1. Introduction
There is increasing demand for goods and services coming from coastal and marine areas due to limited or diminishing land resources. The utilization of marine resources is gradually expanding to deeper waters and farther offshore, such as aquaculture, offshore energy, shipping, and tourism [
1]. This makes coastal and marine areas more important to humans. In recent years, human beings have exploited ocean resources excessively, resulting in great damage to the ocean. For example, many coastal places or islands (e.g., Crete Island, Greece) are experiencing intense coastal erosion, large-scale tourism, and conflicts between land or sea users due to human expansion activities, so that the oceans of these coastal areas or islands are under enormous pressure [
2]. Furthermore, as the ocean becomes more industrialized, especially due to the significant growth in sectors such as aquaculture and renewable energy (e.g., offshore wind energy), potential conflicts between different ocean sectors are increasing over time [
3]. Most countries have designated or delineated some marine space for maritime transport, and the exploitation of human activities such as oil and gas, offshore renewable energy, offshore aquaculture and waste disposal. However, the development or use of these marine resources is usually dealt with individually by the relevant departments on a case-by-case basis. The impact on other human activities or the marine environment has not been comprehensively planned. Hence, this situation leads to two main types of conflict between human use, namely, user–user conflicts and user–environment conflicts [
3]. Addressing this situation requires cross-sectoral planning to optimize the use of marine space while facilitating the management of the various types of conflict that may arise [
4]. Therefore, to ensure the sustainable development of ocean resources, marine protected areas have been established worldwide [
5]. Using the method of zoning management, MSP has been developed to connect entire sea areas and coastlines [
6]. MSP is a relatively new planning approach, which aims at analyzing and organizing human activities in the sea space to achieve ecological, economic, and social objectives [
7]. The solution developed by MSP is a way that ensures equity and justice, so that all parties to the conflict can achieve a win-win outcome [
4].
Douvere [
1] reported that MSP is an adaptive decision-making method for dealing with latent conflicts among maritime transportation security, marine fishery, and the protection of important marine provinces. In the 1960s and early 1970s, Australia implemented a marine spatial planning program for the Great Barrier Reef Marine Park, to protect the Great Barrier Reef against massive limestone mining and oil exploration. The Intergovernmental Oceanographic Commission (IOC) of the United Nations Educational, Scientific and Cultural Organization (UNESCO) and the Man and the Biosphere Programme convened the first International Workshop in 2006. It indicated that the use of MSP is important for the implementation of ecosystem-based sea-use management and in setting up a marine strategic framework in consideration of balancing social, economic, and ecological goals. Stelzenmüller et al. [
8] stressed that MSP is not a one-time program but an adaptive management strategy in an ongoing process. With the implementation of MSP in many European coastal states, cross-city MSP or transboundary MSP has been taken more seriously [
9]. Therefore, MSP is one of the main tools for the holistic management of marine resources [
10]. MSP involves allocating marine space for different uses, considering the areas’ suitability, impacts on the environment and possible conflicts between activities [
11]. In addition, the maritime spatial plan covers all three dimensions of MSP (surface, water column and sea bed), and identifies areas for specific maritime activities, and it is a continuous process over time [
12]. Therefore, it can continuously and simultaneously solve problems such as sand and gravel extraction, offshore wind energy, marine aquaculture and marine fishing related to surface, water column, and the sea bed, and multidimensional problems in space and time. It can also solve the current situation of conflict between human development and the marine environment [
12]. Furthermore, MSP is dynamic and forward looking, rather than simply documenting the status quo. MSP should contain a temporal dimension, as the compatibility of specific marine uses and management needs may change over time [
13]. Based on this, MSP, as a means of dealing with declining ocean health, is a tool based on ecological protection, reflecting the ecosystem in an appropriate time and space. It is a mode and process of resolving human–environment conflicts [
13]. Moreover, humans are constantly moving into coastal and marine areas, and the information or data about the destruction of the ocean is changing at all times. Therefore, governing this issue requires more flexible management tools that can cope with this volatile marine environment. MSPs are, therefore, operating in an increasingly changing environment [
14].
