A method for assessing the carbon footprint of abalone aquaculture systems throughout their life cycle

Abstract

The invention discloses a method for assessing the life cycle carbon footprint of an abalone breeding system, comprising the following steps: S1, determining a research purpose and a life cycle carbon footprint system boundary; S2, pre-processing field survey data, and constructing a social industrial process life cycle inventory; S3, collecting data on carbon released by calcification, organic carbon fixed by shells, and carbon buried by biological deposition in an abalone breeding process; S4, combining social industrial processes with natural processes, respectively calculating the carbon footprint of abalone breeding and the carbon balance of natural processes; S5, evaluating the impact of the calculation results and finding key carbon emission processes based on the contribution; the method can quantitatively assess the carbon footprint of a breeding process, identify key contribution links to carbon emission, and simultaneously consider the carbon balance of the natural process of abalone breeding, thereby improving the comprehensiveness of the carbon footprint assessment of abalone breeding and providing data support and scientific basis for realizing the green and low-carbon development of the abalone industry.

Description

Technical Field

[0001] The invention relates to the technical field of carbon footprint, and in particular to a method for assessing the life cycle carbon footprint of an abalone breeding system. Background Art

[0002] Climate change is one of the main issues facing the food system. Blue Foods can provide high-quality protein for the human body and have great potential to ensure food security. Due to the reduction of natural fishery resources and the growing demand for aquatic products, marine aquaculture has gradually played a key role in the production of blue carbon foods. Carbon footprint assessment and carbon emission reduction in the marine aquaculture industry have become a hot topic in environmental management in recent years. Currently, a number of life cycle carbon footprint assessment studies have been conducted on some marine aquaculture products.

[0003] Abalone is one of the most important shellfish in the world in fisheries and aquaculture. There are three main abalone farming models in my country, namely the sea area raft-local farming model, the sea area raft-Southern abalone and northern farming model, and the land-based factory farming model. The sea area raft-local farming model refers to a farming method in which floats and ropes are used to form a floating raft on the shallow sea surface, and the rafts are fixed to the seabed with cables, so that the seedlings of seaweed (such as kelp and laver) and sessile animals (such as mussels) are fixed on the hanging ropes and suspended on the floating raft. The purpose of the sea area raft-Southern abalone and northern farming model is to improve the survival rate of abalone farming and produce larger abalone, that is, abalone is mainly farmed in Fujian in southern China in winter, and abalone is mainly transported to Shandong and Liaoning in northern China for farming in summer. This farming model allows abalone to grow at a suitable temperature all year round, shortening the growth time and improving the survival rate of abalone farming. The land-based factory farming model builds breeding ponds indoors (in workshops), uses automated equipment and technology to treat and recycle aquaculture water, automatically monitors and controls water temperature, water quality, dissolved oxygen, and light, and adopts high-density stocking and intensive feeding methods for production. It is a highly intensive farming method that can avoid typhoons, high temperatures, and other natural disasters.

[0004] Current research on the carbon footprint of abalone farming has problems such as unclear system boundaries and missing life cycle inventory data (such as insufficient calculation of infrastructure and equipment, and carbon balance of natural systems), making it impossible to scientifically conduct carbon footprint assessments of abalone farming systems. Summary of the invention

[0005] To solve the above problems, the present invention proposes a carbon footprint assessment method for analyzing abalone farming systems, taking into account three abalone farming modes: "land-based factory farming", "sea raft-local farming" and "sea raft-north-south farming", and comprehensively assessing the impact of factors such as material input in the farming system on the carbon footprint generated.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for assessing the carbon footprint of an abalone aquaculture system during its life cycle comprises the following steps:

[0008] S1. Determine the research purpose and the boundaries of the life cycle carbon footprint system;

[0009] S2, pre-process the field survey data and construct a life cycle inventory of social industrial processes;

[0010] S3. Collect data on carbon released by calcification, organic carbon fixed in shells, and carbon buried in biological deposition during abalone farming. The specific calculation formula is: ; ; Among them, C cal represents carbon released by calcification; DSW represents shell dry weight; IC shell represents the inorganic carbon content of the shell; Φ represents CO 2 Release coefficient; C shell represents shell-fixed organic carbon; OC shell Indicates the organic carbon content of the shell; C sed represents the carbon buried in biological deposition; F represents the carbon contained in feces; r represents the remineralization coefficient of feces;

[0011] Φ is calculated using the psi function in the seacarb package in R, with BFlag = 21, and the pCO of the aquaculture water is entered. 2 , pH, temperature and salinity;

