The Spatial Ecology and Conservation of Seagrasses of the Gulf of Kachchh, Gujarat

Abstract

Seagrass ecosystems provide ecosystem services that rank among the highest in economic valuation worldwide. They also provide a range of economic, social, and environmental goods and services, which greatly increase coastal communities' resilience to the impacts of climate change. As unique marine habitats, seagrass ecosystems provide shelter and food for marine species during different life stages and contribute to sediment accretion and primary production. The high diversity of marine plant and animal life supports tourism activities and provides the raw materials for medicinal, agricultural, and structural applications. Furthermore, the physical structure of seagrass ecosystems attenuates wave height and speed, protecting coastlines from erosion and storm surges. Threats to seagrass ecosystems in the coastal areas of the Gulf of Kachchh include pollution, rising sea levels, eutrophication, reduction of light intensity and die-back. These all negatively impact seagrass ecosystems, such as increasing growth of epiphytes, sediment anoxia, or increased prevalence of diseases. Further, the effects of climate change on seagrass ecosystems will be additional stressors. The underlying factors affecting seagrass ecosystems are direct human pressures such as pollution, disturbances, and eutrophication. The combined stressors – human pressures and climate change impacts – are likely to exceed the thresholds for seagrasses, leading to, among other things, i) redistribution (reduction and coastal migration) of existing habitats and ii) widespread seagrass ecosystem die-off. In this context, this study was conducted between January 2018- March 2022 and aimed to understand the phenology, biomass and spatial distribution patterns of seagrasses of the GoK, using which I attempted to understand the foraging behaviour, habitat use and movement ecology of dugongs in the Gulf of Kachchh. The major objectives of the study include a) Mapping the distributional characteristics and patterns of seagrass meadows in the southwestern GoK, b) understanding the seasonal variations in the abundance of seagrasses on topographically distinct meadows, c) investigating fine-scale and topographical determinants of dugong habitat preferences and d) to assess the role of semi-diurnal tides' influence on dugong foraging habitats.