Enhancing the carbon emission efficiency of the fishery industry in the Yangtze River Economic Belt and fully leveraging its carbon reduction potential is of significant importance for achieving sustainable development in the fishery economy and the "dual carbon" goals, and the development of carbon emissions in the Yangtze River Economic Belt's fishery sector plays a crucial leading role nationwide. This paper, from the perspective of the "dual carbon" goals, utilizes social network analysis to thoroughly investigate the spatial network characteristics of carbon emission efficiency in the Yangtze River Economic Belt's fishery sector. Furthermore, it examines the carbon reduction potential in the Yangtze River Economic Belt's fishery sector from an equity perspective, integrating the analysis of fishery carbon emission efficiency. The following conclusion can be drawn. (1) The efficiency of carbon emissions in the fishery sector is characterized by imbalances, with network connectivity showing higher values in the east and lower in the west. (2) The network relationships are characterized by tightness, connectivity, and spatial spillover effects. Network density remains relatively stable, while network transitivity shows an upward trend. There is a high degree of collaboration between regions, and network efficiency still has room for improvement. The three Provinces of Jiangsu, Zhejiang, and Shanghai dominate the network, quickly establishing connections with other provinces, exerting strong control, and acting as nodes and intermediaries. Overall, carbon emission efficiency levels are excellent in the mid-to-lower reaches of the Yangtze River. (3) Beneficiary regions are concentrated in the lower reaches of the Yangtze River. Bidirectional spillover regions are mainly in the mid-to-lower reaches, broker regions are primarily in some cities in the middle reaches, and net spillover regions are concentrated in the mid-to-upper reaches. Shanghai and Jiangsu have the largest effective scale, the lowest degree of restriction, and the highest node independence, while Anhui and Jiangxi have the smallest effective scale.(4) Regarding the carbon reduction potential in the fishery sector of the Yangtze River Economic Belt, the potential in Jiangsu, Hubei, Chongqing, Shanghai, and Sichuan has been continuously declining, while Yunnan's potential has increased, and the potential in the other four provinces has remained relatively stable. (5) According to the Markov chain analysis of the carbon reduction potential in the fishery sector of the Yangtze River Economic Belt, the potential is relatively stable when the observation period t=1. As the observation period increases, the probabilities of low, medium-low, and medium-high levels of carbon reduction potential evolving to higher levels increase significantly.