[0012] F is calculated based on the carbon balance equation of abalone. Abalone has a carbon balance relationship in the natural process, and the carbon balance relationship is expressed as 2.09C=0.23G+1.15R+0.71F; among them, C is the ingested carbon; F is the carbon contained in the feces; R is the respiratory carbon; G is the growth carbon, that is, the total carbon content in the soft tissue of abalone; among them, C, G and R are all known quantities, and F is calculated based on the carbon balance relationship;

[0013] S4. Combine social industrial processes with natural processes to calculate the carbon footprint of abalone farming and the carbon budget of natural processes;

[0014] The specific process of step S4 is as follows: The social industrial process carbon footprint assessment first analyzes the inventory data, collects the resource and energy consumption of the abalone farming system, and then determines its emission factor. The carbon footprint calculation formula for abalone farming is: Among them, C s Represents the total carbon emissions of social industrial processes; V i represents the consumption of the i-th resource or energy; F irepresents the emission factor of the i-th resource or energy; i represents the various resources and energy input into the social industrial process; n represents the total number of input resource and energy types;

[0015] Based on the inventory data, the abalone farming system was modeled using openLCA software and ecoinvent database, and a life cycle assessment was conducted using the ReCipe 2016v1.1 Midpoint indicator;

[0016] The calculation formula of abalone natural process carbon budget is: Among them, C n represents the carbon budget of natural processes, C n When the calculated result is positive, it means that the abalone is a carbon source through natural process, C n When the result is negative, it means that the abalone natural process is a carbon sink;

[0017] S5. Evaluate the impact of the calculation results and find the key carbon emission processes based on their contribution.

[0018] Preferably, the research purpose described in step S1 is to analyze the carbon emissions caused by energy and resource inputs in each process of abalone farming through a life cycle model; the functional unit is defined as the output of 1 t of fresh weight abalone in shell; the life cycle carbon footprint system boundary includes all life cycle stages of abalone from seedlings to adult abalone; the abalone seedling stage includes four processes of parent abalone cultivation, seedling cultivation, seedling cultivation and seedling separation; the abalone farming stage includes management during the farming period.

[0019] Preferably, the specific process of step S2 is: collecting material input data in the breeding system for constructing a social industrial process life cycle inventory; the material input data includes energy data, infrastructure input data, breeding equipment input data, feed production data and transportation data; wherein the transportation data includes feed transportation data, seedling transportation data and transportation data for north-south breeding; collecting natural process data of abalone for natural process carbon budget calculation in steps S3 and S4.

[0020] Preferably, the specific process of step S5 is: analyzing the results of the social industrial process carbon footprint life cycle assessment and the carbon balance results of the natural process, evaluating the carbon footprint of abalone farming, identifying the key influencing factors of the carbon footprint, and proposing low-carbon farming improvement suggestions based on actual production conditions to reduce the carbon footprint of the abalone farming system.

[0021] After adopting the above technical scheme, the present invention has the following beneficial effects: the present invention comprehensively analyzes the carbon footprint of the social industrial process and the carbon balance of the natural process from abalone seedling cultivation to adult breeding, can quantitatively evaluate the carbon footprint of the breeding process, identify the key contribution links of carbon emissions, and at the same time consider the carbon balance of the natural process of abalone breeding, thereby improving the comprehensiveness of the carbon footprint assessment of abalone breeding and providing data support and scientific basis for realizing the green and low-carbon development of the abalone industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the process of the present invention;

[0023] Figure 2 A schematic diagram of the boundary of the abalone farming life cycle carbon footprint assessment system of the present invention;

[0024] Figure 3 Schematic diagram of carbon footprint analysis of three typical abalone farming models in the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0026] like Figures 1 to 3 As shown, a method for assessing the carbon footprint of an abalone farming system life cycle comprises the following steps:

[0027] S1. Determine the research purpose and the boundaries of the life cycle carbon footprint system;

[0028] The research purpose described in step S1 is to analyze the carbon emissions caused by energy and resource inputs in each process of abalone farming through a life cycle model; the functional unit is defined as the output of 1 t of fresh weight abalone in shell; the life cycle carbon footprint system boundary includes all life cycle stages of abalone from seedlings to adult abalone; the abalone seedling stage includes four processes of parent abalone cultivation, seedling cultivation, seedling cultivation and seedling separation; the abalone farming stage includes management during the farming period;

[0029] This example takes abalone farming as an example. The life cycle carbon footprint system boundary includes abalone parent cultivation, seedling raising, seedling division, land-based farming or sea raft farming, and does not consider infrastructure and equipment maintenance. Figure 2 shown.

