The El Niño-Southern Oscillation (ENSO) is a consequential climate phenomenon affecting global extreme weather events often with largescale socioeconomic impacts. To what extent the impact affects the macroeconomy, how long the impact lasts, and how the impact may change in a warming climate are important questions for the field. Using a smooth nonlinear climate-economy model fitted with historical data, here we find a damaging impact from an El Niño which increases for a further three years after initial shock, amounting to multi-trillion US dollars in economic loss; we attribute a loss of US$2.1 T and US$3.9 T globally to the 1997-98 and 2015-16 extreme El Niño events, far greater than that based on tangible losses. We find impacts from La Niña are asymmetric and weaker, and estimate a gain of only US$0.06 T from the 1998-99 extreme La Niña event. Under climate change, economic loss grows exponentially with increased ENSO variability. Under a high-emission scenario, increased ENSO variability causes an additional median loss of US$33 T to the global economy at a 3% discount rate aggregated over the remainder of the 21st century. Thus, exacerbated economic damage from changing ENSO in a warming climate should be considered in assessments of mitigation strategies.

Deep-sea cage aquaculture (DSCA) is an important way to expand new space for marine aquaculture, promote the transformation and upgrade of the fishery industry, and optimize the structure of marine aquaculture. Using the panel data of DSCA in China’s coastal areas from 2013 to 2021, this study constructs the SBM–Malmquist model to measure the DSCA production efficiency and analyzes its total factor productivity. The results show that the overall DSCA production efficiency exhibited an increasing trend in spite of a sharp decline in 2019. The efficiency exhibited regional differences, being the strongest in the Bohai Sea region, followed by in the Yellow Sea, the South China Sea, and the East China Sea regions. The overall total factor productivity remained generally stable, although a large fluctuation occurred between 2019 and 2021. Both pure technological efficiency and scale efficiency promoted the total factor productivity in 2019–2021, while the efficiency of technological changes in societal aspects declined. This study shows that the DSCA production efficiency is significantly influenced by input factors such as labor and capital investment. In addition, natural disasters inhibit the improvement of the production efficiency to some extent.

This study establishes a three-party evolutionary game model that includes marine ranch firms, consumers, and the government, with a focus on the digital transformation pattern of marine ranching. Subsequently, the researchers conduct gaming and simulation to analyze the government subsidy strategy in the digital transformation of marine ranching. The following findings are derived: (1) Government subsidies have the potential to facilitate the digital transformation of marine ranches, benefiting both the supply and demand sides. Government subsidies positively influence both the digital transformation of marine ranch firms and the involvement of consumers in this transformation process. (2) The findings from the evolutionary game system demonstrate that alterations in the cost–benefit dynamics of each participant lead to adjustments in the steady state, thereby prompting the government to adapt its optimal subsidy strategy. (3) More government subsidies are not always better. Excessive government subsidies will destroy the stability of the evolutionary game system, which is not conducive to the realization of the digitization of marine ranch. (4) Subsidizing consumers is more effective in driving the digital transformation of marine ranch than subsidizing marine ranch firms. Subsidies to marine ranch firms will destroy the stability of the evolutionary game system, whereas subsidizing consumers contributes positively to its stability.

Bottom cold water mass provides abundant nutrients and cool water in summer, playing a pivotal role in the productivity of marine ecosystem and sustainable aquaculture development. Located in the most densely populated region, the Yellow Sea cold water mass (YSCWM) is a unique one influencing hundreds of millions of people living in the rim of the Yellow Sea. As anthropogenic carbon emissions continue, how the YSCWM will be altered by climate change becomes a pressing issue, but remains elusive. Using an unprecedented set of climate models with high resolution and biogeochemical components, we find that the volume of the YSCWM will shrink by 48% to 2040–2050, along with the bottom temperature warming of 0.4 ± 0.1 °C dec⁻¹ and the dissolved oxygen concentration declining of 0.09 ± 0.04 mg (L dec)⁻¹. The significant destruction of the YSCWM is driven by the strengthened Yellow Sea Warm Current (YSWC). The reduced land-sea thermal contrast is the cause of the circulation change, by weakening the East Asian winter monsoon. Due to the resultant profound habitat reduction for marine life, predicting the change of the YSCWM will have far-reaching influences on the future policy-making for sustainable development of offshore aquaculture.

Introduction: The expansion of fishery development from offshore to deep-sea areas has become essential for countries to address environmental constraints and ensure food security. This study aims to establish a cooperative development model for deep-blue fishery involving the government, fishery enterprises, and consumers.Methods: We constructed an evolutionary game and simulation model to analyze the government's deep-blue fishery subsidy strategy. The model considers the interactions between the government, fishery enterprises, and consumers, evaluating how different subsidy strategies influence the development of deep-blue fishery.Results: Our results demonstrate that government subsidies can stimulate the growth of deep-blue fishery from both the demand and supply sides. Specifically, the likelihood of government subsidies positively affects fishery enterprises' engagement in deep-blue fishery development and consumers' willingness to purchase deep-blue fishery products. The evolutionary game system reaches different steady states based on the cost-benefit changes for the government, fishery enterprises, and consumers, leading to various optimal subsidy strategies.Discussion: The findings indicate that the amount of government subsidy should be optimized rather than maximized, as excessive subsidies may not yield proportionate benefits. Additionally, subsidizing fishery enterprises proves to be more effective in promoting the development of deep-blue fishery compared to subsidizing consumers. These insights can guide policymakers in designing efficient subsidy strategies to foster sustainable deep-sea fishery development.