invention is the first to apply the ABC curve method system to the screening of species for stock enhancement and release. With community structure stability as the core ecological element, it makes up for the shortcomings of existing selection criteria that focus on the suitability of the population itself. It can screen out species that play a key role in maintaining community structure stability, making the selection of species for stock enhancement and release more in line with the overall balance of the ecosystem and enriching the guidelines for responsible stock enhancement and release. (2) This invention conducts continuous spring and summer surveys for many years and combines W statistics to quantitatively analyze community stability, accurately screening out candidate species that play a key role in community stability. It avoids the blindness of traditional selection methods and improves the scientificity and accuracy of the selection of species for stock enhancement and release. (3) This invention comprehensively evaluates candidate species from multiple dimensions such as artificial seedling technology, nutrient relationship, energy flow contribution and recapture rate, taking into account ecological benefits and practical application feasibility, effectively improving the success rate of stock enhancement and release and avoiding the negative impact of blind release on the ecosystem. (4) The method of this invention has wide applicability. It can flexibly adjust the survey parameters and evaluation indicators according to the ecological characteristics and fishery resources of different target sea areas, providing a scientific basis for the formulation of guidelines for responsible stock enhancement and release in various places, and has important practical application value. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to specific embodiments.

[0015] This embodiment uses Laoshan Bay as the target sea area for verification. Based on the survey data from spring and summer of 2013-2015, the three-spined swimming crab (Portunus trituberculatus) was selected as the species for stock enhancement and release using the above-mentioned methods. This species is a benthic organism with mature artificial breeding technology. It mainly feeds on bivalves and crustaceans, and is also a food source for nearly 20 species of mid-to-upper-layer, near-benthic, and benthic organisms, exhibiting a complex nutritional relationship. Its bioturbation effect can promote energy flow, and it has a high historical recapture rate and population replenishment rate, which can effectively improve the stability of the swimming biological community structure in Laoshan Bay.

[0016] Step 1: Fishery Resource Survey of the Target Sea Area: The fishery resource survey of the target sea area includes statistical analysis of the biomass and abundance of various species in the target sea area. The survey area is Laoshan Bay, geographically located between 36° and 36.6° north latitude and 120.6° and 121° east longitude. This sea area is a natural cape bay connected to the Yellow Sea. In this embodiment, the survey stations are scientifically deployed in the Laoshan Bay area. The bay has a total area of ​​164.02 km², a coastline of 64.59 km, an average water depth of approximately 4 m, and a maximum water depth of 13 m. The station layout adhered to the core principles of full habitat coverage and gradient representativeness, combining water depth distribution and sediment type characteristics to fully cover the 0–5m shallow water area, the 5–10m transition zone, and the >10m deep water area. It accurately matched the zonal distribution of sediments such as sand, silty mud, and sandy sand from the bay crest to the bay mouth, covering major habitat types such as sandy, rocky reef, and silty mud, comprehensively reflecting the ecological characteristics of different habitats and providing reliable basic data support for the subsequent verification of screening methods. Fisheries trawling surveys were conducted in May (spring) and August (summer) from 2013 to 2015. The spring survey was conducted in May, during the breeding season of most marine organisms, and fishing activities had a certain impact on the swimming community structure. The summer survey was conducted in August, after the juveniles had matured and within the summer fishing moratorium, which could eliminate interference from fishing activities and the bias of small fish on the analysis results.

[0017] A 14.7kW single-boat trawler equipped with a bottom trawl (net width 3.75m, height 1.65m, mesh size 13mm) was used. Trawl was conducted for one hour at each survey station at a speed of 3.0 knots. Biological samples were collected and identified to the species level. Biomass and abundance of each species were calculated. A total of 86 species of swimming organisms were caught over three years, including 52 fish species, 28 benthic invertebrate species, and 6 mollusc species. Rare groups with a biomass percentage of less than 3% were excluded for further analysis.

[0018] Step 2, Community Structure Stability Analysis: The fishery resource quantity was estimated using the sea area survey method, and the structural stability of the swimming biological community and fish community was analyzed using the ABC curve method and W statistic. The formula for calculating the W statistic is W = ∑(B i -A i ) / s, Bi is the cumulative percentage of biomass, A i's' represents the cumulative percentage of abundance, and 's' represents the number of species captured. The x-axis of the ABC curve represents the number of species, and the y-axis represents the cumulative percentage of species biomass or abundance. When the biomass curve is above the abundance curve, the W statistic is positive, indicating a stable community structure with minimal disturbance. When the biomass curve intersects the abundance curve, it indicates a relatively stable community structure. When the biomass curve is below the abundance curve, the W statistic is negative, indicating a severely disturbed community structure. By comparing the ABC curve morphology and W statistic values ​​of swimming biological communities and fish communities, more stable community types can be screened.