The object of this study (the sea area between Kinmen and Xiamen) is suitable for the implementation of MSP. In the past decade or so, China’s land has developed rapidly. The large number of constructions has resulted in excessive river sand mining and has put infrastructure and buildings along the riverside at risk. Xiamen river sand is mainly from the influx of the Beixi and Xixi (two streams that merge to form the Jiulong River). However, the supply of river sand has been insufficient to meet the market demand. Suppliers began extracting sea sand from river outfalls and the sea area along the coastline of Xiamen [
15]. Without the consultation nor permission of the governments on both sides of the Taiwan Strait, ships began to mine sand in the waters of Kinmen that damaged the marine ecosystems of Kinmen and Xiamen and affected the safety of navigation. Moreover, it caused serious damage to the coastline of Kinmen, causing the influence of natural factors such as ocean currents, monsoons, and tides. The subsidence changed the coastal landscape.
The sea area between Kinmen and Xiamen (as shown in
Figure 1) off the southeast coast of China is surrounded by Xiamen, Zhangzhou, Quanzhou, and Kinmen. Residents in those four cities highly depend on the sea area for the co-use of marine resources. Stakeholders associated with this sea area comprise of fishermen, tourists who partake in water activities, transport operators, staff and passengers on liners, marine conservation teams, and law enforcement agents from Xiamen, Zhangzhou, and Quanzhou (China) and from Kinmen (Taiwan, China). However, without consultation or consent between the governments on both sides of the Taiwan Strait, the exploitation of sea sand by ships may have caused many long-term problems in the waters between Kinmen and Xiamen. It causes conflicts among stakeholders. Moreover, it has negatively impacted socio-economic diversity, including fishery production, collapse of the coastline, marine pollution, and the security of maritime entertainment (the cities surrounding the sea area between Kinmen and Xiamen include Kinmen, Xiamen, Zhangzhou, and Quanzhou. Kinmen and its sea area are under the jurisdiction of the Republic of China; therefore, Chinese citizens and ships are not entitled to enter or exit Kinmen’s territorial sea to engage in any fishery, industrial, or business activities without permission from R.O.C.). Fortunately, the implementation of MSP can support the socio-economic diversity of the sea area [
6].
Thus far, MSP has not been implemented in a cross-city or cross-border management mode for any sea areas adjacent to China and Taiwan. Although the sea area between Kinmen and Xiamen is jointly used by residents of Kinmen, Xiamen, Zhangzhou, and Quanzhou, it belongs to China and Taiwan. Since this sea area is surrounded by four cities, problems concerning it must be solved jointly by four municipal governments and their citizens, so that conflicts among all stakeholders can be minimized. Through data collection, analysis, in-depth interviews, and an expert opinion survey, this study was expected to build an ecosystem-based management mode, i.e., a mechanism for Kinmen, Xiamen, Zhangzhou, and Quanzhou to jointly manage the sea area between Kinmen and Xiamen. It provides practical strategies for MSP to sustainably use marine resources, and couple social, economic, and ecological effects together to mitigate conflicts among stakeholders and further achieve the goal of socio-economic diversity. It was believed that, by presenting this study, activities that are harmful to the sea area between Kinmen and Xiamen can be effectively managed and marine ecosystems and maritime security can be jointly maintained to protect the surrounding landscapes and landforms.
The objective of this study was to resolve conflicts among stakeholders associated with the sea area between Kinmen and Xiamen by the application of MSP and support their sustainable use of this sea area. In this way, the diverse use and value of this sea area can be achieved. Explicitly, this study was engaged with the following: (1) analysis of how ocean currents, monsoons, tides and sand mining destroy the coastline of Kinmen and the sea area between Kinmen and Xiamen, (2) analysis of how, without consultation or authorization from the governments of both sides of the Taiwan Strait, sand mining impacts maritime security in the sea area between Kinmen and Xiamen, (3) analysis of how laws are enforced in the sea area between Kinmen and Xiamen, and (4) the establishment of a sustainability mechanism for Kinmen, Xiamen, Zhangzhou, and Quanzhou to jointly manage the sea area between Kinmen and Xiamen.
