Environmental Stress Response of Tropical Seaweeds Physiological and Metabolic Processes

Abstract

The global climate change crisis has increased the interest in studying how different environmental stressors affect seaweeds. The seaweeds are foundation of the coastal and marine food web and play a vital role in the sustainability of the marine ecosystem. They also have many nutritional and environmental advantages. However, seaweeds face various environmental stresses such as high temperature, desiccation, salinity fluctuation, varying light intensity, pH variation etc. These stresses can affect their photo-physiological performance and biochemical compositions. These properties can vary depending on the seasonal and diel changes in biotic and abiotic factors. Tamil Nadu is the southernmost state of India and has a long coastline along the Bay of Bengal, the Arabian Sea and the Indian Ocean. It has a rich diversity of seaweeds with about 302 species out of the total 650 species found in India. Seaweeds are important for both ecological and economic reasons. They provide food and shelter for many marine organisms and also have nutritional and environmental benefits. Seaweeds can adapt to changing ecological conditions by altering their photo-physiological performance and biochemical compositions. During my PhD research, I investigated how some common tropical algae from two regions in Tamil Nadu - Palk Bay and Covelong - cope with seasonal and diel variations newlinexi newlineof these stressors, as well as with ocean acidification. I also explored the ecological and economic implications of these seaweed responses for coastal communities and marine biodiversity. newlineIn the first section of the study, we investigated how seasonality affects the biochemical and nutritional properties of the intertidal green seaweed Chaetomorpha antennina from the rocky shore of Covelong, India, in different seasons (from June 2019 to March 2020). These environmental changes may affect the nutrient uptake of the seaweeds. Seasonality had no effect on the photosynthetic parameters including pigments and primary productivity.