Exploring resource and environmental carrying capacity and suitability for use in marine spatial planning: A case study of Wenzhou, China

The sea is the key to conducting sustainable scientific research and achieving strategic development of economic and environmental goals. The international community attaches great importance to the coordinated development of marine ecology, environment and socio-economic growth, and Europe has taken the lead in conducting relevant research. In recent years, although China has gradually tried to use quantitative and precise models for spatial planning, it still lacks a scientific logic - from theory to methodology - to address marine spatial planning. Based on the previous study of ecological and environmental quality and socio-economic development, this paper advocates the application logic of marine resources and ecological carrying capacity (MRECC) and marine use suitability (MUS). The Wenzhou City in Zhejiang Province was selected as the research area and MRECC is measured by four dimensions: spatial development of the marine area, fishery resources, environment and ecology. Two types of typical marine use, fishing use and construction use, were selected as the suitability for analysis to determine the optimal spatial arrangement of the sea and to assess the spatial conflict of the sea in Wenzhou. The results show that: (1) the comprehensive carrying capacity index of the marine area varies greatly among the districts and counties of Wenzhou city, and the resources and environment are highly differentiated. Longwan and Dongtou counties are overburdened with fishery resource development; Yueqing city and Longwan county are overburdened with marine environment. (2) There are only a few suitable areas for fisheries, and these are distributed in the nearshore area. The unsuitable areas are concentrated in the Oujiang River, Feiyun River and Aojiang River estuary. The areas that are particularly suitable for marine construction are concentrated in the coastal waters. The water depth in the near-shore area is far from urban settlements, which is not suitable for marine construction and development. (3) The spatial conflict phenomena in Cangnan County and Pingyang County are less - the spatial arrangement of marine planning is more reasonable. Yueqing City, Longwan County and Dongtou County have significant conflicts in the arrangement of marine fishery use and need to be optimised. Overall, the intensive development of the sea affects the carrying capacity and suitability of the sea, and inevitably leads to conflicts in the sea. Marine protection and development urgently require active management measures and sound spatial planning. The implementation of targeted and marine spatial planning with "double assessment" is of great importance for coastal spatial planning and an important means to achieve sustainable development of the marine economy. Therefore, the recommendations are to implement environmental protection of coastal areas, improve the level of marine development and balance the development of marine areas to promote the sustainable development of the region.