Spatial Analysis and Prioritization of Environmental Pressures in the Anzali Wetland Watershed: A New Approach in Ecosystem-Based Management

Introduction: Due to their valuable and dynamic role, wetlands are often neglected in development policies and plans, which has led to rapid degradation and destruction. The Anzali International Wetland, which was once known as one of the richest and most beautiful wetlands on the southern shore of the Caspian Sea and even in the whole of Eurasia, is now on the verge of becoming a dry and lifeless marsh, as the average water depth has reached from 4.5 meters in the 1350s to less than 70 cm in 1404 and in many central areas of the lagoon, the depth has reached less than 30 cm. The research conducted on Anzali lagoon has paid less attention to a comprehensive evaluation of the root causes of the ecological and socio-economic threats to its destruction. Therefore, this issue underscores the need for a comprehensive study that identifies the root causes of degradation, with a focus on local anthropogenic factors. For this purpose, the aim of this research is to comprehensively identify the root causes of the destruction of the Anzali wetland, evaluate the performance of past management measures, and provide integrated, sustainable local management approaches for the long-term restoration and protection of this vital ecosystem.

Materials and methods: In the current research, in order to accurately identify the pressures and environmental threats on Anzali wetland, a combination of methods including a) conducting numerous field visits by the authors, b) collection of specialized information from experts of the General Department of Environmental Protection of Gilan province, and c) review and use of scientific articles, reports and published books related to Anzali wetland. Also, the data was organized in an integrated manner and the pressures and threats were listed for each of the rivers leading to the wetland separately and by type. Then, using aerial images and GPS location data, the threat points in the Anzali lagoon watershed were mapped in ArcGIS. In the following, the multi-criteria decision analysis (MCDA) method was used to prioritize the main threats related to the rivers entering the Anzali lagoon. The MCDA method used in this research was a simple weighted sum model.

Results: Based on the findings of this research, 56 main threats were recorded and observed in the rivers leading to Anzali Wetland, and for ease of prioritization, all of them were placed in 8 groups. According to the results, sedimentation and pollution had the highest scores, indicating that these factors can directly change the structure of the wetland. Moderate ratings included threats from invasive species and water abstraction/dam construction. Finally, the lower ranks included climate changes and Caspian regression, which, despite their high intensity, were ranked lower due to their low local (mainly global) controllability.

Discussion and Conclusion: This study provided a comprehensive picture of the environmental pressures on this valuable ecosystem using a mixed-methods approach. By identifying the pressures and threats on the Anzali wetland, he highlighted the need for a local approach to preserve it. The native model proposed in this research, inspired by successful global experiences and adapting them to the native conditions of Iran and the special characteristics of the Anzali wetland, is based on two main foundations, including: 1) Ecosystem-based management, which, unlike traditional management that often focuses on one factor, considers all degradation factors simultaneously and with a systemic view and 2) multi-level governance by establishing a single coordination council of Anzali wetland at the provincial level (with the presence of representatives of all relevant institutions, non-governmental organizations, local communities and experts) and its connection with the national and international (Ramsar Convention Secretariat) responsibilities will be clear and synergistic, in order to prevent the failure of scattered projects. This proposed indigenous model is fully consistent with the international frameworks of the Ramsar Convention and the Convention on Biological Diversity, as it emphasises the wise use of wetlands, the preservation of biodiversity, and the participation of local communities. The successful implementation of this model can be used as a local model for the management of other wetlands in Iran.