China’s Seafood Imports Are Nearing Their Ceiling, Study Finds

China’s appetite for imported fish, shrimp, mollusks, and edible algae has grown at a staggering pace over the past decade, transforming the country into the anchor customer of the global seafood trade. But a new analysis suggests that the remarkable boom is no longer driven mainly by unlocking new trade capacity. Instead, the story of the last ten years is one of steadily closing the gap between what China’s supplier relationships could theoretically deliver and what they actually deliver, with logistics competence on the Chinese side and free-trade-agreement experience on the supplier side emerging as the decisive factors.

The study, published in Frontiers in Sustainable Food Systems by Wei Yang and Kunlin Tang of Shanghai Ocean University, tackles a question that has puzzled trade economists: how much of the trade between China and its major seafood suppliers is actually being realized, and where does the unrealized potential remain? The researchers compiled a balanced panel of China’s sixteen largest aquatic-product suppliers, including Norway, Ecuador, Russia, Vietnam, the United States, and Japan, covering every year from 2013 to 2022. Together these sixteen countries account for roughly three-quarters to more than four-fifths of China’s food-use aquatic-product imports in any given year, making them the core of the import network.

Methodologically, the paper deploys a relatively sophisticated econometric tool: a true random-effects stochastic frontier gravity model. In plain terms, a gravity model predicts bilateral trade from economic size and distance, while a stochastic frontier analysis estimates the maximum attainable level of that trade given observable conditions, treating shortfalls as a distinct one-sided inefficiency rather than ordinary statistical noise. The true random-effects structure, introduced by economist William Greene, adds a crucial refinement by separating persistent differences between suppliers, such as geography or product specialization, from time-varying inefficiency that can improve or deteriorate year by year. This separation matters because a supplier that consistently ships less than its frontier might simply be a small, distant economy rather than an underperforming trade partner.

The results split neatly into two margins. On the capacity side, the size of China’s fishery-sector economy and each supplier’s total aquatic-animal production, combining capture fisheries and aquaculture, determine how large the conditional import frontier is. A frontier elasticity of 0.872 for China’s fishery output value implies that a ten percent expansion of the domestic aquatic-product economy supports roughly an 8.7 percent larger import frontier, while supplier production carries an elasticity of 0.384. Distance and the annual Dubai crude oil price enter separately, capturing persistent spatial separation and the common shipping-cost environment, respectively.

On the realization side, two institutional variables dominate. China’s logistics-service competence score, drawn from the World Bank’s Logistics Performance Index, carries a strongly negative coefficient of -4.655 in the inefficiency equation, meaning that better port handling, inspection, refrigerated transfer, and domestic distribution are associated with substantially lower trade inefficiency. Equally striking, the breadth of each supplier’s free-trade-agreement network with economies other than China also reduces inefficiency, with a coefficient of -1.382. The authors interpret this as evidence that repeated exposure to trade rules, origin documentation, certification procedures, and customs coordination across multiple partner markets builds administrative routines that travel with exporters, making them more effective even in their Chinese trade.

The robustness testing is unusually thorough for this literature. The FTA-network relationship survives the addition of a linear time trend, exchange-rate and fish-price controls, a COVID-19 indicator, deflation to real import values, alternative annualization of the logistics index, supplier GDP per capita, trade openness, World Bank Regulatory Quality scores, and a switch to a half-normal inefficiency distribution. Broader gravity samples of 78 and 98 suppliers estimated with PPML, a technique robust to heteroskedasticity, confirm the positive relationship between network breadth and realized imports. The authors even confront endogeneity directly, using Hausman-Taylor and Amemiya-MaCurdy panel instrumental-variable estimators and testing whether future leads of FTA breadth predict current imports; the temporal ordering supports the interpretation that accumulated agreement experience precedes stronger trade realization.

The headline numbers are dramatic. Average trade efficiency, estimated using the JLMS conditional estimator, rises from 58.00 percent in 2013 to 89.21 percent in 2022, with the value-weighted realization rate reaching 89.16 percent. In other words, a decade ago Chinese buyers captured barely more than half of the trade their supplier relationships could support; by 2022 they captured nearly nine-tenths. The aggregate conditional gap, the dollar difference between frontier and observed trade, shrank from roughly USD 5.43 billion to USD 2.24 billion over the period, and its share of the frontier fell from 43.55 percent to just 10.84 percent.

Where the remaining gap sits is just as revealing as its size. In 2022, observed imports of USD 18.41 billion from the sixteen suppliers corresponded to a conditional frontier of about USD 20.65 billion. The largest absolute shortfalls belong to Ecuador at USD 0.649 billion, Russia at USD 0.226 billion, and the United States at USD 0.222 billion, yet their efficiency rankings differ sharply. Norway, Vietnam, and Chile post the highest efficiency scores, above 93 percent, while an efficiency-frontier matrix classifies suppliers into four groups: core high-realization partners such as Vietnam and Russia, large-frontier relationships with room to grow such as Ecuador and the United States, efficient smaller suppliers like Norway that add specialization, and smaller relationships offering diversification options.

The findings carry practical weight for food security and supply-chain resilience. Aquatic products are perishable and cold-chain dependent, so border delays and logistics failures destroy value in ways tariffs do not. The authors argue that institutional opening-up, the alignment of formal trade rules with actual implementation on both sides of the transaction, is now the binding constraint on further realization. For a country sourcing roughly USD 24 billion of food-use aquatic products annually, the difference between an 85 percent and a 95 percent realization rate is worth billions of dollars, concentrated in a handful of large relationships rather than scattered across the network.

More broadly, the study offers a template for thinking about trade potential in any perishable food sector. Capacity formation and capacity realization are shown to be complementary dimensions: building bigger ports and signing more agreements expands what is possible, while procedural competence, digital certification, and customs cooperation determine how much of that possibility becomes actual trade. As global demand for blue foods continues to rise and climate pressures reshape capture fisheries and aquaculture, the efficiency with which established trade links convert capacity into deliveries may prove just as important as the expansion of new links, particularly for import-dependent nations trying to secure protein supplies in an increasingly volatile world.

Subject of Research: Trade efficiency and unrealized import potential in China's aquatic-product trade with major suppliers

Article Title: Institutional capacity, FTA network breadth, and trade efficiency in China’s aquatic-product imports: evidence from a true random-effects stochastic frontier gravity model

Article References: Yang, W., & Tang, K. (2026). Institutional capacity, FTA network breadth, and trade efficiency in China’s aquatic-product imports: evidence from a true random-effects stochastic frontier gravity model. Frontiers in Sustainable Food Systems, 10, Article 1963840. https://doi.org/10.3389/fsufs.2026.1963840

Image Credits: AI Generated

DOI: 10.3389/fsufs.2026.1963840

Keywords: China, aquatic products, seafood trade, stochastic frontier analysis, gravity model, trade efficiency, free trade agreements, logistics performance, trade facilitation, supply chain resilience, aquaculture, cold chain