The thermal discharge from coastal nuclear power plants and thermal power plants (CNATPP) not only increases the water temperature, but it also stratifies the seawater. Comprehending the characteristics of stratification that is caused by thermal discharge constitutes the basis for developing a comprehensive understanding of how thermal discharge affects marine organisms. The spatial and temporal characteristics of seawater stratification induced by thermal discharge were analyzed on the basis of measured data while using two study areas with different tidal dynamics as examples. The results showed the following. (1) Thermal discharge influenced the area within 3 km of the outlet. (2) In the East China Sea (which has strong tidal dynamics), the most significant stratification occurred 0.5 km–1.0 km from the outlet; however, in the South China Sea (which has weak tidal dynamics), the degree of stratification decreased with increasing distance from the outlet. (3) In the East China Sea (i.e., strong tidal dynamics), the depth of the thermocline during ebb tide gradually moved upward, while that during flood tide gradually moved downward, and the opposite was observed in the South China Sea (i.e., weak tidal dynamics). Finally, (4) the thermocline that was caused by thermal discharge mostly occurred at water depths above 7 m.

According to the 2017 results of the Special Inspector of Sea Reclamation, a substantial number of idle reclamation zones existed in 11 provinces (cities) along the coast of China. To improve the protection level of coastal wetlands and strictly control reclamation activities, it is necessary to carry out ecological restoration of reclamation projects and adjacent marine ecosystems. The characteristics of Guanghai Bay and its reclamation project are typical in China’s coastal areas, making it an optimal representative site for this study. The dissipative structure and entropy theory was used to analyze ecological problems and environmental threats. The analytic hierarchy process was applied to determine the order of the negative entropy flow importance. The entropy increase and decrease mechanism was used to determine an ecological protection and restoration scheme for the reclamation, including the reclamation of wetland resource restoration, shoreline landscape restoration, environmental pollution control, and marine biological resource restoration. Finally, based on system logic, a typical ecological restoration system was constructed east of Guanghai Bay, with the mangrove wetland area as the model in the north and the artificial sandbeach recreation area as the focus in the south.

Marine functional zoning (MFZ) is a type of marine spatial planning (MSP) implemented widely in China and one of the three major systems defined in the Law of the PRC on the Administration of Sea Area Use. China adopts “top-down management” for MFZ, in which upper management levels impose clear constraints and restrictions on lower levels. However, this approach has led to issues, such as a rigid MFZ classification system and unreasonable re-allocation of control indicators in the process of assigning MFZ classification at different levels. In this study, we propose and demonstrate the coordination of MFZ revision in terms of the classification system and the re-allocation of control indicators in the coastal city of Putian, China. The results show that the proposed measures could help realize the effective and reasonable coordination of MFZ revisions at the provincial and municipal levels, providing a reference for such MFZ revisions in other regions of China and the coordination of MSP between different levels in other countries.