**6. Safety measures**

**5. Valorisation of milk from goats in Lebanon**

**Figure 7.** Flow diagram of production of *Kish* (adopted from Tamime and Robinson [2]).

Artisanal cheeses refer to cheeses prepared by hand using the unique craftsmanship of the cheese maker. They are usually prepared within family of traditional goat farming in Lebanon, which is an ancestral heritage that could disappear by the overflowing of new technologies, and its protection is necessary for the preservation of patrimonial traditions that support Lebanese regions. These products with all particular practices and customs of production appear as a property bequeathed to the Lebanese community, a legacy. Therefore, it is necessary to improve the craft products, built on their cultural property and to give them a

The technology and composition of most goat cheeses, especially the traditional ones, are not well-documented [29]. The production of traditional goat cheeses is usually carried out on individual farms by shepherds themselves and their families. Most of these cheeses are produced traditionally and manufacturing methods are passed from generation to generation without a technology and regulations standards or pasteurization [30]. Cheeses made under these conditions do not have the minimum hygiene and sanitary guarantees necessary to

The real value of goat cheese is through industrialization under technical and scientific conditions capable of providing products with the indispensable guarantees of quality and constancy [29]. According to the René Moawad Foundation (RMF), Darfiyeh cheese became the first Lebanese artisan produce in the Middle East to receive the 'Presidium' quality level attributed by the

**5.1. Prospects for protection of dairy products**

390 Goat Science

symbolic dimension and a specific attention.

obtain constant product quality.

**5.2. Attempts of safeguarding artisanal products**

While it is obvious that the consumer expects the guarantee of high quality, consistent taste, function and the benefits of food safety of cheese, the cheese makers on the other hand want the old style feel to their cheese: all natural, full flavour, and simple packaging. This has been a major issue in the sales decline of artisanal cheeses. New educated generations are opting for store-bought cheese produced by international manufacturers guarantying safety. However, in the case of artisanal goat cheeses, the desires of both the producer and the consumer can be satisfied if done properly. The key to customer satisfaction depends on focusing on food safety at every step of the cheese manufacturing process without changing the integrity of artisanal cheese-making.

Moreover, GMP is essential for the implementation of management systems and is the starting point to any food safety system whether Hazard Analysis and Critical Control Point (HACCP), ISO 22000 International Standards Organization, or British Retail Consortium

The Goat Dairy Sector in Lebanon

393

http://dx.doi.org/10.5772/intechopen.70077

General measures to be implemented by food industries to accomplish with GMP as described

Although *the Codex Alimentarius* [32, 33] and the Lebanese government may establish general and national guidelines for hygienic practices, the practical implementation to address regulatory requirements procedures adopted consistently by each industry or farm might vary among them. Thus, there is a need to document the practices of each factory in GMP manuals

The implementation of GMPs is a continuous practice based on the management concepts of

Considering the PDCA cycle, the implementation of GMPs can be divided in four steps: initial diagnosis that includes identifying and addressing safety risks and opportunities, elaboration of road map, addressing of non-conformities and re-evaluation of corrective measures implemented. Initial diagnosis and re-evaluation of corrective measures implemented are usually done by a premises audit visit using a checklist based on the legislation regulating the GMPs in the country. Finally, road maps are generated, based on the previous audit, and corrective

Regarding the artisanal cheese-making, implementing the GMPs must be cost effective because of the size of the business is usually of small scale, so several indicators can be used to evaluate the benefits of the implementation of GMPs such as microbiological indicators and

Typical conditions regarding lack of compliance with GMP in artisanal cheese-making usu-

Presence of insects and domestic animals as well as unused equipment in the external area, absence of recording thermometers, cracked floor and stone walls, absence of personnel hygiene, food additives in unlabelled containers, use of wooden materials entering into contact with the food, lamps with no protective covers, hoses lying on the floor, personnel not wearing appropriate garments and footwear for working in a food processing plant, and not

measures based on resource priorities and efforts are implemented [34].

perhaps increased appeal to consumers that leads to increased sales.

trained in GMP, and no enforcement of hygienic practices [34].