4. Discussion
This study utilized a literature review, data collection, field study, and in-depth interviews with law enforcers in the sea area between Kinmen and Xiamen, stakeholders, Chinese and Taiwanese scholars. It found that:
4.1. Many Natural and Anthropic Factors Have Caused Kinmen’s Coastline Retreat and Landform Changes
The land of Kinmen is eroded and washed out in summer but silted up in winter, except the northern coast [
26]. Studies have indicated that the remaining eroded areas are mainly from long-term natural factors, such as ocean currents, tides and typhoons, and the anthropic factors of illegal sand mining and coastal development. Kinmen is a small island without high mountains or long rivers to bring abundant sand sources. Consequently, without collaboration to stop the disorganized development of the coast and illegal sand mining in the sea area between Kinmen and Xiamen, the coast of Kinmen would unceasingly retreat, and even the embankment could not protect the coastal landscape or prevent coastal retreat. The evidence is that the natural and anthropic factors have not only impacted the existential security of Kinmen citizens but have resulted in seawater intrusion, soil salinization, landform changes, coastal retreat, and erosion as well. For example, the coastline at Xintou of the Jinhu Township has collapsed and been eroded. It resulted in the bottom of bollard for navy landing boat’s supply operation being exposed and street lamp pole collapsing (see
Figure 6a,b).
4.2. The Difficulty in Law Enforcement in the Sea Area between Kinmen and Xiamen
The mutual legal assistance between Taiwan and China concerning subject hierarchy and differences in power allocation and in criminal evidence are the primary problems in the collaborative collection of evidence for criminal investigation. Evidence collection for criminal investigation belongs to different units. In Taiwan, prosecutors are the only investigation subject. In China, criminal investigation is subject to the authority of public security [
43]. If law enforcers want to ban illegal sand mining based on the mechanism of fighting crime collaboratively by Taiwan and China, the differences in collecting evidence for criminal investigation will still make it difficult to happen (Hsu, 2016). In another aspect, the sea area of Kinmen seems to be a haven for illegal-sand-mining ships. When a coastal-surveillance radar detects an illegal-sand-mining suspect in the sea area, and Kinmen’s patrol boat gets close to the specific area, the China-owned ship quickly returns to the sea area of Xiamen. This is what makes maritime law enforcement laborious. In addition, the legal consequences are not serious enough to deter unscrupulous people. When an illegal sand mining ship is seized by Taiwan, it is fined TWD 3 million, and the ship and staff are detained for two months. Apparently, this penalty has not deterred people from illegal sand mining. Constrained by cooperation from China, the frequency of cross-strait collaborative law enforcement is not high enough. From 2009 to 2016, the number of the collaborative enforcement cases was 20 in seven years, with an average of 3 to 4 each year, and a total of six vessels were seized. Considering environmental damages, impacts on navigational safety and economic interest, there is still wiggle room for enhancing penalty and collaborative-enforcement frequency. To solve the above problems, the Taiwanese government should make legitimate regulations on the issue of vessels’ illegal sand mining, enhance law-enforcement capacity, and strengthen the mechanism for cross-strait collaboration on crime fighting.
In summary, to prohibit the illegal sand mining by the sand-pump dredgers, Taiwan has amended the Article 36 of the Sand and Gravel Excavation Act. Sand and gravel excavation without permission using vessels or other machinery equipment in the internal waters and the territorial sea of the Republic of China, and restricted or prohibited waters in the Kinmen, and the Nansha Islands, shall be sentenced to imprisonment for not less than one year but not more than seven years; in addition thereto, a fine of not more than NTD 100,000,000 may be imposed. The vessels or other machinery equipment used in committing an offense set forth in the preceding paragraph that has been finally judged to be confiscated, may be auctioned, sold, disposed of, or preserved for public use in line with the circumstances of each case without any compensation. The aforementioned amendments may curb the current unscrupulous and illegal activities of the sand-pump dredgers. However, the only way solving the illegal-sand-mining issue in the Kinmen–Xiamen waters is to establish an MSP management mechanism for Kinmen, Xiamen, Zhangzhou, and Quanzhou, since it covers the transboundary marine law enforcement and overall ecological conservation of the sea area, and the governments, people, and all stakeholders of these four areas could participate together.
