Balancing Growth and Sustainability in China’s Carp Aquaculture: Practices, Policies, and Sustainability Pathways

Abstract

China leads global carp aquaculture (farming of species within the family Cyprinidae), producing 20 million tons annually in a sector shaped by favorable policies, infrastructure, and innovation. Carp farming in China is rooted in millennia of traditional practices and transformative post-1978 economic reforms. This review synthesizes the historical trajectory, technological advancements, policy frameworks, and sustainability challenges shaping China’s carp aquaculture sector. Historically, carp polyculture systems, developed during the Tang Dynasty (618–907 CE), laid the foundation for resource-efficient practices. Modern intensification, driven by state-led policies, genetic innovations, and feed-based systems, enabled unprecedented growth. However, rapid expansion has exacerbated environmental trade-offs, including nutrient pollution, habitat loss, and antibiotic resistance, while socioeconomic disparities, aging labor forces, and market volatility threaten sectoral resilience. Policy shifts since the 2000s prioritize ecological sustainability, exemplified by effluent regulations, wetland restoration, and green technologies. Despite progress, challenges persist in reconciling economic viability with environmental safeguards. Key success factors include long-term policy support, smallholder capacity building, vertically integrated supply chains, product differentiation, and adaptive management. With balanced policies emphasizing economic, social, and environmental sustainability, carp aquaculture can enhance domestic food and nutrition security. China’s experience showcases the potential of aquaculture to bolster food security but highlights the urgent need to harmonize productivity with ecological and social equity to ensure long-term resilience. Lessons from China’s model offer actionable insights for global aquaculture systems navigating similar sustainability imperatives.

1. Introduction

Aquatic food systems are critical in global food security, nutrition, and livelihoods, providing essential ecosystem services and contributing to healthy diets [1]. Aquaculture has emerged as a cornerstone of aquatic food production, surpassing capture fisheries for the first time in 2022 by contributing 51% of aquatic animal production [1]. Aquaculture’s role extends beyond mere production and supports rural livelihoods, mitigates poverty, and contributes to the United Nations Sustainable Development Goals (SDGs), particularly those related to zero hunger, clean water, and responsible consumption [2,3].

Among aquaculture’s diverse species, carps (Cyprinidae) represent the most commercially vital finfish group globally, accounting for one-third of total aquaculture production by volume [4]. Major species such as Chinese carps and Indian major carps are particularly prominent in Asian aquaculture systems, reflecting their historical and ongoing dominance in regional and global production [5,6]. Carp has been farmed for centuries across various regions, particularly in Asia nations, where carp farming supports food security and rural economies [7,8,9]. Its hardiness, adaptability, and rapid growth make it a highly valued species in aquaculture systems worldwide [10,11,12].

China is the leader in global aquaculture, producing 57% of total aquatic animal production in 2022 [1]. The country’s aquaculture sector has experienced transformative growth since the 1970s, driven by economic reforms, technological innovation, and strategic government support. With written records dating back to 475 BCE (Before Common Era), carp aquaculture is rooted in deep historical trajectories and cultural heritage, and represents China’s most important aquaculture species [13,14].

Despite China being the world’s largest aquaculture producer, with carps accounting for the highest proportion of the country’s aquaculture industry, there remains a notable gap in systematic reviews of China’s carp aquaculture development and its associated sustainability challenges. While historical and technical aspects of Chinese carp farming are well-documented, few studies holistically examine how policy frameworks, socioeconomic shifts, and ecological trade-offs have intersected to shape the industry’s evolution. Furthermore, the sustainability implications of China’s shift from traditional polyculture to intensive monoculture systems, such as nutrient pollution and dependence on commercial feeds, warrant deeper scrutiny to inform global best practices.

This review synthesizes literature through a narrative approach, drawing on historical records, policy documents, and contemporary studies to contextualize the evolution of China’s carp aquaculture. Literature was identified via Web of Science, Google Scholar, and China National Knowledge Infrastructure (CNKI) using keyword combinations (e.g., variants of ‘carp aquaculture China’ paired with ‘policy,’ ‘history,’ ‘production,’ ‘sustainability,’ or ‘value chain’). Priority was given to peer-reviewed articles in English and Chinese, as well as government reports, with emphasis placed on authoritative sources covering ecological, economic, and social dimensions. Production and trade statistics were primarily sourced from FAO FishStatJ and China’s National Fishery Statistics Yearbooks.

Building on this comprehensive literature base, we examine the practices, challenges, and policy frameworks underpinning China’s dominance in carp aquaculture, with three primary objectives: (1) synthesize historical and contemporary drivers of China’s carp aquaculture transition, (2) evaluate sustainability challenges across ecological, economic, and social domains, and (3) identify synergies between policy frameworks, technological innovations, and community practices that enhance sectoral resilience. By addressing these objectives, the review provides a comprehensive framework to reconcile growth with sustainability, offering actionable insights for policymakers, farmers, and researchers navigating similar challenges in global aquaculture systems. The findings serve as a critical reference for global aquaculture practices and offer opportunities to adapt China’s successful strategies while addressing its limitations to promote environmentally resilient and equitable sectoral growth worldwide.

2. Historical Overview and Current Status of China’s Carp Aquaculture

2.1. Historical Evolution of Carp Aquaculture in China

The history of carp (all cyprinid species) aquaculture in China is ancient and rich, reflecting thousands of years of development and innovation. The genetic diversity and adaptation of carp species in China are attributed to long-term geographical isolation, adaptation, and human domestication, resulting in a wealth of carp germplasm resources with diverse genetic characteristics [15]. Managed aquaculture of common carp (Cyprinus carpio) in China dates back to around 6000 BCE, as evidenced by fish bones from the Early Neolithic Jiahu site in Henan Province [16]. By 1100 BCE, common carp farming had already been established and conducted in earthen ponds. In the first book on aquaculture ever published in human history, Fan Lee on Pisciculture, or “The Chinese Fish Culture Classic”, described the methods for pond preparation, stocking, breeding, and management of common carp farming in 475 BCE [17]. This practice expanded significantly during the Tang dynasty (618–907 CE (Common Era)) to include other carp, with seeds primarily sourced from the Yangtze River. The polyculture of black carp (Mylopharyngodon piceus), grass carp (Ctenopharyngodon idella), silver carp (Hypophthalmichthys molitrix), and bighead carp (H. nobilis), conventionally referred to as the “four domesticated fishes” or “four family fishes”, has deep-seated cultural and societal significance since the Tang dynasty [18]. In the Song dynasty (960–1279 CE), fingerlings of these species began being transported to distant areas for farming [19]. Despite relying on wild seed supply, aquaculture remained a key enterprise for many households, leading to the widespread establishment of fish farming in China [19].