[0019] The results showed that the W statistic of swimming communities was generally higher than that of fish communities in the spring and summer of 2013-2015. The biomass curve of fish was often below the abundance curve, while the biomass curve of swimming organisms was generally above or intersecting the abundance curve, indicating that the structure of swimming communities was more complex and stable than that of fish communities.

[0020] Step 3, Initial Screening of Candidate Species: Based on the community structure stability analysis results, the candidate species with the highest biomass proportion and significant contribution to community stability are selected as candidate species. Priority is given to benthic species. The biological disturbance activities of benthic organisms, such as feeding, crawling, predator avoidance, burrowing, and habitat construction, can promote the release of nitrogen and phosphorus from sediments, enhance microbial metabolic activity, transfer energy through the food chain, and maintain community structure stability.

[0021] In this embodiment, the main organisms in spring are *Dictyophora indica* and *Schizothorax spp.*, while those in summer are mainly *Schizothorax spp.*, *C. davidii*, and *Portunus trituberculatus*. Among these, *Portunus trituberculatus*, as a benthic organism, ranked among the top in biomass proportion in both spring 2015 and summer 2014-2015, playing a crucial role in maintaining the stability of the swimming organism community structure.

[0022] Step 4, Comprehensive Evaluation of Candidate Species: The comprehensive evaluation of candidate species is conducted based on the maturity of artificial breeding technology, the complexity of nutrient relationships, the contribution of energy flow, and the recapture rate. The candidate species are comprehensively evaluated from the following four dimensions: Maturity of artificial breeding technology: Species with mature artificial breeding technology and capable of large-scale cultivation are given priority to ensure the quantity and quality of released seedlings. In this embodiment, the artificial breeding technology of *Portunus trituberculatus* is very mature and can be cultivated on a large scale. The artificial breeding technology of *Mantis stolonifer* is not yet mature and it is difficult to meet the needs of large-scale release. The aquaculture technology of *Dictyophora indica* and *Russula davidii* is less widespread than that of *Portunus trituberculatus*.

[0023] Complexity of trophic relationships: The predatory species and the species preyed upon by candidate species are evaluated. Species with diverse predatory species and multiple food sources are given priority. Complex trophic relationships can enhance the stability of the ecosystem. In this embodiment, the swimming crab mainly feeds on bivalves, with crustaceans as a secondary food source, and small amounts of echinoderms and juvenile fish. At the same time, it is a food source for nearly 20 fish species, and its complex trophic relationships can enhance the stability of the ecosystem.

[0024] Energy flow contribution: The contribution of candidate species to the energy flow and cycle of the ecosystem is evaluated, including the impact on the release of nutrients from sediments and the efficiency of energy transfer in the food chain. Species that can accelerate the transfer of excess energy from specific trophic levels to energy-deficient trophic levels are given priority. In this embodiment, the bioturbation of the swimming crab (Portunus trituberculatus) can promote the release of nitrogen and phosphorus from sediments, providing energy to organisms at higher trophic levels through the upflow effect, while simultaneously transferring energy from the bottom water to the upper water through the downflow effect, thus maintaining the balance of the energy cycle.

[0025] Recapture rate: Based on historical fishery resource data, priority is given to species with high recapture rates and good population replenishment effects in the natural environment.

[0026] In this embodiment, the swimming crab (Portunus trituberculatus) is a long-term stock enhancement and release species in Laoshan Bay, with a high historical recapture rate and population replenishment rate. In 2021, it also became a joint stock enhancement and release species between China and South Korea in the Yellow Sea.

[0027] Step 5: Determine the species for stock enhancement and release: Based on the comprehensive evaluation results of candidate species, select candidate species with mature artificial seedling technology, complex trophic relationships, the ability to promote energy cycling, and high recapture rate as the final species for stock enhancement and release; if there are multiple species that meet the conditions, select a combination of multiple species for release based on the characteristics of the target marine ecosystem.

[0028] Based on the comprehensive evaluation results of this embodiment, the swimming crab (Portunus trituberculatus) was selected as the species for stock enhancement and release in Laoshan Bay. Stock enhancement and release of swimming crabs every spring can improve the stability of the swimming community structure in the subsequent summer through their trophic relationships and bio-disturbance effects. Li Zeng et al. (Li Zeng, Qiu Shengyao, Zhang Jinhao et al. Preliminary analysis of fishery biological community structure before and after release of *Portunus trituberculatus* in southern Shandong Peninsula [J]. Journal of Yantai University: Natural Science and Engineering Edition, 2014, 27(3): 184-190.) conducted a systematic analysis of the changes in fishery resource abundance biomass curves in six bays along the southern Shandong Peninsula in 2012. The results showed that after the release of *Portunus trituberculatus*, the fishery resource community structure in these six bays changed significantly. The degree of disturbance to the community structure decreased from severe to moderate, and the quality of the community structure was effectively improved. Among them, the biological evenness index of Laoshan Bay increased from the lowest value among the six bays before release to the highest value after release, and the biodiversity index also increased to a certain extent, confirming that *Portunus trituberculatus* has a clear stabilizing function in the fishery resource community structure of Laoshan Bay. The above research results are highly consistent with the analytical conclusions of the screening method in this application, fully confirming the accuracy and reliability of the screening method described in this application.