4.3. Overall Discussion of Research Results
4.3.1. Environment Protection of Sea Area
In summary, the long-term natural factors of ocean currents, tides and typhoons, the anthropic factors of illegal sand mining, and coastal development, have caused the loss of territory in Kinmen, damage tp the living environment, reducing the habitat of the lancelet, and the impact on the benthic environment would ultimately lead to the depletion of fishery resources. It shows that the Kinmen–Xiamen waters is facing a serious marine environmental protection crisis. This relies on the attention and collective wisdom of all parties to formulate a marine-environment protection policy and relevant specific practices to enhance the protection of marine resources. At present, in response to the regression of the coastline, the Kinmen County Government has put small gravel in black canvas bags with big boulders on top in order to prevent the continuous collapse of coastline soil, as shown in
Figure 7a,b. However, the effectiveness has not yet be verified. In addition to education of marine ecological conservation, short-term measures should include removing the nets and fishing equipment illegally deployed at sea by fishermen. The six major methods are driving away or detaining the ships; detaining personnel for investigation; confiscating ships, fishing equipment, and fish harvested; and administrative fines. Strong law enforcement should be implemented to fully protect the environmental resources and marine conservation of the Kinmen Waters. Moreover, in the short term, it should impose severe punishment on illegal-sand-pump dredgers. To achieve the effect of severe punishment on, and deterrence to, the sand=pump dredgers, additional fine may be imposed by the Coast Guard Administration in accordance with Article 80-1 of the Act Governing Relations between the People of the Taiwan Area and the Mainland Area. The sanction given to the Coast Guard Administration to auction, sell, dispose, or preserve the vessel for public use without compensation should also be evaluated. Moreover, it is expected that mainland China could jointly formulate “Cross-strait Natural Ecological Conservation Cooperation Agreement” as soon as possible, to effectively regulate and prevent illegal-sand-mining activities.
4.3.2. Maintaining Maritime Safety
The Kinmen–Xiamen waters is narrow and congested. Different channels, fishing boats activities and official ships for law enforcement have made the sea area almost saturated. If a sand-pump dredger broke into the Kinmen–Xiamen waters for illegal sand mining, it would pose a threat to maritime safety in that sea area. It is an existing and urgent issue of “Maintaining Maritime Safety” in the Kinmen–Xiamen waters. The solution does not only rely on the attention of the government and non-governmental organizations, but the cross-strait governments should also muster the courage to ban illegal sand-pump dredgers as well. On one hand, the Coast Guard Administration in Kinmen should increase the capabilities of law enforcement. On the other hand, the cross-strait governments should obtain consensus on law enforcement through communication and coordination. In terms of practice, the measures may include combining the radar to master real-time movement, on-site investigation, banning and bringing to justice, enhancing the patrol of the channels, and enhancing the marine services in Beiding, Liuluo Bay, Jinlie Waterway, Dadan and Erdan.
4.3.3. Cross-Strait Jointly Ban Illegal-Sea-Sand Mining Cooperation Mechanism
Taiwan and mainland China have signed the “Cross-Strait Joint Crime-Fighting and Judicial Mutual Assistance Agreement” to effectively combat the illegal-sand-mining activity. In May 2015, Taiwan spent a lot of efforts to promote the “Xia Zhang Meeting” between the chairman of the Strait Exchange Foundation and Association for Relations across the Taiwan Strait, and reached an agreement on the issue of illegal sand mining. According to Cross-Strait Joint Crime-Fighting Agreement, both sides have simultaneously banned and investigated the illegal activities and would continue to discuss the effective implementation of the solution. With the agreement, both sides had carried out 19 joint law-enforcement operations by the end of 2015, and seized 56 ships of illegal sand mining that damaged the marine environment. Right after Tsai, Ing-Wen was inaugurated as Taiwan’s 14th president on 20 May 2016, the joint law-enforcement mechanism in the Kinmen–Xiamen waters became less active than before. Although the cross-strait first line law-enforcement agencies still have the cooperation mechanism, the achievement is limited in the absence of a formal operation mechanism.
However, the council speaker of Kinmen County Council led a delegation visiting the Xiamen Ocean and Fisheries Bureau on 5 June 2018. It was to establish that a cross-strait joint law-enforcement mechanism in the Kinmen–Xiamen waters would be very important to the protection of marine organisms and the conservation of the marine resources and ecology of Kinmen Waters. Both parties also agreed that the law-enforcement unit of Xiamen Ocean and Fisheries Bureau and Kinmen Offshore Flotilla establish a rapid law enforcement cooperation mechanism to communicate and respond in real time to demonstrate the effectiveness of law enforcement, so that the resources in the Kinmen–Xiamen waters could be well protected [
18]. In addition, the Xiamen Municipal Ocean Development Bureau mentioned on 30 September 2018 that the maritime-patrol department in mainland China should “actively promote Xiamen-Kinmen coordinated law enforcement, complete and improve cooperation mechanism with the Kinmen coast guard unit, implement the normalization of coordinated law enforcement in Xiamen and Kinmen, exchange information in real time, jointly clean up the illegal fishing gear in the border waters, and jointly seize the illegal ships crossing the border” (Xiamen Ocean Development Bureau, 2018). Moreover, the Xiamen Ocean Comprehensive Administrative Law Enforcement Detachment carried out joint law enforcement with Kinmen, Zhangzhou, and Quanzhou on 20 August 2019, to maintain the order of fishery production in Xiamen Bay. During the operation, seven cross-strait vessels for law enforcement from the three regions carried out a coordinated law-enforcement cruise along the waters from Chijiao to Erdan Island [
44].