[0030] S2, pre-process the field survey data and construct a life cycle inventory of social industrial processes;

[0031] The specific process of step S2 is: collecting material input data in the aquaculture system for constructing a social industrial process life cycle inventory; the material input data includes energy data, infrastructure input data, aquaculture equipment input data, feed production data and transportation data; wherein the transportation data includes feed transportation data, seedling transportation data and transportation data of north-south aquaculture; collecting abalone natural process data for natural process carbon budget calculation in steps S3 and S4;

[0032] This example takes an abalone farm in Fujian Province as the research object, and records in detail all aspects from feed production to aquaculture management. Through the application of openLCA software, the output of 1t fresh weight abalone in shell is used as the research object, and the carbon footprint under different aquaculture modes is deeply analyzed. The results show that the carbon footprint of the land-based factory farming model is significantly higher than that of the sea area raft farming model, among which electricity consumption is the main source of carbon emissions. The list includes front-end (such as feed production, feed and seedling transportation, water supply and infrastructure construction) and back-end (such as energy production, aquaculture equipment manufacturing) data. Among them, the system inputs in the seedling stage include abalone compound feed (fish meal, soybean), infrastructure (concrete, polyethylene), water, electricity, and fuel (diesel); the system inputs of land-based factory farming in the aquaculture stage are feed (grassroots), infrastructure (concrete, polyethylene), water, electricity, and transportation. The input lists of the sea area raft-local aquaculture model and the sea area raft-north-south aquaculture model include feed (grassroots), infrastructure (nylon, polyethylene, wood), fuel (diesel), and transportation. The front-end data comes from the field survey of the breeding enterprises, and the back-end data such as electricity, diesel and polyethylene come from the ecoinvent v3.8 database;

[0033] S3. Collect data on carbon released by calcification, organic carbon fixed in shells, and carbon buried in biological deposition during abalone farming. The specific calculation formula is: ; ; Among them, C cal represents carbon released by calcification; DSW represents shell dry weight; IC shell represents the inorganic carbon content of the shell; Φ represents CO 2 Release coefficient; C shell represents shell-fixed organic carbon; OC shell Indicates the organic carbon content of the shell; C sed represents the carbon buried in biological deposition; F represents the carbon contained in feces; r represents the remineralization coefficient of feces;

[0034] Φ is calculated using the psi function in the seacarb package in R, setting BFlag = 21 and inputting the pCO of the aquaculture water. 2 , pH, temperature and salinity;

[0035] F is calculated based on the carbon balance equation of abalone. Abalone has a carbon balance relationship in the natural process, and the carbon balance relationship is expressed as 2.09C=0.23G+1.15R+0.71F; among them, C is the ingested carbon; F is the carbon contained in the feces; R is the respiratory carbon; G is the growth carbon, that is, the total carbon content in the soft tissue of abalone; among them, C, G and R are all known quantities, and F is calculated based on the carbon balance relationship;

[0036] S4. Combine social industrial processes with natural processes to calculate the carbon footprint of abalone farming and the carbon budget of natural processes;

[0037] The specific process of step S4 is as follows: The social industrial process carbon footprint assessment first analyzes the inventory data, collects the resource and energy consumption of the abalone farming system, and then determines its emission factor. The carbon footprint calculation formula for abalone farming is: Among them, C s Represents the total carbon emissions of social industrial processes; V i represents the consumption of the i-th resource or energy; F i represents the emission factor of the i-th resource or energy; i represents the various resources and energy input into the social industrial process; n represents the total number of input resource and energy types;

[0038] Based on the inventory data, the abalone farming system was modeled using openLCA software and ecoinvent database, and a life cycle assessment was conducted using the ReCipe 2016v1.1 Midpoint indicator;

[0039] The calculation formula of abalone natural process carbon budget is: Among them, C n represents the carbon budget of natural processes, C n When the calculated result is positive, it means that the abalone is a carbon source through natural process, C n When the result is negative, it means that the abalone natural process is a carbon sink;

[0040] S5. Evaluate the impact of the calculation results and find the key carbon emission processes based on their contribution;

[0041] The specific process of step S5 is: analyzing the carbon footprint life cycle assessment results of the social industrial process and the carbon budget results of the natural process, evaluating the carbon footprint of abalone farming, identifying the key influencing factors of the carbon footprint, and proposing low-carbon farming improvement suggestions based on actual production conditions to reduce the carbon footprint of the abalone farming system;

[0042] The carbon footprint assessment results of abalone farming system are as follows: Figure 3 The results show that the carbon footprint of each ton of abalone produced is affected by different farming modes. Land-based factory farming (5682kgCO 2eq) is higher than the sea area raft-local mode (1915kgCO 2 eq) and sea raft culture-north-south culture model (1473 kgCO 2 eq). The main carbon footprint contributor of the land-based factory farming model is electricity input (72%). The farming models of the raft farming systems in the two sea areas are similar. The main carbon footprint contributor of local farming is seedling cultivation (63%); the main carbon footprint contributor of the north-south farming model is seedling cultivation (51%), but it requires more infrastructure investment (41%) than local farming. In addition, this case calculated the natural carbon budget of 1 ton of fresh abalone in shell. The results showed that the natural abalone farming process is a carbon source (emissions are 24.65 kgCO 2 eq).