The period between 1949 and 1978 saw a continued dominance of pond fish farming, but a slowdown occurred due to a higher demand for fish seeds than could be supplied from the wild. This led to significant governmental intervention and innovation [19]. Since 1978, the start of economic reforms and opening up to the global market, the Chinese government has focused on promoting scientific research and technological advancements in carp farming, aiming to increase production and meet the growing demand for fish. Government-sponsored studies and research efforts led to breakthroughs, such as artificial propagation and reproductive techniques for major carps. The summary of farming management using eight words: water, seedling, feed, density, integration, rotation (stocking and harvesting), prevention, and governance, has become the pillars of a successful aquaculture industry in China [20,21]. A fast increase in carp production was witnessed since 1978.

Carp aquaculture in China has undergone significant transformations over the past two decades, moving from traditional integrated Chinese carp polyculture to species diversification and intensification of farming methods [20,22,23,24,25]. Traditional practices involved a semi-intensive polyculture system with up to nine species in polyculture with the major carp species included grass carp, bighead and silver carp, common and crucian carp, black carp, and other species like crucian carp (Carassius carassius) and Wuchang bream (Megalobrama amblycephala), utilizing natural pond fertilization and local feed sources. These practices were integrated with local agriculture and animal husbandry, where pond wastes and by-products were utilized as feeds and fertilizers [22]. This integrated system provided natural fertilization and feed for the carp from nutrients, plankton, and detritus [20,22,23,25]. Semi-intensive farming techniques were developed during the 1970s, using human-made ponds with supplemental feeding to increase production. This semi-intensive culture became widespread during the 1980s and 1990s [20,22,23]. Since the 1980s, Chinese carp aquaculture has intensified and commercialized, transitioning to high-density monoculture farming systems with manufactured feed, fertilizers, and chemicals [20,22,23,25,26].

2.2. China’s Dominance in Global Carp Aquaculture Production

China is the world’s largest producer of farmed carp (Figure 1a,b), accounting for over 62% of global carp production, with total output reaching 20.75 million metric tons in 2023, valued at over 57 billion USD [4]. Excluding aquatic plants, China’s carp production accounts for 22.1% of global aquaculture production [4]. It was estimated that over 90% of the production of fed “Chinese carps”, i.e., grass carp, Wuchang bream, black carp, crucian carp, and common carp, occurs in China [13,27].

Today, carp is still the most popular cultured fish in China, with grass carp being the most produced species, with an annual production of about 5.9 million tons in 2023 [28]. Meanwhile, carp species collectively constitute around half of all fish cultured in the country. The aquaculture of crucian carp, another dominant freshwater fish in China, has also become one of the largest aquaculture species in the country [28,29]. The country’s carp production is driven by the fact that the fish has low production costs and is tolerant of most climatic and environmental factors [10,13].

Carp aquaculture remains a vital economic activity and source of animal protein in China, and takes place across many Chinese provinces, with major producing areas in central and eastern China, including Hubei, Jiangsu, Guangdong, Hunan, Jiangxi, and Sichuan (Figure 2). Pond culture is the main culture model for carp, followed by reservoirs, lakes, rivers, channels, and paddy fields [13]. Most carp farming occurs in freshwater pond systems owned by small-scale farmers [22,25]. The following table provides an overview of the key carp aquaculture systems in China, detailing their characteristics, stocking densities, yields, regional prevalence, and recent developments (Table 1).

In recent years, the annual growth rate of carp farming production in China has been very high in earlier years of development due to a low base number, and quick production expansion in the 1980s and 1990s, thanks to the strong support from the Chinese government and continuous improvement in farming technologies. However, due to increased base numbers, environmental protection policies, changed consumers’ preferences to higher value products, environmental pollution, and resource shortages, the annual production growth rate of carp has been affected and has remained at a relatively low level, at 3–5%, since 2000 [13,24,26], before dropping to around 1% in the last five years.

Table 1. Major carp aquaculture systems in China.

Culture System	Characteristics & Practices	Typical Stocking Density and Yield	Regional Prevalence	Recent Developments
Traditional Pond Culture (Semi-intensive Polyculture)	Polyculture of 7–10 species (e.g., grass carp, silver carp, bighead carp, common carp, crucian carp, Wuchang bream) [30]. Relies on natural foods (plankton), supplemented by organic fertilizers (manure) and agricultural by-products [31,32]. Low external inputs; integrated nutrient cycling.	Density: Low to moderate (e.g., 300–600 grass carp/mu ≈ 4500–9000 fish/ha) [33]. Yield: 12–15 tons/ha [34,35].	Nationwide, especially in central/eastern provinces (e.g., Jiangsu, Hubei, Guangdong) [5,35].	Declining share due to intensification [5]. Modernized via partial pellet feeds and aeration [5,23].
Intensified Modern Pond Culture (Formula Feed-Based Polyculture)	“80:20 System”: 80% high-value carp (e.g., grass carp, common carp) fed pellets; 20% filter-feeders (silver/bighead carp) to consume plankton/wastes [23]. Aerated ponds; commercial feeds dominant [5,30]. Fewer species than traditional polyculture.	Density: High (e.g., 1.56 × 103 kg/hm2) (Dong, 2023 [36]). Yield: 15–40 tons/ha [5,34]. FCR: 1.8–2.3 for pellets [33].	Nationwide, especially in central/eastern provinces (e.g., Jiangsu, Hubei, Guangdong [5,33].	Dominant trend: Effluent treatment [5,37]. “Slimming carp” models (exercise + low feed) for premium markets [33].
Culture-Based Fisheries in Lakes/Reservoirs (Extensive, Stock Enhancement)	Stocking native carps (silver, bighead carp) into open waters for natural growth [38,39]. Minimal feeding/fertilization; relies on natural productivity [38]. Harvest via targeted fishing.	Density: Low stocking (species-specific data not provided). Yield: 743–921 kg/ha (reservoirs/lakes) [38].	Nationwide, especially large lakes (e.g., the Yangtze basin) and reservoirs [38,40].	Focus on environmental restoration [39]. Improved stock enhancement protocols for biodiversity [37].
Rice-Fish Integrated Systems	Co-culture of carps (e.g., common, crucian, grass carp) in flooded rice paddies [41]. Synergy: Fish control pests/weeds; rice provides shade/organic matter [41]. Extensive/semi-intensive.	Density: Variable, low (species-specific data not provided). Yield: ~2.4% of national freshwater production [33].	Nationwide, especially in Sichuan, Hunan, and Zhejiang [35,41].	Diversification (e.g., +crabs/prawns) [31]. Holistic models for sustainability [41].

Table 1. Major carp aquaculture systems in China.

