In this study, we applied decoupling theory to explore the link between carbon emissions, sewage discharge, and fishery output growth in China from 2012 to 2021. The research results indicated that during the research period, the relationship between carbon emissions and fishery output was mainly weak decoupling, while the relationship between sewage discharge and fishery output was weak decoupling and expansive negative decoupling. Carbon emissions and sewage emissions were weak decoupling for most of the time. At the same time, the article defined the relationship between the environment and fishery production based on the decoupling state between the three, which are environmentally friendly, conventional, and polluting. It was discovered that China’s fishery production and environment still exhibit a polluting state. This means that there is a need for green and coordinated development of fisheries production and the environment, and corresponding measures must be taken. As a result, we have proposed policy recommendations that include optimizing aquaculture models, strengthening technological innovation and promotion of new technologies, and strengthening government supervision, management, and policy support.