Ecosystem-based approaches to develop a monitoring framework for restoring the transitional lagoon ecosystem of Pulicat, India

Monitoring habitat fragmentation (HF) for economically significant species at close-ranges can provide crucial data for deriving the indicators of the Sustainable Development Goals (SDG) 14.4 for complex socio-ecological systems such as coastal lagoons. However, exclusivity of local-scale processes causing fragmentation, differences in the monitoring approaches, differential interpretations of resilience to disasters, as well as mismatches in reporting outcomes of scientific studies indicate the need for a focussed monitoring framework for transitional ecosystems. Using the example of penaeid prawns (Peneaus sp.), an economically important species from Pulicat lagoon, (an intertidal ecosystem on the east coast of India), the present work presents the development of a practical framework using selective but effective indicators of HF. The overall approach involves establishment of baselines, causal loops, triggering transformations as well as adaptive responses as per the scale and magnitude of HF. In the context of deriving baselines (Level 1), in-situ indicators such as salinity, turbidity, chlorophyll-a concentrations and distribution of seagrass which directly influence the habitat selection are proposed. Derived datasets on nutrient budgets, changes in abundances, Representative Concentration Pathways scenarios 4.5 and 8.5 for climate-induced changes are proposed as external forcings to understand the causative parameters (Level 2). Monitoring extents of tidal influence in ecosystem-based approach for disaster risk reduction (EcoDRR) is proposed to evaluate triggers and adaptive responses (Level 3). The EcoDRR based framework presented has the potential to contribute towards policy-targeted transformative approaches relevant to India's National Fisheries Policy 2020 as well as SDG 14, cross-correlated with targets of other SDGs. [Display omitted] •New ecosystem-based modelling framework for transitional coastal lagoon ecosystems•Methodologies to assess evidence and extent of fragmentation at species-level•Eco-DRR and Red List of Ecosystems framework for upscaling to ecosystem-level•Example of Pulicat lagoon ecosystem, South-east coast of India