Culture System	Characteristics & Practices	Typical Stocking Density and Yield	Regional Prevalence	Recent Developments
Traditional Pond Culture (Semi-intensive Polyculture)	Polyculture of 7–10 species (e.g., grass carp, silver carp, bighead carp, common carp, crucian carp, Wuchang bream) [30]. Relies on natural foods (plankton), supplemented by organic fertilizers (manure) and agricultural by-products [31,32]. Low external inputs; integrated nutrient cycling.	Density: Low to moderate (e.g., 300–600 grass carp/mu ≈ 4500–9000 fish/ha) [33]. Yield: 12–15 tons/ha [34,35].	Nationwide, especially in central/eastern provinces (e.g., Jiangsu, Hubei, Guangdong) [5,35].	Declining share due to intensification [5]. Modernized via partial pellet feeds and aeration [5,23].
Intensified Modern Pond Culture (Formula Feed-Based Polyculture)	“80:20 System”: 80% high-value carp (e.g., grass carp, common carp) fed pellets; 20% filter-feeders (silver/bighead carp) to consume plankton/wastes [23]. Aerated ponds; commercial feeds dominant [5,30]. Fewer species than traditional polyculture.	Density: High (e.g., 1.56 × 103 kg/hm2) (Dong, 2023 [36]). Yield: 15–40 tons/ha [5,34]. FCR: 1.8–2.3 for pellets [33].	Nationwide, especially in central/eastern provinces (e.g., Jiangsu, Hubei, Guangdong [5,33].	Dominant trend: Effluent treatment [5,37]. “Slimming carp” models (exercise + low feed) for premium markets [33].
Culture-Based Fisheries in Lakes/Reservoirs (Extensive, Stock Enhancement)	Stocking native carps (silver, bighead carp) into open waters for natural growth [38,39]. Minimal feeding/fertilization; relies on natural productivity [38]. Harvest via targeted fishing.	Density: Low stocking (species-specific data not provided). Yield: 743–921 kg/ha (reservoirs/lakes) [38].	Nationwide, especially large lakes (e.g., the Yangtze basin) and reservoirs [38,40].	Focus on environmental restoration [39]. Improved stock enhancement protocols for biodiversity [37].
Rice-Fish Integrated Systems	Co-culture of carps (e.g., common, crucian, grass carp) in flooded rice paddies [41]. Synergy: Fish control pests/weeds; rice provides shade/organic matter [41]. Extensive/semi-intensive.	Density: Variable, low (species-specific data not provided). Yield: ~2.4% of national freshwater production [33].	Nationwide, especially in Sichuan, Hunan, and Zhejiang [35,41].	Diversification (e.g., +crabs/prawns) [31]. Holistic models for sustainability [41].

Figure 2. China’s carp production by provinces and species in 2023. (a) All carp; (b) Black carp; (c) Grass carp; (d) Silver carp; (e) Bighead carp; (f) Common carp; (g) Crucian carp; (h) Bream. Data map produced by the Standard map service system at http://bzdt.ch.mnr.gov.cn/index.html (accessed on 25 April 2025). The two-letter abbreviations for Chinese provincial-level administrative divisions follow the ISO 3166-2: CN Standard [42]. Complete list: AH: Anhui; FJ: Fujian; GS: Gansu; GD: Guangdong; GZ: Guizhou; HI: Hainan; HE: Hebei; HA: Henan; HL: Heilongjiang; HB: Hubei; HN: Hunan; JS: Jiangsu; JX: Jiangxi; JL: Jilin; LN: Liaoning; QH: Qinghai; SD: Shandong; SX: Shanxi; SN: Shaanxi; SC: Sichuan; YN: Yunnan; ZJ: Zhejiang; GX: Guangxi; NM: Inner Mongolia; NX: Ningxia; XZ: Xizang (Tibet); XJ: Xinjiang; BJ: Beijing; CQ: Chongqing; SH: Shanghai; TJ: Tianjin; HK: Hong Kong; MO: Macau; TW: Taiwan. Data source from reference [28].

Figure 2. China’s carp production by provinces and species in 2023. (a) All carp; (b) Black carp; (c) Grass carp; (d) Silver carp; (e) Bighead carp; (f) Common carp; (g) Crucian carp; (h) Bream. Data map produced by the Standard map service system at http://bzdt.ch.mnr.gov.cn/index.html (accessed on 25 April 2025). The two-letter abbreviations for Chinese provincial-level administrative divisions follow the ISO 3166-2: CN Standard [42]. Complete list: AH: Anhui; FJ: Fujian; GS: Gansu; GD: Guangdong; GZ: Guizhou; HI: Hainan; HE: Hebei; HA: Henan; HL: Heilongjiang; HB: Hubei; HN: Hunan; JS: Jiangsu; JX: Jiangxi; JL: Jilin; LN: Liaoning; QH: Qinghai; SD: Shandong; SX: Shanxi; SN: Shaanxi; SC: Sichuan; YN: Yunnan; ZJ: Zhejiang; GX: Guangxi; NM: Inner Mongolia; NX: Ningxia; XZ: Xizang (Tibet); XJ: Xinjiang; BJ: Beijing; CQ: Chongqing; SH: Shanghai; TJ: Tianjin; HK: Hong Kong; MO: Macau; TW: Taiwan. Data source from reference [28].

2.3. Value Chain

China’s carp farming value chain typically involves several key stages and multiple actors, including farmers, suppliers, traders, and consumers (Figure 3), ensuring a steady supply of carp from hatchery to table [43,44,45]. China’s carp aquaculture value chain begins with specialized hatcheries breeding fingerlings using quality broodstock to induce spawning, followed by nursery rearing in ponds or tanks for optimal growth. Fingerlings transition to grow-out ponds, cages, or raceways managed predominantly by small-scale farmers, supported by cooperatives offering technical training and market access [46]. Feed is supplied by feed mills, often constituting 60% of production costs [47]. Agrochemicals such as fertilizers and antimicrobials enhance growth and disease control, but disease outbreaks remain a persistent risk [48]. Market-sized carp are harvested via pond draining or seine nets, with most sold live and minimal processing for distribution. Products reach consumers through wet markets, supermarkets, restaurants, and online platforms [49], including value-added items like “Sour boiled fish fillets” made from grass carp. As carp is China’s most consumed freshwater fish, they hold cultural and dietary significance rooted in historical practices [50]. Academic institutions drive innovation in genetics and sustainability, building on centuries of domestication [51], while government subsidies, research funding, and extension services contribute to sectoral growth.

Figure 3. Grass carp aquaculture value chain in China. Modified from reference [52].

Figure 3. Grass carp aquaculture value chain in China. Modified from reference [52].

