Impact of Sea Level Rise on Mangrove Ecosystem and its Dependent Fishing Communities in the Coastal Regions of Cauvery Delta: A Message for Policy Planners to Frame Suitable Antcipatory Adaptation Strategies

Coastal adaptation to sea-level rise (SLR) in the deltaic region is a multidimensional and complex process requiring informed decisions based on predicted impact and vulnerability assessment of SLR. Elevation plays a key role in determining the impact and vulnerability of coastal land areas to inundation from SLR. Highly accurate mapping of the elevation of the landscape is essential to identify low-lying coastal deltaic regions with valuable ecosystem like mangroves and its dependent human communities that are potentially at risk of inundation. It is difficult for policy planners and decision makers to identify suitable adaptation strategies without having information on the predicted impact and degree of vulnerability of coastal systems to SLR. Importantly, modeling and mapping will provide valuable input to climate change adaptation planning (NOAA 2010). Unfortunately, the comprehensive range of information that is typically required is seldom available and rarely in the possession of decision makers responsible for management of the deltaic and coastal zone (O’Regan, 1996).

The present study seeks to provide insights on predicted impact of climate change induced SLR on mangrove ecosystem and its dependent human communities of Pichavaram mangroves, located at the Vellar-Coleroon estuarine region on the banks of Cauvery delta, Tamil Nadu, India. Based on real-time on-ground elevation measurement by DGPS (Differential Global Positioning System) survey and by using GIS portals, the study has identified about 597 ha of mangroves (one third of total mangrove regions) and about 9 fishing hamlets with 12,000 and more of human population that directly depends on this mangrove ecosystem for their livelihood are under threat of inundation to the predicted impact of 0.5m SLR. The present study is intended to showcase a method by providing reliable scientific information on predicted impact of SLR on mangroves and its dependent human communities to policy planner for informed decision making. Very importantly, this study has made an attempt to develop a robust picture of ecosystem based and community centered anticipatory adaptation strategies to the risk of rising sea level that are grounded in pressing community priorities of coastal regions of Cauvery delta.