(BRC).

ally include:

by *Codex Alimentarius* include [33]:

• processes necessary for primary production

• training, documentation and consumer awareness

• design of the premises and equipment

• hygiene of the handling personnel

• sanitation and maintenance practices

to obtain high quality and safe foods [34].

the plan, do, check and action (PDCA) cycle.

#### **6.1. Poor handling procedures**

Most of these cheeses are produced traditionally which means manufacturing methods are passed from generation to generation without a standard technology, standard regulations or pasteurization [30]. Cheeses made under these conditions do not have the minimum hygiene and sanitary guarantees necessary to obtain constant product quality.

Raw goat milk does not undergo any pathogen elimination or reduction step, therefore its safety is mainly dependent on the control of the risk factors that may induce contamination during the cheese-making. Minimizing microbiological hazards that may allow the growth of pathogens by maintaining a hygienic handling and controlling appropriate temperature control during storage and distribution.

Only very few farmers have the innovation capacity to follow the correct milking and handling procedures. Goat milk handling is very primitive with almost no cooling devices for the collected milk, and very poor hygienic conditions linked to the cleaning and disinfection of the utensils, which means poor control over zoonotic diseases. This situation is only true with small holders and poor farmers [8]. The few large holdings with large investment and very modern facilities that exist in Lebanon follow the international norms and standards of milking, handling, hygiene and control of quality.

*Brucellosis* is quite frequent with some 13% of the livestock affected in 2002, and a high level of infection of humans. Other sanitary problems are also present and have a serious impact on the livestock population. For example, organisms frequently associated with human illness linked to consumption of dairy products are *Campylobacter* spp., pathogenic *Escherichia coli*, *Listeria monocytogenes, Salmonella* spp. and *Staphylococcus aureus*.

In the case of a disease-free goat, the routes in which the disease-causing pathogens enter milk are usually through lack of temperature control, or poor farm and personnel sanitation. A correctly run farm therefore, will have milk that is safe to drink right out of the goat [31].

#### **6.2. Good manufacturing practices**

The implementation of good manufacturing practices (GMP) during milking and dairy processing in small farms might help them reduce the contamination of dairy products by biological, chemical and physical hazards [32]. GMP defines the series of general measures to be implemented by the food industries to ensure the safety of the process and conformity of food products to precise guidelines.

Moreover, GMP is essential for the implementation of management systems and is the starting point to any food safety system whether Hazard Analysis and Critical Control Point (HACCP), ISO 22000 International Standards Organization, or British Retail Consortium (BRC).

General measures to be implemented by food industries to accomplish with GMP as described by *Codex Alimentarius* include [33]:

been a major issue in the sales decline of artisanal cheeses. New educated generations are opting for store-bought cheese produced by international manufacturers guarantying safety. However, in the case of artisanal goat cheeses, the desires of both the producer and the consumer can be satisfied if done properly. The key to customer satisfaction depends on focusing on food safety at every step of the cheese manufacturing process without changing the integ-

Most of these cheeses are produced traditionally which means manufacturing methods are passed from generation to generation without a standard technology, standard regulations or pasteurization [30]. Cheeses made under these conditions do not have the minimum hygiene

Raw goat milk does not undergo any pathogen elimination or reduction step, therefore its safety is mainly dependent on the control of the risk factors that may induce contamination during the cheese-making. Minimizing microbiological hazards that may allow the growth of pathogens by maintaining a hygienic handling and controlling appropriate temperature

Only very few farmers have the innovation capacity to follow the correct milking and handling procedures. Goat milk handling is very primitive with almost no cooling devices for the collected milk, and very poor hygienic conditions linked to the cleaning and disinfection of the utensils, which means poor control over zoonotic diseases. This situation is only true with small holders and poor farmers [8]. The few large holdings with large investment and very modern facilities that exist in Lebanon follow the international norms and standards of