2.4. Policy Frameworks and Infrastructure

China’s aquaculture sector has undergone transformative growth since the 1970s, driven by economic reforms, technological innovation, and strategic government support. Emerging as the world’s largest producer and consumer of aquaculture products, the sector significantly contributes to GDP, food security, and export revenue [19,53], although export revenue from carp remains limited. The 1978 economic reforms stimulated a shift from capture fisheries to intensive aquaculture, with output surpassing wild-caught production by 1993. Government policies and support programs, such as the “Torch Programme” and “Rich Harvesting Programme,” played a crucial role in the expansion of carp farming and aquaculture extension projects nationwide [19]. This transition was fueled by policies granting producers autonomy over production and marketing decisions, alongside rapid annual growth (over 11% in the 1980s–1990s) through farming area expansion and technological adoption [19,20,54]. Growth stabilized post-2000 (3–7%) as environmental regulations and a maturing production base took hold, declining further to under 3% after 2015 along with the prioritization of environmental sustainability [26].

Three distinct policy phases have shaped the sector’s trajectory. Pre-2000, the focus was on rapid expansion through subsidies, research funding, and systemic support for critical inputs like seed, feed, and machinery [13,19,55]. Post-2000, policies balanced productivity with sustainability, formalized by the Fisheries Law and regulations on food safety, biosecurity, and environmental protection [56,57]. After 2012, ecological priorities dominated, exemplified by the 2016 “reducing volume and increasing efficiency” policy and the 2019 Several Opinions on Accelerating Green Development, which aligned aquaculture with national green development goals [36,58]. These shifts were institutionalized through Five-Year Plans for National Fishery Development, particularly from the 11th Five-Year Plan (2006) onward, emphasizing resource conservation, structural adjustment, and ecological integrity [26,59,60].

Financial and institutional reforms underpinned this transition. Post-1978 economic autonomy incentivized producers, while subsidies and quasi-property rights (e.g., long-term use rights for farm lands and communal ponds) enabled investments in intensification [61,62]. Public funding programs and green subsidies further supported value chain development, though regulatory restrictions sometimes hindered the effectiveness of green finance [63,64].

China’s aquaculture success is also anchored in robust infrastructure and technical innovation. Carp farming especially relies on hatcheries and nurseries governed by the national aquatic germplasm system under the Fisheries Law [37,65]. Feed mills, cold-chain logistics, and rural infrastructure such as roads, electricity, and irrigation facilitated intensification and market connectivity [13,19,20,66]. Collaborative networks between research institutions and farmers optimized practices like stocking density and disease control, supported by extension services and demonstration zones [26,67]. This infrastructure created a virtuous cycle, where aquaculture revenues funded rural development.

Policies now navigate dual objectives, enabling growth through incentives while imposing environmental safeguards. Direct subsidies, R&D funding, and technical training enhance competitiveness, yet stricter water use, nutrient discharge, and lake aquaculture regulations have increased compliance costs and reduced aquaculture farming areas [13,68]. The “ecological civilization” framework prioritizes green development, reflected in the 14th Five-Year Plan’s emphasis on quality, innovation, and resource efficiency [69,70]. However, challenges persist, including enforcement gaps in food safety, inter-agency coordination, and sustainability trade-offs from rapid intensification [13,26].

To reconcile these tensions, the Ministry of Agriculture and Rural Affairs (MARA) promotes innovation-driven strategies, advanced technologies, and international collaboration to address systemic issues in seed quality, feed efficiency, and ecological branding [63]. While China’s aquaculture model demonstrates the synergy of policy, infrastructure, and innovation, ongoing adaptation remains critical to harmonize economic and ecological goals for long-term resilience.

2.5. Technological Advancements and Intensification

The technology upgrades transformed carp farming in China from a traditional extensive system to a highly intensive industry with rising productivity. China has been a major player in the development of science and technology in aquaculture production. Improved selective breeding programs, disease management, and nutrition have allowed Chinese carp farms to maximize production.

Intensification and commercialization of carp culture have increased in recent decades to boost productivity and meet rising domestic demand [13,24]. Some traditional farming practices have gradually disappeared in China, such as the mulberry-fish ponds, sugar cane-fish ponds, and lotus-fish ponds production systems have been declining since the 1990s [71]. Although the internal circulation of nutrients and energy in these systems can greatly reduce environmental impacts [72], they have been replaced by new intensive production methods due to economic factors such as rising labor costs. The carp farming industry has evolved from low-output, extensive aquaculture systems in the 1970s, with no additional feed input, to intensive systems using supplementary feed [47]. Since 2000, carp farming in China transitioned into a new phase based primarily on feed-based systems, shifting from traditional extensive farming to more intensive cultivation, often focused on single high-value species, supplemented by a few carp species [22,23,24,25,59,73]. Using grass from ponds and the surrounding environment as fish feed was common [74]; however, grass carp culture in China no longer uses fresh grasses for feed, and all carp are fed with pellet feeds [36]. Stocking densities increased from around 5000 fish/ha in the 1980s to over 20,000 fish/ha today. Carp growth varies by species, farming system, and region. Bighead carp grows fastest at 15 g/day, while grass and silver carps average 6–7 g/day [75]. In subtropical conditions with semi-intensive farming, silver carp, bighead carp, and grass carp reach 4–5 kg, 8–11 kg, and 10 kg, respectively, after three years, while in temperate regions like Shanghai, grass carp reaches only 2.5 kg after the same period [75]. This intensification and more inputs like feed and aeration led to higher yields per hectare. Average per-hectare yields in Chinese aquaculture have dramatically increased from 1500 kg in the 1990s to 4600 kg in 2013 [76], and further surged to 7830 kg in 2022 [77]. The traditional cyprinid carp farming yield in the Yangtze River basin has remained stable at 15,000–22,500 kg/ha [78]. Intensification and the use of feeds contributed to the epic 10-time increase in freshwater aquaculture production in China in just 20 years [79].

Improved pond construction, aerators, and automatic feeders allow higher stocking densities. Internet of Things technologies help remotely monitor conditions [80,81]. The renovation and standardization of aquaculture facilities have positively contributed to these high yields. By 2010, more than 670,000 hectares of standardized aquaculture ponds had been restructured, and over 1700 standardized and health-focused aquaculture demonstration sites (or zones) were established [82].