In summary, it is necessary for cross-strait governments from the four regions to carry out coordinated law enforcement in the Kinmen–Xiamen waters. Therefore, it is not only important but is necessary to establish the MSP marine management mechanism in Kinmen–Xiamen by Kinmen, Xiamen, Zhangzhou, and Quanzhou.
4.4. Establishing an MSP Marine Management Mechanism by Kinmen, Xiamen, Zhangzhou and Quanzhou
The establishment of a joint management mechanism for the sea area between Kinmen and Xiamen is the fundamental solution, i.e., a mechanism for the great Kinmen and Xiamen MSP. A Kinmen and Xiamen MSP, based on a cross-sector management approach, is a concept of marine management with an objective to break administrative boundaries and resolve problems incurred by fragmented governance through holistic marine management [
45]. Therefore, a Kinmen and Xiamen MSP requires the four main administrative bodies to cooperate with one another for the collaborative collection and analysis of spatial data regarding the sea area between Kinmen and Xiamen and for the proposal of framework management. Relevant stakeholders are encouraged to partake in the dialogues and negotiations. By clarifying opinions and relations with one another in the process of making an MSP, a management consensus may be achieved for joint marine management [
9].
Nevertheless, a Kinmen and Xiamen MSP still experience some challenges, such as the lack of a unified coordination and management mechanism. From an ecosystem perspective, the sea area between Kinmen and Xiamen is a complete marine ecosystem that needs integrated management. However, according to the current administrative boundary, the sea area between Kinmen and Xiamen is under the jurisdiction of four municipal governments, and is also involved with the different marine-management systems of Taiwan and China. The current differentiated management methods of administrative divisions have brought difficulty to the protection of marine ecosystems in the sea area. In the absence of the unified planning and protection of marine resources and with different governing rules and policy guidance for central or local legislation for marine jurisdictions, there must exist conflict management and loopholes in law enforcement. Hence, in the sea area, there has been long-standing illegal sand mining, blast fishing, and electrofishing. The sea area between Kinmen and Xiamen is experiencing an uncontrollable overuse of marine resources. There is also a lack of cross-sector cooperation on marine-environment-quality monitoring and marine-pollution prevention and control. Although the governments of Kinmen and Xiamen are aware of the importance of ecosystem management and joint management, they still act independently in matters of marine-environment-quality monitoring and marine-pollution prevention and control, without cross-sector cooperation. Conflicts in space and time among maritime activities make it difficult to strike a balance between development and protection. China once attempted to resolve the conflicts among various maritime activities through marine-functional zoning and achieved some results. However, subject to the administrative framework, there is still no overall arrangement for marine activities in the sea area between Kinmen and Xiamen [
9]. The economy of Kinmen currently relies on the benefits brought by the tourism industry. Its policy concerning environmental protection has always been clear, but there is not yet any marine-functional zoning or MSP to reduce conflicts between marine development and protection. Both governments are required to join forces to innovate a marine-managing mechanism and actively promote an ecosystem-based MSP to deal with existing problems and challenges in the sea area. If both Taiwan and China put aside political disputes and the immediate interests of the respective administrative regions and cooperate with each other on joint management, the healthy and harmonious development of the Kinmen and Xiamen waters can be realized.
Basically, a framework of MSP is needed to proceed with the establishment of a sustainable environmental plan between Kinmen and Xiamen to reduce the destruction of the marine environment and changes in the coastal landforms. Although there are many political issues between Taiwan and China, due to increasing conflicts among stakeholders in relation to this sea area, governments on both sides should ignore the political factors and utilize the MSP mechanism to resolve the conflicts that are less involved in politics. This is also a common expectation from the governments and people of Kinmen, Xiamen, Zhangzhou, and Quanzhou.