*Brucellosis* is quite frequent with some 13% of the livestock affected in 2002, and a high level of infection of humans. Other sanitary problems are also present and have a serious impact on the livestock population. For example, organisms frequently associated with human illness linked to consumption of dairy products are *Campylobacter* spp., pathogenic *Escherichia coli*,

In the case of a disease-free goat, the routes in which the disease-causing pathogens enter milk are usually through lack of temperature control, or poor farm and personnel sanitation. A correctly run farm therefore, will have milk that is safe to drink right out of the goat [31].

The implementation of good manufacturing practices (GMP) during milking and dairy processing in small farms might help them reduce the contamination of dairy products by biological, chemical and physical hazards [32]. GMP defines the series of general measures to be implemented by the food industries to ensure the safety of the process and conformity of food

and sanitary guarantees necessary to obtain constant product quality.

rity of artisanal cheese-making.

392 Goat Science

**6.1. Poor handling procedures**

control during storage and distribution.

**6.2. Good manufacturing practices**

products to precise guidelines.

milking, handling, hygiene and control of quality.

*Listeria monocytogenes, Salmonella* spp. and *Staphylococcus aureus*.

• sanitation and maintenance practices

Although *the Codex Alimentarius* [32, 33] and the Lebanese government may establish general and national guidelines for hygienic practices, the practical implementation to address regulatory requirements procedures adopted consistently by each industry or farm might vary among them. Thus, there is a need to document the practices of each factory in GMP manuals to obtain high quality and safe foods [34].

The implementation of GMPs is a continuous practice based on the management concepts of the plan, do, check and action (PDCA) cycle.

Considering the PDCA cycle, the implementation of GMPs can be divided in four steps: initial diagnosis that includes identifying and addressing safety risks and opportunities, elaboration of road map, addressing of non-conformities and re-evaluation of corrective measures implemented. Initial diagnosis and re-evaluation of corrective measures implemented are usually done by a premises audit visit using a checklist based on the legislation regulating the GMPs in the country. Finally, road maps are generated, based on the previous audit, and corrective measures based on resource priorities and efforts are implemented [34].

Regarding the artisanal cheese-making, implementing the GMPs must be cost effective because of the size of the business is usually of small scale, so several indicators can be used to evaluate the benefits of the implementation of GMPs such as microbiological indicators and perhaps increased appeal to consumers that leads to increased sales.

Typical conditions regarding lack of compliance with GMP in artisanal cheese-making usually include:

Presence of insects and domestic animals as well as unused equipment in the external area, absence of recording thermometers, cracked floor and stone walls, absence of personnel hygiene, food additives in unlabelled containers, use of wooden materials entering into contact with the food, lamps with no protective covers, hoses lying on the floor, personnel not wearing appropriate garments and footwear for working in a food processing plant, and not trained in GMP, and no enforcement of hygienic practices [34].

In addition, production personnel in Lebanon usually gain from past generations of cheese makers, but lack scientific and technological training to realize the consequences of their cheese handling.

[4] Toufeili I, Shadarevian S, Artinian T, Tannous R. Ripening changes and sensory properties of bovine, carpine, and ovine Shankleesh. International Dairy Journal. 1995;**5**:179-189

The Goat Dairy Sector in Lebanon

395

http://dx.doi.org/10.5772/intechopen.70077

[5] Serhan M, Mattar J, Debs L. Concentrated yogurt (Labneh) made of a mixture of goats' and cows' milk: Physicochemical, microbiological and sensory analysis. Small Ruminant

[6] Salameh C, Banon S, Hosri CH, Scher J. An overview of recent studies on the main traditional fermented milks and white cheeses in the Mediterranean region. Food Reviews

[7] FAO. Lebanese Observatory for Agricultural Development Project. Agricultural Census.