[0043] This example quantifies the carbon footprint of the three abalone farming models during their life cycle, identifies the key contributing processes that affect the carbon footprint, and proposes suggestions for improving low-carbon farming. This provides a more systematic and comprehensive understanding of the abalone farming system and provides a reference for improving the sustainability of the farming industry system.

[0044] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for assessing the carbon footprint of an abalone aquaculture system during its life cycle, characterized in that: The following steps are involved: S1. Determine the research purpose and the boundaries of the life cycle carbon footprint system; S2, pre-process the field survey data and construct a life cycle inventory of social industrial processes; S3. Collect data on carbon released by calcification, organic carbon fixed in shells, and carbon buried in biological deposition during abalone farming. The specific calculation formula is: ; ; Among them, C cal represents carbon released by calcification; DSW represents shell dry weight; IC shell represents the inorganic carbon content of the shell; Φ represents the CO2 release coefficient; C shell represents shell-fixed organic carbon; OC shell Indicates the organic carbon content of the shell; C sed represents the carbon buried in biological deposition; F represents the carbon contained in feces; r represents the remineralization coefficient of feces; Φ is calculated using the psi function in the seacarb package of the R language, with BFlag = 21 set, and the four parameters of the aquaculture water body, pCO2, pH, temperature, and salinity, are input; F is calculated based on the carbon balance equation of abalone. Abalone has a carbon balance relationship in the natural process, and the carbon balance relationship is expressed as 2.09C=0.23G+1.15R+0.71F; among them, C is the ingested carbon; F is the carbon contained in the feces; R is the respiratory carbon; G is the growth carbon, that is, the total carbon content in the soft tissue of abalone; among them, C, G and R are all known quantities, and F is calculated based on the carbon balance relationship; S4. Combine social industrial processes with natural processes to calculate the carbon footprint of abalone farming and the carbon budget of natural processes; The specific process of step S4 is as follows: The social industrial process carbon footprint assessment first analyzes the inventory data, collects the resource and energy consumption of the abalone farming system, and then determines its emission factor. The carbon footprint calculation formula for abalone farming is: Among them, C s Represents the total carbon emissions of social industrial processes; V i represents the consumption of the i-th resource or energy; F i represents the emission factor of the i-th resource or energy; i represents the various resources and energy input into the social industrial process; n represents the total number of input resource and energy types; Based on the inventory data, the abalone farming system was modeled using openLCA software and ecoinvent database, and a life cycle assessment was conducted using the ReCipe 2016v1.1 Midpoint indicator; The calculation formula of abalone natural process carbon budget is: Among them, C n represents the carbon budget of natural processes, C n When the calculated result is positive, it means that the abalone is a carbon source through natural process, C n When the result is negative, it means that the abalone natural process is a carbon sink; S5. Evaluate the impact of the calculation results and find the key carbon emission processes based on their contribution.

2. A method for assessing the life cycle carbon footprint of an abalone aquaculture system as claimed in claim 1, characterized in that: The research purpose described in step S1 is to analyze the carbon emissions caused by energy and resource inputs in each process of abalone farming through a life cycle model; the functional unit is defined as the output of 1 t of fresh weight abalone in shell; the life cycle carbon footprint system boundary includes all life cycle stages of abalone from seedlings to adult abalone; the abalone seedling stage includes four processes: parent abalone cultivation, seedling cultivation, seedling cultivation and seedling separation; the abalone farming stage includes management during the farming period.

3. A method for assessing the life cycle carbon footprint of an abalone aquaculture system as claimed in claim 1, characterized in that: The specific process of step S2 is: collecting material input data in the breeding system for constructing a social industrial process life cycle inventory; the material input data includes energy data, infrastructure input data, breeding equipment input data, feed production data and transportation data; among them, the transportation data includes feed transportation data, seedling transportation data and transportation data for north-south breeding; collecting abalone natural process data for natural process carbon balance calculation in steps S3 and S4.

4. A method for assessing the life cycle carbon footprint of an abalone aquaculture system as claimed in claim 1, characterized in that: The specific process of step S5 is: analyzing the results of the social industrial process carbon footprint life cycle assessment and the carbon budget results of the natural process, evaluating the carbon footprint of abalone farming, identifying the key influencing factors of the carbon footprint, and proposing low-carbon farming improvement suggestions based on actual production conditions to reduce the carbon footprint of the abalone farming system.

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