To conclude, this study has collected a lot of information from literature, which has revealed many discussions and data on the impact of the long-term natural factors and anthropic factors on collapse of Kinmen coastline, damage of marine ecology, and maritime safety. This study has been supplemented with field surveys, in-depth interviews, and expert opinion surveys, which have verified many findings of the existing literature. However, the Kinmen coastline and the current situation of sea area has been caused by multiple factors. It may not be completely attributable to any single factor, nor can it measure the ratio of the liability. This would be the limitation of this study.
5. Conclusions
In summary, the space to which the marine environment belongs is a complex social–ecological system. Whether people use this sea area or not, stakeholders will be affected by this social–ecological system. How to plan and properly use the marine environment is extremely important. Regarding the longstanding marine environmental issues and the collapse of the coastline in the Kinmen–Xiamen sea area, this study concluded, from a literature review, interviews, and a panel discussion, that thorough efforts of stakeholders from both Taiwan and China are needed. By using an MSP as a guiding tool to establish a management mechanism for the sea area between Kinmen and Xiamen, the above problems can be effectively solved.
During the study period, scholars, experts, and law-enforcement agents from Taiwan and China held a symposium on an MSP for Kinmen and Xiamen at the National Quemoy University. The consensus reached in the symposium can be used as an important reference for the future establishment of an MSP in the sea area between Kinmen and Xiamen by the governments of Kinmen, Xiamen, Zhangzhou, and Quanzhou. In the symposium, it was suggested that (1) Taiwan and China should establish a “Cross-Border Cooperation Management Platform for the sea area between Kinmen and Xiamen” with scientific research organizations from both sides as the basis; (2) the implementation of a Kinmen and Xiamen MSP may encounter complicated difficulties. Both sides can start with current hot issues of illegal sand mining in this sea area and gradually proceed with research and development in related fields; (3) the competent organizations in Kinmen, such as the Fisheries Research Institute of Kinmen County and coast guard, should actively provide data and necessary scientific research assistance for the establishment of the Kinmen and Xiamen MSP; (4) Kinmen and Xiamen MSPs are necessary to create a data-sharing mechanism, such as cloud sharing or an online database; (5) in the future, a cross-strait Kinmen and Xiamen MSP implementation-leading group must be built to combine scientific research and the administrative forces of both sides to make plans in future. The previous suggestions can also be used as a reference for the governance of countries surrounding similar sea areas, such as the marine pollution problems of countries surrounding the Baltic Sea and the Mediterranean Sea.
Recommendations for Putting MSP into Practice
According to the findings of this study, an MSP could be applied to the cross-strait joint transboundary-marine-governance mechanism. It is necessary for an MSP to include all stakeholders in the planning system, i.e., through public participation, public opinion should be solicited and public support won over. The specific recommendations are as follows:
Firstly, the two sides of the strait should establish a cooperative management platform. An implementation-leading group should be formed and cross-strait discussion meetings should be held. For example, the two sides of the strait should establish a “Kinmen-Xiamen Waters Cooperation Management Platform” based on the scientific research organizations of both sides. Furthermore, the implementation of an MSP in the Kinmen–Xiamen waters may face many difficulties. Therefore, this could start from the hot issues faced in this sea area to monitor and informatize the location and time intervals of ocean currents, monsoons, tides, coastal development, and other anthropic factors such as unau-thorized sand mining. Thereafter, the research and development of related fields should be gradually promoted, and the problems of illegal sand mining would be solved, finally.
Second, is about the schedule and approach of MSP implementation. The construction of an MSP in the Kinmen–Xiamen waters is a creative interaction process involving the government and research institutions. Cross-strait academic circles could make use of informal exploration and consultations, such as perspective sharing in seminars, discussions or scientific-research cooperation in symposiums, or providing recommendations on cross-strait joint transboundary marine governance in the form of research results and reports. The schedule and approach are shown in
Figure 8, and are described as follows:
In the early stage of promotion, cross-strait academic circles could sort out and analyze the MSP theory and famous cases in order to provide empirical guidance and theoretical reference for the construction of an MSP in the Kinmen–Xiamen waters. Thus, in the primary stage of MSP construction, the local governments on both sides of the strait could explore the emerging public-management theories, such as global environment governance, cross-domain governance, and EBM, to reach the common consensus of an MSP. The proposal and development of EBM theory has provided effective theoretical guidance and practical value for the governance of transboundary marine environmental issues. In addition, in order to be successful, famous MSP practical cases should be analyzed. For example, the “Elkhorn Slough Tidal Wetland Project” included a national coordination and leadership mechanism in the policies and plans. If the theories and cases mentioned above could be considered when MSP is put into practice, it would be beneficial to integrate the actual situations of the Kinmen–Xiamen waters for comparative analysis, and provide practical guidelines for the construction of an MSP.