[9] Khalifat G. Fiche de synthèse: la grande distribution au Liban. DREE-Mission économique de Beyrouth. Lebanon: Ministry of Agriculture; 2003. Available from: ifsa.boku.ac.at/

[10] Mercy Corps. Protect and Provide Livelihoods in Lebanon: Small Ruminant Dairy Chain

[11] Institut de l'élevage Les filières lait et viande de ruminants au Liban. Compte rendu

[12] El Balaa R, Marie M, Abi Saab S. Consumer's choice of small ruminants products in relation to sustainability in Lebanon in Animal products from the Mediterranean area,

[13] Ministry of Agriculture. Republic of Lebanon Directorate of Studies & Coordination.

[14] Devendra C. Comparative aspects of digestive physiology and nutrition in goats and sheep. In: Devendra C, Imaizumi E, editors. Proceedings VIIth International. Ruminant

[15] Haenlein GFW. Advances in the nutrition of macro- and micro-elements in goats. Proceedings Vth International Conference on Goats; New Delhi, India. III, 1992:933-950

[16] Serhan M, Linder M, Hosri C, Fanni J. Changes in proteolysis and volatile fraction during ripening of Darfiyeh, a Lebanese artisanal raw goat's milk cheese. Small Ruminant

[17] Hosri CH, El Khoury N. Valoriser le fromage de chèvre traditionnel « Darfiyeh » pour aider au développement de la région montagnarde nord libanaise. Options méditer-

[18] Serhan M, Hosri C, Cailliez-Grimal C, Fanni J. Characteristics of Lebanese Darfiyeh cheese made from raw goat milk. In: Proceedings of the CRA/IGA, International the Quality of Goat Products: Models and Tools for Evaluation and Promotion. Symposium

conducted at the International Goat Association, Bella (PZ), Italy. 2007. pp. 66-69

Physiology. Sendai, Japan: Japan Zootechnology Science; 1989. pp. 45-60

[8] FAO. Country Pasture/Forage Resource Profiles LEBANON – Fady Asmar. 2011

cms/fileadmin/Proceeding2008/2008\_WS2\_06\_Balaa.pdf

Symposium conducted at the Santarém, Portugal. 2005

Lebanon: Agricultural Statistical Analysis. 2005

d'étude [Unpublished Master's thesis]. Beirut, Lebanon: 2003. 98

Research. 2016;**138**:46-52

2010

Assessment. 2014

Research. 2010;**90**:75-82

ranéennes, Série A. 2004;**61**:201-206

International. 2016;**32**(3):256-279

Some vital recommendations for the dairy processing industry include [34]:

It is also recommended that the dairy processing industry receives training in novel cheesemaking technologies.

The existence of a manual describing how GMPs are accomplished by each processing plant is of foremost importance to ensure their continuous evaluation and improvement by processing plants, governments and partners [31].

Therefore, distributing manuals to all artisanal cheese makers seems a fundamental step in educating them about the minimal procedures to follow to guarantee safe cheese. Arabic printed, and loaded with picture should be the adopted format that enables everyone to understand required guidelines.

#### **Author details**

Mireille Serhan1 \* and Jessy Mattar2

\*Address all correspondence to<EMAIL_ADDRESS>
1 University of Balamand, Faculty of Health Sciences, Tripoli, Lebanon

2 Farrelly & Mitchell Business Consultants Ltd, Beirut, Lebanon

#### **References**

[4] Toufeili I, Shadarevian S, Artinian T, Tannous R. Ripening changes and sensory properties of bovine, carpine, and ovine Shankleesh. International Dairy Journal. 1995;**5**:179-189

In addition, production personnel in Lebanon usually gain from past generations of cheese makers, but lack scientific and technological training to realize the consequences of their

**a.** Build strong relationship with milk producers, in case other than themselves, to improve

It is also recommended that the dairy processing industry receives training in novel cheese-

