Temperature effects on mariculture output in China: Evidence from causal forest analysis

Amidst global climate warming, investigating the impact of temperature variations on mariculture output is of critical importance for safeguarding national food security and advancing the high-quality development of marine fisheries. Drawing on panel data from 10 coastal provinces in China spanning 2010 to 2023, this study employs a causal forest model to analyze the causal effect of sea surface temperature (SST) rise on mariculture output, comprehensively controlling for covariates including capital, labor, technology, and marine environmental factors. The results indicate that rising SST exerts a significant negative impact on mariculture output. Mechanistically, temperature shocks exhibit nonlinear characteristics, with the marginal inhibitory effect on output varying as temperatures escalate. Heterogeneity analysis, conducted by evaluating the conditional average treatment effect (CATE) across diverse regional characteristics, reveals that the adverse impacts of temperature rise differ significantly under varying environmental conditions. Based on these findings, this paper proposes policy recommendations, including the construction of a differentiated, climate-adaptive fishery management system and the promotion of high-temperature-tolerant mariculture models.