In this article we use carbon credits as the basis for regional sustainable developing policy-making, present the carbon cycle model of Gouqi Island, a typical coastal wetlands zone that locates in the East China Sea, to illustrate the relationship between human activities and natural environment in costal wetland through carbon credits, discuss the regional developing models and paths for Gouqi Island to achieve sustainable development, which can also be generalized to the sustainable development strategy of coastal wetlands zones.
According to the developing strategy of Gouqi Island, tourism has been regarded as one of the major industries in future, together with agriculture (mainly relies on mussel).
Gouqi Island locates in 30[degrees]43'1"N and 122[degrees]46'3 E where it is in the northeast among Zhoushan Archipelago, it is part of East China Sea coast and Islands wetland ecological system, the map of Gouqi Island is displayed in Figure 1, and the detailed information is listed in Table 1 .
The major industries in Gouqi Island are marine fishing industry and marine aquaculture, the marine fishing industries are developed in the area around the island and distant ocean, and the fishing industries are mainly developed along the coast, among which mussel culturing industry contributes around 95% to the industry considering both quantity and economic income.
 we develop a carbon cycling model based on the socioecological system with STELLA[R] software; the data used in the STELLA model mainly come from the following: (1) basic information of Gouqi Island from statistics reports; (2) data collecting from the tourists on the island with a questionnaire; (3), coefficients or parameters of processes in the model are cited from literatures; (4) field survey.
We develop a carbon cycle model of Gouqi Island based on the socioecological process that determines the emission of C[O.sub.2] through human activity and economic development and removals of C[O.sub.2] through natural environment process.
, 24 processes of carbon release and capture ways in social and natural systems of Gouqi Island were described by the development of the conceptual model.
Published information is cited from literatures that illustrate similar process or objective, and basic information related to Gouqi Island is cited from the statistic reports.
Table 6 shows the general result of the carbon cycle process of Gouqi Island in 2014, Figure 4 indicates the island has achieved a positive removal of C[O.sub.2] at the amount of 155401.
The island of Gouqi is named after a kind of major bush Chinese wolfberries Lycium chinense (in Chinese it is called Gouqi), which covers 53% percent of the mainland on the island.