The existence of a manual describing how GMPs are accomplished by each processing plant is of foremost importance to ensure their continuous evaluation and improvement by process-

Therefore, distributing manuals to all artisanal cheese makers seems a fundamental step in educating them about the minimal procedures to follow to guarantee safe cheese. Arabic printed, and loaded with picture should be the adopted format that enables everyone to

[1] Lebanese Ministry of Agriculture. Lebanon: Agricultural Statistical Analysis. Available

[2] Tamime AY, Robinson RK, editors. Yogurt Science and Technology. 3rd ed. Cambridge,

[3] Serhan M, Mattar J. Characterization of four Lebanese artisanal goat milk cheeses: Darfiyeh, Aricheh, Shankleesh and Serdale by physico-chemical, microbiological and

sensory analyses. Journal of Food Agriculture and Environment. 2013;**11**:97-101

Some vital recommendations for the dairy processing industry include [34]:

milk quality and quantity, together, in win-win relationships,

**d.** when the proper time arrives, adopt HACCP and ISO.

ing plants, governments and partners [31].

\* and Jessy Mattar2

UK: Woodhead Publishing; 2007

\*Address all correspondence to<EMAIL_ADDRESS>
2 Farrelly & Mitchell Business Consultants Ltd, Beirut, Lebanon

from: www.agriculture.gov.lb [Accessed: March 2010]

1 University of Balamand, Faculty of Health Sciences, Tripoli, Lebanon

understand required guidelines.

**b.** improve compliance with GMPs after being trained of its principles,

**c.** train everyone in fundamentals of dairy processing science and technology and

cheese handling.

394 Goat Science

making technologies.

**Author details**

Mireille Serhan1

**References**

[19] Serhan M, Cailliez-Grimal C, Borges F, Revol-Junelles A, Hosri C, Fanni J. Bacterial diversity of Darfiyeh, a Lebanese artisanal raw goat's milk cheese. Food Microbiology.

[20] Dagher S. Traditional foods in the near East. FAO Food and Nutrition Paper. 1991;**50**:71-72 [21] Guizani N, Al-Attabi Z. Ripening profile of semi-hard standard. Goat cheese made from

[22] Haenlein GFW. Goat milk in human nutrition. Small Ruminant Research. 2004;**51**:155-163 [23] Zouhairi O, Saleh I, Alwan N, Toufeili I, Barbour E, Harakeh S. Antimicrobial resistance of *Staphylococcus* species isolated from Lebanese dairy-based products. Eastern

[24] Ozer BH, Stenning RA, Grandison AS, Robinson RK. Rheology and microstructure of

[25] Al-Kadamany E, Toufeili I, Khattar M, Abou-Jawdeh Y, Harakeh S, Haddad T. Determination of shelf life of concentrated yogurt (Labneh): Produced by In-Bag straining of set yogurt using hazard analysis. Journal of Dairy Science. 2002;**85**:1023-1030 [26] Al-Kadamany E, Khattar M, Haddad T, Toufeili I. Estimation of shelf-life of concentrated yogurt by monitoring selected microbiological and physicochemical changes dur-

[27] Kaaki D, Kebbe Baghdadi O, Najm NE, Olabi A. Preference mapping of commercial Labneh (strained yogurt) products in the Lebanese market. Journal of Dairy Science.

[28] Haddad Y, Haddad J, Olabi A, Shuayto N, Haddad T, Toufeili I. Mapping determinants of purchase intent of concentrated yogurt (Labneh) by conjoint analysis. Food Quality

[29] Godina AL. Hard and semi-hard cheese from sheep and goats'milk. (Report No. 202).