Technological breakthroughs such as artificial breeding technology have been pivotal [20,54,65,83,84]. Following the first successful artificial propagation of silver carp and bighead carp in 1958 using pituitary extract and HCG, hatchery fry production surged to 1.5 trillion in 2023, effectively eliminating dependence on river-caught seed and enabling year-round, region-wide stocking [19,28]. Novel strains were developed using methods like traditional line selection, crossbreeding, hybridization, chromosome set manipulation, and molecular markers-assisted selection [15,37,84,85]. The genetic evaluation of carp breeding programs has been a cornerstone of this industry. China established 240 certified aquaculture new varieties by 2021, with carp as a focal species [86]. These programs have made significant progress in breeding carps with increased harvest body weight and the introduction of fast-growing strains [84,87]. For example, the FFRC strain of common carp achieved a 28% cumulative genetic gain in growth traits, with field trials showing 20–39% higher productivity than non-improved strains [88].

Balanced pelleted feeds have become mainstream and replaced traditional bran, plant, and agricultural products, formulated with optimal protein, lipids, vitamins, and minerals. There is also a trend of increased use of agricultural by-products like soybean and rapeseed meals as protein sources to replace fishmeal. Fishmeal usage in feed declined from 10% in carp feed to about 1% [89]. Immunostimulants, prebiotics, and probiotics are added to boost health and digestion. Automatic feeders allow controlled feeding rates tailored to fish growth, and sensor-based systems trigger feeding only when fish are active, reducing waste [80,81].

Efforts have been made to promote the green development of aquaculture in China, featuring low input and high output, emphasizing the importance of ecological efficiency [90]. Suggestions include improving green subsidy policies, enhancing supervision and service, strengthening scientific and technological innovation, and using unique local advantages [91]. Holistic approaches have also been proposed to improve the sustainability of major aquaculture production systems in China [92].

3. Economy, Market, and Financing

3.1. Market Dynamics

Carp aquaculture provides affordable, protein-rich aquatic products crucial for urban and rural nutrition in China [93], and as a dietary staple, significantly contributes to national food security due to carp’s adaptability, rapid growth, and market demand [13,94,95]. Carp are valued not only for their accessibility but also for their nutritional benefits, including omega-3 fatty acids derived from feed and bioconversion in semi-intensive systems, enhancing consumer health [96].

Carp dominate China’s domestic market due to their flavor, cost-effectiveness, and cultural preference for bony fish [6,97]. However, rising incomes and urbanization have spurred diversification into high-value species (e.g., shrimp, crab) in coastal regions, reflecting shifting consumer tastes toward premium aquatic foods [13,24,98]. Despite this, carp remain central to local diets, with 99% of production consumed domestically, primarily sold live to meet perceptions of freshness [13,99].

Exports are minimal, only ~50,000 tons annually, mostly live carp to Hong Kong (Figure 4a,b), while domestic markets thrive through wet markets, supermarkets, and restaurants. Challenges persist, however, including fragmented small-scale producers, unbalanced pricing power among wholesalers and farmers, and inconsistent standards that hinder quality control and market efficiency [93]. Enhanced regulatory oversight and integrated distribution systems are critical to addressing market inefficiencies. Establishing public price platforms and standardizing harvesting and processing practices could stabilize prices and improve product quality [93]. Concurrently, promoting sustainable intensification and diversification while retaining the carp’s cultural and nutritional role will ensure resilience.

3.2. Evolution of Financing Mechanisms

China’s carp farming industry has evolved through dynamic financing mechanisms, transitioning from state-led support to diversified private-sector participation. Beginning in the 1970s–1980s, the government prioritized aquaculture as part of post-1978 economic reforms, establishing public hatcheries to supply low-cost fry and subsidizing machinery like aerators to reduce production costs [19]. These initiatives aimed to bolster food security, rural employment, and income, with fiscal support extending to infrastructure development and insurance schemes [100].

Initially constrained by reliance on personal savings and informal loans, farmers gained access to formal financing in the 1980s–1990s through rural credit cooperatives, which funded fixed assets such as ponds. By the 2000s, joint-stock banks and private lenders recognized aquaculture’s potential, expanding loans for commercial-scale operations. Innovations like online finance platforms further eased credit access, while institutions such as the Agricultural Bank of China introduced tailored products like the Personal Business Loan for Farmers to support scaled production [101]. Concurrently, feed and chemical companies leveraged formal investment channels to drive sector growth.

The 1990s marked a shift toward technology adoption, with bank loans enabling investments in high-quality seed, automated feeders, and aerators. Government-funded breeding programs enhanced disease resistance and growth rates, while subsidies for cold-chain infrastructure improved market integration [13]. Post-2000, private capital accelerated IT integration and precision farming tools, fostering efficiency gains.

Despite its current high production volume, the carp aquaculture sector in China still holds significant untapped potential for growth. Emerging technologies in waste management, renewable energy, and genetic improvement promise enhanced sustainability and profitability, supported by blended public–private financing models [13,68,80]. Thus, China’s carp farming exemplifies a financing trajectory from state-driven subsidies to a hybrid ecosystem, balancing innovation with resilience in a rapidly modernizing industry.

3.3. Economic Viability and Investment Dynamics

China’s carp farming industry, which has expanded rapidly since the 1980s due to technological advancements and supportive policies, faces evolving economic dynamics shaped by production efficiency, market trends, and regulatory pressures. The payback period for initial investments hinges on factors such as feed efficiency, disease management, and market prices, with efficient practices shortening returns. In contrast, poor management or price volatility extends them [47]. Historically, intensification boosted yields. However, profitability is now challenged by rising input costs, stringent environmental regulations, and shifting consumer preferences toward diversified aquatic products [13,63]. Carp’s low market value (USD 2–3/kg, Figure 5) and price volatility affect profit margins, while rising costs for feed, labor, and compliance with environmental regulations limit profitability [13,102]. Stricter environmental regulations constraining carp farming have also attracted investments aiming to fill supply gaps. Farmers increasingly adopt risk-mitigation strategies, such as reverting to traditional dyke-crop systems or diversifying production, to balance costs and labor [13]. Nonetheless, carp remain low-value commodities needing to compete with small producers, limiting investment returns.

Feed and chemical companies’ payback periods are usually more explicit due to the capital-intensive nature of these industries and the need for precise financial planning to manage high upfront investments and regulatory compliance [103,104]. While small-scale farms with minimal investment continue to dominate carp production [78], large private and corporate investments have targeted supply chain sectors such as seed production, feed manufacturing, and processing to enhance efficiency and meet market demands [24,105].

4. Environmental Sustainability and Resilience

4.1. Environmental Impacts

The large-scale production and intensification of carp farming, driven by monoculture practices and formulated feeds, has exacerbated nutrient pollution in China’s water systems. Effluents from ponds are often rich in nitrogen, phosphorus, and organic matter and exceed eutrophication thresholds, degrading water quality in critical areas like Taihu Lake [106,107]. This nutrient enrichment depletes dissolved oxygen, fuels algal blooms, and disrupts aquatic ecosystems [108,109,110,111]. Overfeeding and insufficient effluent treatment further compound these issues [112,113].