[0029] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for screening species for stock enhancement and release based on community structure stability, characterized in that, The process includes: a survey of fishery resources in the target sea area; analysis of community structure stability; preliminary screening of candidate species; comprehensive evaluation of candidate species; and determination of species for stock enhancement and release. The survey of fishery resources in the target sea area includes statistical analysis of the biomass and abundance of each species in the target sea area. The community structure stability analysis uses the sea area sweep method to estimate fishery resources and employs the ABC curve method and W statistic to analyze the structural stability of swimming and fish communities. The preliminary screening of candidate species, based on the results of the community structure stability analysis, selects species with high biomass proportions and significant contributions to community stability as candidate species. The comprehensive evaluation of candidate species assesses them based on the maturity of artificial breeding technology, complexity of trophic relationships, contribution to energy flow, and recapture rate. The determination of species for stock enhancement and release involves selecting candidate species with mature artificial breeding technology, complex trophic relationships, the ability to promote energy cycling, and a high recapture rate as the final species for stock enhancement and release, based on the comprehensive evaluation results. If multiple species meet the criteria, select a combination of species for release based on the characteristics of the target marine ecosystem.

2. The method for screening species for stock enhancement and release based on community structure stability according to claim 1, characterized in that, The survey sites should cover different water depths and habitat types; the survey should be conducted in the spring and summer seasons for at least 3 consecutive years.

3. The method for screening species for stock enhancement and release based on community structure stability according to claim 1, characterized in that, Furthermore, the formula for calculating the W statistic is W = ∑(B i -A i ) / s, Bi is the cumulative percentage of biomass, A i 's' represents the cumulative percentage of abundance, and 's' represents the number of species captured. The x-axis of the ABC curve represents the number of species, and the y-axis represents the cumulative percentage of species biomass or abundance. When the biomass curve is above the abundance curve, the W statistic is positive, indicating a stable community structure with minimal disturbance. When the biomass curve intersects the abundance curve, it indicates a relatively stable community structure. When the biomass curve is below the abundance curve, the W statistic is negative, indicating a severely disturbed community structure. By comparing the ABC curve morphology and W statistic values ​​of swimming biological communities and fish communities, more stable community types can be screened.

4. The method for screening species for stock enhancement and release based on community structure stability according to claim 1, characterized in that, In the initial screening of candidate species, priority is given to benthic species. The biological disturbance activities of benthic organisms, such as feeding, crawling, avoiding predators, burrowing, and habitat construction, can promote the release of nitrogen and phosphorus from sediments, enhance the metabolic activity of microorganisms, transfer energy through the food chain, and maintain the stability of community structure.

5. The method for screening species for stock enhancement and release based on community structure stability according to claim 1, characterized in that, In the comprehensive evaluation of the candidate species, priority is given to species with mature artificial seedling technology and large-scale cultivation; species with diverse predators and multiple food sources; species that can accelerate the transfer of excess energy from a specific trophic level to an energy-deficient trophic level; and species with high recapture rates and good population replenishment effects in the natural environment.

6. A system for screening species for stock enhancement and release based on community structure stability, characterized in that, The system includes a target sea area fishery resource survey module, a community structure stability analysis module, a candidate species initial screening module, a candidate species comprehensive evaluation module, and a module for determining the species to be released for stock enhancement. The target sea area fishery resource survey module inputs the survey results of the target sea area into this module, counts the biomass and abundance of each species in the target sea area, and inputs them into the community structure stability analysis module; the community structure stability analysis module uses the sea area sweeping method to estimate the amount of fishery resources, and uses the ABC curve method and W statistics to analyze the structural stability of swimming biological communities and fish communities. The results are then input into the candidate species screening module. The candidate species screening module selects species with high biomass proportions and significant contributions to community stability as candidate species based on the community structure stability analysis results. The results are then input into the candidate species comprehensive evaluation module. The candidate species comprehensive evaluation module comprehensively evaluates candidate species based on the input results, considering factors such as the maturity of artificial seedling cultivation technology, the complexity of nutrient relationships, the contribution of energy flow, and the recapture rate, and inputs the results into the module for determining the species to be released for propagation. The module for determining the species to be released for stock enhancement selects candidate species with mature artificial seedling technology, complex nutritional relationships, the ability to promote energy cycling, and a high recapture rate as the final species to be released for stock enhancement based on the comprehensive evaluation results of the candidate species. If multiple species meet the criteria, select a combination of species for release based on the characteristics of the target marine ecosystem, and output the final results.

7. A device for screening species for stock enhancement and release based on community structure stability, characterized in that, The device is equipped with the screening system described in claim 6.