Impacts of climate change on mariculture in coastal China: Spatial reconfiguration and structural adaptation

Abstract

As a pivotal component of marine fisheries, mariculture is confronting significant and multifaceted impacts from climate change. Understanding the climate change effects on fishermen's mariculture practices is crucial for safeguarding fishermen's livelihoods and ensuring global food security. Drawing upon panel data from 15 coastal cities in China during 2003–2022, we conducted a comprehensive analysis of mariculture spatial distribution patterns, subsequently developing a decision-making model for fishermen's mariculture to systematically assess climate change impacts. The study found that: (1) Climate change exacerbation will progressively diminish the marginal productivity of mariculture, depress fishermen's anticipated income levels, and consequently trigger a contraction in regional mariculture acreage. (2) The impacts of climate change show obvious species differences. Unfavorable climatic conditions, such as rising sea surface temperature and decreasing seawater pH, will further reduce the area of fish and shellfish mariculture, lowering the proportion of fish mariculture, thus inducing the fishermen to adjust their mariculture structure in order to avoid potential climate losses. (3) Additional analysis indicates significant heterogeneity in climate change vulnerability across production scales. The detrimental effects are more acute for large-scale mariculture enterprises in terms of area reduction, while rising sea temperatures markedly stimulate small-scale fishermen's transition toward shellfish mariculture. Therefore, it is necessary to enhance the climate early warning mechanism, tackle short-term climate changes, upgrade mariculture technology, optimize the structure of aquaculture species, increase policy support, and formulate differentiated subsidy strategies, so as to provide a reference for fishermen to adapt to climate change and stabilize their livelihoods.