As the world’s top carp and aquaculture producer, China’s industry has driven significant land-use changes, particularly through the expansion of freshwater ponds. The expansion of carp aquaculture since the 1950s has converted natural wetlands and floodplains into ponds, impacting the biodiversity and ecosystem services these wetlands provide [114]. Following rapid post-1978 development, the inland fish pond area grew by nearly 150% from 1983 to 2003, primarily due to the conversion of agricultural land and flood-prone areas [13,22]. Remote monitoring highlights extensive aquaculture encroachment in coastal regions like the Yellow River Delta, where farmland has been replaced by ponds [115]. Land Use and Land Cover Change (LULCC) studies in Qianjiang City reveal socioeconomic drivers shifting land use: while farmland dominated (>70% from 1990–2022), built-up and aquaculture areas grew steadily [116]. However, recent policies have prohibited converting crop land and wetland to ponds, and even rewilded some areas back into wetlands [13,94].

Carp aquaculture growth is limited by land and freshwater availability. Fed aquaculture’s resource demands are amplified by feed production, which exceeds direct grow-out footprints in land and water use [10]. Water scarcity, exacerbated by uneven distribution and population pressure [117], is compounded by economic growth-driven pollution, now a top government priority [118]. Climate change could also exacerbate these pressures, as warming amplifies evaporation and disrupts precipitation patterns, sea-level rise, and salinizing groundwater in coastal provinces could restrict freshwater availability and intensify competition with agriculture, and salinity intrusion reduces growth rates in freshwater carps [119,120]. Carp polyculture ponds require high water inputs, discharging 50–80% as effluent, which is a major environmental concern [121,122,123]. Technical innovations around recirculation and polyculture integration offer means for carp farming to enhance water use efficiency; however, customized engineering and management protocols are necessary for adoption feasibility [58]. Meanwhile, adoption requires tailored protocols to balance feasibility with environmental goals, particularly in mitigating aquaculture’s role in eutrophication through improved effluent management. Beyond farm effluent discharge, Chinese carp aquaculture also faces environmental challenges from contaminated inflow water sources, for example, irrigation water drawn from adjacent agricultural areas, which could introduce pollutants, including heavy metals and excess nutrients, into aquaculture ponds [124,125].

Intensive farming also relies on agrochemicals and antibiotics, leading to residues of antimicrobials and resistant bacteria in waterways [126]. These contaminants threaten farmed and wild fish populations, as seen in grass carp systems, where pathogens spread to ecosystems [127,128].

Furthermore, carp aquaculture could pose a potential threat to native carp populations. Escaped non-native mrigal carp (Cirrhinus mrigala) outcompete indigenous species like mud carp, altering genetic diversity and ecosystem balance [129]. Hybridization and ploidy variations in crucian carp further stress native populations [130]. Reliance on wild-caught fishmeal for feed could also exacerbate overfishing [24,59].

4.2. Sustainability Efforts

In response to environmental concerns, the Chinese freshwater aquaculture sector has introduced significant paradigm changes, such as prohibiting fertilization in large water bodies such as lakes and reservoirs and setting stringent standards on nutrients in effluent [131]. The Chinese government has implemented policies and regulations to promote sustainable aquaculture practices, including measures to protect water resources, reduce pollution, and promote environmentally friendly technologies. Environmental legislation, such as banning cage and pen culture in lakes and reservoirs (affecting ~7% of production in 2018), has reduced carp farming areas and promoted rewilding and stricter effluent standards [13,132]. Concurrently, policies like wetland restoration and stricter environmental regulations reduced coastal pond areas by 13.21% (2016–2021), prioritizing ecological balance over aquaculture expansion [133]. On some occasions, farmers are de-intensifying by reducing commercial aquafeed inputs and reverting to traditional dyke-crop culture to optimize input costs, labor, and risk management [13]. Technological innovations like renewable energy, biofloc systems, constructed wetlands for effluent treatment [58], pollution-free certification, and financial assistance are prioritized [63].

Polyculture, a traditional Chinese aquaculture method, involves cultivating multiple fish species to efficiently utilize resources, with waste from one species becoming inputs for another [134]. Most carp farming in China combines omnivorous (common carp, crucian carp), herbivorous (grass carp), and filter-feeding species (silver carp, bighead carp), minimizing reliance on high-quality feed and fishmeal [10,59,135]. This system utilizes semi-intensive methods with natural food produced from pond fertilization, supplemented with various locally available feeds, and often integrates agriculture and animal husbandry [22,54,136,137]. Today, around 80% of China’s freshwater aquaculture uses polyculture [138], enhancing productivity, resource efficiency, and environmental resilience based on the ‘portfolio effect’ [23,139,140,141]. Filter-feeding carps improve water quality by assimilating nutrients [24,142], while optimized feeding strategies and treatment systems further reduce pollution [81,143].

In large water bodies like Lake Qiandaohu, filter-feeding carps are stocked for ecosystem remediation. Silver and bighead carp control cyanobacteria blooms, improving water quality and enabling the lake to serve as a drinking source for 15 million people [26,144,145]. This model of restorative aquaculture highlights the dual provisioning and cultural ecosystem services of such systems [146,147,148].

Carp farming is deeply integrated with agriculture, exemplified by traditional rice-fish systems that hold cultural and ecological significance [149]. Carp farming in rice-fish systems, practiced in China for millennia, is a globally recognized agricultural heritage [149,150,151]. Synergies with agriculture, animal husbandry, and cottage industries enable waste reuse (e.g., distillery byproducts) as supplemental feeds, reducing reliance on external inputs [22]. These systems reduce chemical inputs, conserve biodiversity, and produce both rice and aquatic protein [149,152,153]. Over 25 million hectares of China’s rice paddies are suitable for aquaculture [154], although rice-fish systems have shifted away from carps toward high-value species such as Chinese soft-shelled turtles (Pelodiscus sinensis), crayfish (Procambarus clarkii), and mitten crabs (Eriocheir sinensis) [54]. This diversification aligns with local economic demands and has driven growth in production, enhancing economic benefits while maintaining sustainability [155,156], and the proportion of aquatic food from rice-fish systems in China’s total inland aquaculture rose from 5.7% to 11.8% over the past decade [157].

Some farmers are diversifying species and de-intensifying practices to meet local demand. Emphasis is shifting to green technologies for major species, including biofloc systems [158,159], constructed wetlands [58], and food waste recycling [135]. Pollution-free certification and stricter effluent regulations align carp aquaculture with sustainability goals [63].