[30] Klinger I, Rosenthal I. Public health and the safety of milk and milk products from sheep

[31] Irish DA. Items to be Included in a Handbook of Food Safety for Artisan Cheese Makers

[32] Codex Alimentarius. Code of Hygienic Practices for Milk and Milk Products. FAO. CAC/

[33] Codex Alimentarius. Recommended international code of practice general principles of

[34] Costa Dias MA, Sant'Ana AS, Cruz AG, José de Assis FF, Fernandes de Oliveira CA, Evandro B. On the implementation of good manufacturing practices in a small process-

International Dairy Federation; 1986. Retrieved from: http://www.idfa.org/

[thesis]. Master of Food Safety and Quality, Utah State University; 2013.

and goats. Revue Scientifique et Technique. 1997;**16**:482-488

food hygiene. CAC/RCP 1-1969, Rev. 4-2003. Rome. 2003:1-31

ing unity of mozzarella cheese in Brazil. Food Control. 2012;**24**:1-2

pasteurized milk. International Journal of Food Properties. 2006;**1**:523-524

Labneh (Concentrated yogurt). Journal of Dairy Science. 1999;**82**:682-689

ing storage. LWT—Food Science and Technology. 2003;**36**:407-414

2009;**26**(6):645-652. DOI: http://dx.doi.org/10.1016/j.fm. 2009.04.012

Mediterranean Health Journal. 2010;**16**(12):1221-1225

2012:**95**:521-532

396 Goat Science

and Preference. 2007;**18**:795-802

RCP 57-2004. Rome. 2004:1-32


**1. Introduction**

Integrated rice field aquaculture evolved from rice–fish coculture, and is playing a more and more important role in China, as the largest aquaculture producer in the world. It is also becoming one of the main freshwater aquaculture systems, in addition to ponds, lakes, reservoirs, streams, and other aquaculture systems, amounting to 10.52% of China s freshwater aquaculture production and 33.71% of the aquaculture area in 2020 [1] (Figure 1). China, the most populous country, is short of land resources and is also the biggest consumer of rice; therefore, food security is a priority of the Chinese government. The development of aquaculture by digging more ponds is strictly controlled by law. Therefore, integrated rice fields are getting more and more attention as a resource for increasing aquaculture production because of their properties of water conservation and using less land. This practice is normally adopted by individual small-scale farmers as an ideal use of land and an easy source of cheap, fresh, and convenient animal protein. It not only promotes sustainable agricultural and aquaculture development and farms and livelihoods, but also reduces poverty [2–4]. Consequently, during the past 40 years, both the production and area of integrated rice field aquaculture in China have significantly increased from 0.02 million t and 0.35 million ha in 1982 to 3.25 million t and 2.56 million ha in 2020, respectively [1,5] (Figure 2). Advances in ecology research, policy support, and aquaculture techniques for integrated rice–fish aquaculture are probably the main contributors to this achievement.

**Citation:** Yuan, J.; Liao, C.; Zhang, T.; Guo, C.; Liu, J. Advances in Ecology Research on Integrated Rice Field Aquaculture in China. *Water* **2022**, *14*, 2333. https://doi.org/10.3390/ w14152333

Academic Editors: Xiangli Tian and Li Li

Received: 26 May 2022 Accepted: 24 July 2022 Published: 28 July 2022

**Publisher's Note:** MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

**Copyright:** © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

**Figure 1.** Comparison of freshwater aquaculture production (**a**) and area (**b**) between rice fields and other main water bodies in China [1].

**Figure 2.** Changes in the aquaculture production and area in rice fields in China from 1950 to 2020 [1,5].

Integrated rice field aquaculture in China includes 25 different models [4]. In this paper, we systematically reviewed the advances in ecology research for the three most important systems in China, namely the rice–fish, rice–crab, and rice–crayfish coculture systems [6]. We also introduced the prospects for ecology research on integrated rice field aquaculture. This information could assist individual small-scale farmers to make better use of rice field space to produce safer aquatic and rice products at a lower cost and help aquaculture scientists to further study the ecology of this industry.

