In vitro antibacterial, cytotoxicity and haemolytic activities and phytochemical analysis of seagrasses from the Gulf of Mannar, South India

► Seagrasses exhibited predominant activity against human pathogens. ► Cytotoxicity of seagrass extracts exhibited lesser toxicity. ► Halodule pinifolia recorded minimum haemolytic activity. ► Seagrasses could be effectively used in the food and pharmacological industry.