4.3. Resilience and Risk Management

Carp aquaculture in China faces multifaceted risks, ranging from environmental to socioeconomic challenges. Environmental degradation, driven by intensive aquaculture practices, has emerged as a critical concern. Pollution from high water-exchange systems, eutrophication, and habitat destruction has strained water resources and exacerbated coastal pollution [160,161]. These issues, compounded by conflicts between production and environmental regulations (e.g., Water Resource Protection Law), have triggered booms and bust cycles of fish and shrimp farming and public scrutiny [23,162,163,164,165]. Natural disasters such as floods, exacerbated by climate change, threaten inland facilities, particularly in regions like the Pearl River Delta, where urbanization and water management practices have heightened vulnerability. Disease outbreaks further amplify risks. Intensive farming’s homogeneity facilitates pathogen spread, with diseases like grass carp hemorrhagic disease and Cyprinid herpesvirus causing annual losses exceeding 50 million USD [128,166]. Weak regulatory oversight and limited vaccine adoption exacerbate vulnerabilities, while poor-quality seedstock and unassessed stock-enhancement activities threaten native biodiversity [167,168].

To counter climate impacts, China’s carp aquaculture has adopted adaptive strategies, emphasizing flexibility and innovation. Farmers optimize input-labor trade-offs and adopt selective breeding, mechanization, and technical upgrades to enhance efficiency [59,94,133,169]. Modified farming systems, renewable energy integration, and biofloc technology enhance resource efficiency and reduce environmental footprints [63]. Farmers are increasingly diversifying livelihoods, blending traditional aquaculture methods with modern practices to optimize cost-labor trade-offs and mitigate climate risks [13,170]. Genetic diversity plays a pivotal role; selective breeding programs have developed strains resistant to temperature extremes, hypoxia, and diseases, ensuring stable yields while with changing conditions [120,171]. Disease management through biosecurity, vaccines, and data-driven mortality modeling [172] can reduce losses. Biosecurity investments such as sterilization infrastructure, wildlife barriers, and vaccines further curtail disease transmission [173,174]. The Chinese government has been promoting sustainable aquaculture practices and has implemented regulations to control the use of antibiotics in aquaculture due to concerns about antibiotic resistance [175]. Diversification into higher-value species, vertical supply chain integration, and innovative branding enhance market resilience. Diversification of farming practices, including polyculture and reduced input dependency, emerged as a buffer against such shocks, enabling farmers to balance risks and maintain productivity [13]. Climate adaptation measures, such as proper modifications in farming systems and infrastructure facilities, could improve the resilience of the aquaculture industry [9]. The industry continues to adapt through hybrid strategies such as leveraging technological advancements and policy alignment to reconcile productivity with sustainability, ensuring resilience amid evolving ecological and economic landscapes.

5. Socioeconomic Sustainability

5.1. Socioeconomic Dimensions and Sustainability Challenges

Historically, carp farming has been integral to agricultural development, shaping public perceptions and sustaining rural livelihoods [18]. Today, carp aquaculture remains vital to China’s rural economy, providing affordable protein and income diversification opportunities. Economic reforms have spurred rural households to adopt aquaculture as part of broader income-generating strategies [176]. The Household Contract Responsibility System (HCRS) further catalyzed growth by granting small-scale farmers land tenure rights, boosting productivity, and market integration [177,178].

Local communities actively participate in aquaculture, adopting practices like the conversion of traditional rice paddies into crayfish-fish polyculture to reduce greenhouse gas emissions while increasing profits [179]. However, industrial intensification has unevenly distributed risks and rewards, with smallholders often lacking access to advanced technologies or equitable policies [63]. The rapid intensification of carp farming could also threaten its ecological and economic sustainability. Declining productivity due to disease, overcrowding, and pollution jeopardizes rural livelihoods [161]. Addressing these challenges requires adopting low-impact technologies (e.g., improved biosecurity, waste management), stricter chemical regulations, and equitable policies to rebuild public confidence [63].

Food safety issues, including chemical misuse and lax oversight, have eroded consumer trust in carp products [180,181]. Intensive farming practices also contribute to water pollution and eutrophication, raising public concerns about long-term ecological harm [161]. Studies highlight antibiotic resistance in aquaculture systems as an emerging environmental and health risk [175].

Animal welfare considerations in China’s carp aquaculture remain an emerging area with limited regulatory frameworks compared to Western standards. Current national policies prioritize food safety, pollution control, and resource efficiency [92,131], with limited codification of welfare-specific practices for cyprinids. The adoption of international certification schemes incorporating welfare criteria is primarily observed in export-oriented sectors like tilapia or shrimp [35] and has not significantly permeated the domestic carp market. Consumer awareness of animal welfare in aquaculture remains limited, with purchasing decisions primarily driven by price, freshness, and food safety rather than welfare certifications [98,182]. This gap represents an important frontier for social sustainability, particularly as global markets and ethical frameworks increasingly emphasize welfare.

5.2. Labor Structure and Workforce Challenges

Aquaculture is a pillar of rural economic growth, diversifying livelihoods and alleviating poverty. Carp aquaculture in China predominantly operates as small-scale family enterprises, with most farms relying heavily on unpaid household labor. In 2017, fishers and aquaculture farmers earned 18,452 CNY annually, surpassing the rural average of 13,432 CNY [26]. The family-based production model creates unique labor dynamics where multiple generations participate in pond management, feeding operations, and harvest activities. The New Rural Cooperative Medical System (NRCMS), established in 2003, now provides health insurance to mitigate occupational risks [183,184].

China’s aquaculture workforce is aging; surveys show that carp farmers are 48 years old, with only 7.5% under 35 [185]. This aging trend reflects broader patterns in Chinese agriculture, where agricultural laborers have declined from 390.98 million in 1991 to 177.15 million in 2020, with only 19% of agricultural laborers under age 40 in 2020 [186,187]. Youth increasingly reject aquaculture due to low income potential, preferring urban employment [185]. This trend threatens sector sustainability, compounded by informal working conditions and migration of laborers to cities and coastal areas [188]. The migration of young people contributes to the aging of the agricultural workforce, forcing many carp farms to operate with reduced labor capacity or rely on seasonal workers during critical periods such as harvesting and pond maintenance.

Gender dynamics in carp farming reflect traditional rural labor patterns, with women playing essential roles in daily operations, including feeding, pond monitoring, and record-keeping. However, their contributions are constrained by limited access to resources, technology, and markets, and low literacy rates [189]. Rural women increasingly pursue off-farm work, aided by digital connectivity [190]. Addressing these barriers could enhance gender equity and sector productivity.

China’s strict enforcement of compulsory education and labor laws has minimized child labor in aquaculture. The nine-year schooling mandate (ages 6–15) is reinforced by free primary/middle education and penalties under the Law on the Protection of Minors [191,192], together with poverty reduction and urbanization [193,194] reducing reliance on child labor in rural enterprises, including carp farming.