For this review, we searched for Chinese articles in the China National Knowledge Infrastructure database and English articles in the Web of Science database in 2022. We collected as many relevant pieces of literature as possible, and we only selected and referred to important published articles and books. Most of the information that was extracted included productive data (such as density, area, yield, survival rate, feed, and pesticide usage), aquaculture models, and advances in ecological research.

#### **2. Advances in Ecology Research on the Rice–Fish Coculture System**

The rice–fish coculture system is the most ancient integrated rice field aquaculture system in the world [2], and many fish species have been chosen for coculture, such as grass carp (*Ctenopharyngodon idella*), common carp (*Cyprinus carpio*) and its diverse strains, goldfish (*Carassius auratus*) and its diverse strains, swamp loach (*Misgurnus anguillicaudatus*), silver carp (*Hypophthalmichthys molitrix*), bighead carp (*Aristichthys nobilis*), and tilapias (*Oreochromis* sp.) [7,8]. Furthermore, ecology research in this system not only accelerates the development of the rice–fish aquaculture industry, but also lays the foundation for the formulation and development of other rice field integrated aquaculture systems.

#### *2.1. Establishment of the Rice–Fish Symbiosis Theory*

Ni [9] studied the population interactions between rice and fish in the coculture system based on biological and ecological traits in the late 1970s and early 1980s and put forward the Rice–Fish Symbiosis Theory in 1981. Ni and Wang suggested that rice is the main body in the rice field ecosystem and is also the dominant population, which absorbs solar energy, carbon dioxide, water, and other nutrients, and produces organic materials by photosynthesis and rice and straw for stakeholders. Moreover, plenty of weeds, phytoplankton, and photosynthetic bacteria in the field also conduct similar energy conversion, transportation, and storage as rice, but they also compete with rice for fertilizers, water, space, and solar energy without providing useful products for people [10]. Thus, the clearance of weeds in rice fields, which results in the loss of fertility and solar energy for rice, is imperative. Furthermore, plankton, bacteria, and other microorganisms are usually flushed away by irrigation, directly or indirectly causing the loss of fertility and solar energy [10]. Fish culture in rice fields can partially compensate for this loss. Fish in rice fields can directly or indirectly utilize weeds, zoobenthos, plankton, and detritus, decreasing competition with weeds for fertilizers, and utilizing the food and energy that cannot be utilized by rice [10]. In addition, nutrient loadings from fish can also provide nutrients for rice and plankton, and the CO2 released by fish can also be utilized by rice, weeds, and algae. Additionally, the fish may loosen the surface soil and improve the oxygen condition of the soil to promote the mineralization of organic matter and the release of nutrients [9]. In this ecosystem, rice and fish complement each other and both play an active role, promoting the cycle of materials inside the field, directing beneficial energy flow to both the rice and fish, and efficiently recycling the materials and energy in this coculture ecosystem [10].

The Rice–Fish Symbiosis Theory, although a qualitative description in theory, provides a theoretical base for the Chinese government to adopt specific extension policies for the development of this traditional practice with a long history. In 1983, the Health Commission of China listed fish culture in rice fields as an important measure for killing mosquitoes, and the Ministry of Agriculture, Husbandry, and Fisheries held the first nationwide "On Site Experience Exchange Conference on Fish Culture in Rice Fields" in Wenjiang County, Sichuan Province. Additionally, in 1984, the National Economic Commission of China listed fish culture in rice fields as a national technical development project and extended this technique to 18 provinces; and in 1987, the technical extension of fish culture in rice fields was accepted into the National Harvest Project and State Key Agricultural Extension Project. Then, in 1990, the Ministry of Agriculture held the second nationwide "On Site Experience Exchange Conference on Fish Culture in Rice Fields" in Chongqing [2]. Thus, the breakthrough of ecological theories for integrated rice field aquaculture won national policy support and accelerated the development of fish culture in rice fields in the 1980s (Figure 2).