In the mid-stage of construction, the cross-strait academic circles could compare and analyze the different stakeholder, law, and technologies structures of both sides of the strait, determine areas of common interests, and provide policy references for government agencies. For example, in terms of stakeholders, it is required to define stakeholders first, followed by clearly regulating their participation methods, time and role, and understanding public opinions to avoid conflicts of interest. In terms of legal structures, the similarities, and differences, in the jurisdiction of the Kinmen–Xiamen waters could be compared. In terms of technical structure, it could be started from the establishment of a spatial database of the Kinmen–Xiamen waters to facilitate analysis of the geographic information system (GIS). In particular, the issue of cross-strait cooperation to combat the destruction of the marine environment involves the application of laws and the legal basis of enforcement methods. It is necessary to integrate the legal systems of both sides of the strait before conducting a transboundary MSP. Analysis of technology structures could help the establishment and sharing of cross-strait spatial database information. Obtaining high-quality and continuously updated ocean data would be critical for decision makers. Although there may be certain difficulties in the process, such as the matching of different administrative management systems and processes, and the accessibility and consistency of data and effective communication methods, local governments must constantly maintain the interests of their jurisdictions while seeking for cooperation in the areas of common interests [
46] in order to overcome the existing issues of transboundary marine governance.
In the latter stage of construction, the cross-strait academic circle should make a preliminary assessment of the Kinmen–Xiamen waters MSP, and adjust accordingly. It is necessary to conduct environmental-impact assessments for the transboundary spatial planning of the Kinmen–Xiamen waters. After the implementation, the possible impact on the Kinmen–Xiamen waters should be identified, predicted, and systematically evaluated. Efforts should be made to promote the sharing of interests and risks between the governments of both sides of the strait, and provide scientific guidance and policy planning for the governments of both sides of the strait in transboundary marine governance.
The three stages of constructing a Kinmen–Xiamen MSP are closely linked. We could say that the cross-strait academic circle would be the first step of the entire process of constructing a transboundary MSP in the Kinmen–Xiamen waters. In the preparation process, the cross-strait academic circle should solve several critical issues, including the way of promoting communication and exchange between cross-strait governments, the way to comprehensively consider the needs of stakeholders and organize public participation, define the required data, and establish a common information system. These three fundamental issues affect the entire process of constructing a Kinmen–Xiamen MSP [
9] (pp. 12–16). Especially, the destruction of the marine environment involves multiple aspects of law enforcement, marine conservation, and maritime security. The governments and people on both sides of the Taiwan Strait can only take care of the balance between marine ecology and human life through careful planning and communication in the three stages through an MSP.
In summary, to effectively remediate the environment of Kinmen–Xiamen water and the collapse of the Kinmen coastline, it is the top priority to establish a transboundary marine governance mechanism based on an MSP and public awareness of environmental protection. Unfortunately, this would involve the central governments of mainland China and Taiwan, and transboundary governance between local governments. With the development of marine ecological civilization worldwide, the topics of transboundary marine governance have begun to catch the attention of academia and government departments. As transboundary waters under the joint jurisdiction of Kinmen (Taiwan) and Xiamen (mainland China), the Kinmen–Xiamen waters are under the independent jurisdiction of two governments due to the two political entities. This has triggered illegal activities across the boundary in Kinmen Waters, such as smuggling and illegal immigration, floating marine debris, marine pollution, and illegal sand mining. The traditional administrative boundary governance can no longer solve the complex problems in transboundary waters. The governance effectiveness and efficiency are worrying. Although both Kinmen and Xiamen have extensive cooperation in the Kinmen–Xiamen waters, such as “channeling water to Kinmen”, “cross-border fishing”, “illegal sea sand mining” and “jointly releasing fries to the sea”, it is restricted to the cooperation between the local governments of Kinmen and Xiamen, and is full of uncertainty due to the political factors [
47]. Therefore, at the management level, it is necessary for the governments on both sides of the strait to establish an MSP-based transboundary marine governance mechanism in the Kinmen and Xiamen waters.