5.3. Justice, Equity, Diversity, and Inclusion (JEDI) Gaps and Opportunities

Justice, equity, diversity, and inclusion (JEDI) are increasingly prioritized in global aquaculture, yet the explicit integration of these principles into China’s carp aquaculture remains understudied. While existing literature focuses on biological, genetic, and economic aspects (e.g., COVID-19 impacts), social dimensions like equity and gender inclusion are often overlooked [49,53]. Pilot initiatives, such as province-level agricultural insurance programs for low-income carp farmers, demonstrate how targeted reforms can enhance equity for marginalized groups [195].

China has lifted over 800 million people out of extreme poverty in four decades, driven by multifaceted policies: education, healthcare, infrastructure investments, and skill development [196,197]. Aquaculture played an important role in this effort; for example, the carp value chain sustains millions of livelihoods, spanning hatcheries, feed production, farming, and processing [13,198]. Government-led poverty reduction programs in remote regions (e.g., 32 southwestern counties) have proven effective and efficient [199]. Ethnic minorities and rural communities benefit from legally protected rights and tailored support, ensuring equitable participation in economic growth [200].

The Chinese government has implemented equity-focused policies for vulnerable groups. Policies address fertility challenges for women and high childcare costs. However, societal reliance on familial financial and caregiving support persists [201]. Land fragmentation reduces agricultural productivity, pushing young workers toward non-farm jobs. Government strategies like land consolidation and rural industry integration aim to retain youth in farming [202]. Organizational government support (e.g., for environmental improvements) strengthens rural participation, with farmers responding more positively to relational than transactional aid [203].

The intensification of inland aquaculture requires context-specific measures, such as concessionary taxation, subsidies, and environmental management, to harmonize rural development and address income disparities [204]. Aligning carp aquaculture with China’s broader equity frameworks (e.g., insurance programs, poverty alleviation) could bridge the JEDI gap while enhancing sector sustainability.

6. Discussion

The massive scale and rapid growth of China’s carp aquaculture sector owes much to favorable policies, state-led infrastructure investments, innovation ecosystems, and community adaptation shaped over decades of public and private efforts. The evolution of China’s carp aquaculture reveals three interconnected patterns that distinguish it from other global aquaculture systems.

First, the institutional-technological co-evolution pattern demonstrates how policy frameworks and technological innovations reinforced each other cyclically. Unlike linear technology adoption models, China’s experience shows that institutional reforms (such as land use rights and the Household Contract Responsibility System) created enabling conditions for technological uptake [177,178], which, in turn, generated economic returns that justified further policy support and research investment. The integration of land tenure security with production incentives proved essential for enabling farmer investment in long-term improvements [61,62]. China’s success in scaling appropriate technologies through demonstration zones and extension services [26,67] offers a replicable model for other countries seeking to modernize traditional aquaculture systems. China’s state-led infrastructure investment approach also enabled rapid scaling that circumvented typical capital constraints faced by smallholder farmers elsewhere [13,19,20,66].

Second, the sustainability transition paradox emerges as a unique pattern where intensification initially degraded environmental conditions [106,107,108,109,110,111] but subsequently catalyzed more sophisticated sustainability innovations. Pollution pressures became internal drivers for polyculture optimization [134], integrated systems development [149,152], and precision management technologies [80,81]. China’s “develop first, regulate later” sequencing approach demonstrates that rapid expansion followed by environmental correction [36,58] created both larger-scale environmental challenges and more comprehensive policy responses [149,152]. China’s polyculture maintenance [138] distinguishes it from the global trend toward species specialization and monoculture intensification. China’s carp aquaculture has also pioneered a “productive conservation” approach where ecosystem services provision (e.g., water quality improvement through filter-feeding carps in lakes) [144,145] generates economic returns while delivering environmental benefits [146,147,148].

Third, the scale-integration dynamic reveals how massive production volumes [4] enabled both vertical integration opportunities [24,105] and horizontal coordination mechanisms [46] that smaller aquaculture sectors cannot achieve. The interplay between individual farmer decisions, cooperative structures, and state-level planning created feedback loops that amplified both successes and challenges across the entire value chain [43,44,45]. China’s experience reveals that domestic market development [13,99] can provide more stable foundations for aquaculture growth than export-oriented strategies. The focus on affordable protein provision for domestic consumption [93,94] created steady demand that supported sectoral expansion through multiple economic cycles, unlike export-dependent sectors that face greater volatility.

The convergence of sustainability pressures, technological capabilities, and changing consumer preferences is driving China’s carp aquaculture toward a “precision polyculture” model that combines traditional ecological principles [22,136,137] with advanced monitoring and management technologies [80,81]. This emerging paradigm offers potential pathways for other countries to achieve sustainable intensification without sacrificing ecological resilience.

However, the aging workforce and youth migration challenges [185] highlight the need for institutional innovations that make aquaculture attractive to younger generations. Solutions may require fundamental restructuring of labor arrangements, technology interfaces, and value distribution mechanisms within the sector [188].

The integration of carp aquaculture with broader circular economy initiatives represents an emerging opportunity where waste streams from other sectors become inputs for aquaculture systems [22,135], while aquaculture outputs serve multiple functions beyond food production [149,152,153]. This systems-level integration could provide a template for sustainable rural development strategies globally [155,156].

While this review employs a comprehensive sustainability framework encompassing environmental, social, and economic dimensions, future research would benefit from applying structured Environmental, Social, and Governance (ESG) indicators specifically to China’s carp aquaculture sector. An ESG-based assessment framework could enhance the sector’s integration with global sustainability standards and facilitate meaningful international comparisons.

7. Conclusions and Take-Away Messages

Although carp plays an important role in China’s freshwater aquaculture industry, it also faces a series of challenges. To improve farming benefits and ensure ecological safety, farmers need to take a series of measures such as optimizing farming techniques, reducing farming costs, improving farming efficiency, strengthening environmental protection facilities, etc. In addition, the government also needs to increase support for aquaculture and guide farmers in adopting advanced technology to promote the sustainable development of China’s aquaculture industry.

Key lessons include: (1) Aquaculture policies focused on long-term balanced sustainability across economic, social, and environmental realms rather than solely maximizing short-term yields or profits; (2) Smallholder capacity building through financial services access, cooperative formation, and technical skills training for precision agriculture adoption. (3) Vertical integration via contract farming models to strengthen resilience across supply chains; (4) Product and market diversification beyond commodity species to capitalize on consumer trends; (5) Proactive climate adaptation planning to leverage selective breeding and integrated systems.