A first record of Halodule pinifolia Miki den Hartog, and new locality of nationally endangered Halophila beccarii Asch, from the eastern coast of Sri Lanka

This study presents the first record of Halodule pinifolia on the eastern coast of Sri Lanka, approximately 310 km along the coastline from the previously recorded location (Kapparathota, Weligama). Further, this study describes the new locality of the nationally endangered seagrass species Halophila beccarii to Valaichchenai Lagoon, 26.5 km north of Batticaloa Lagoon, where it was previously recorded, along with the presence of two other species, Halophila ovalis and Halodule uninervis. While the species composition the seagrass habitat of Valaichchenai Lagoon might change in the near future due to the impact of climate change, multiple threats already exist at these newly discovered seagrass habitats, including multiday fishing vessel movements, the collection of shells on the seagrass beds, and solid waste dumping into the lagoon. Decline of seagrass abundance in Valaichchenai Lagoon would negatively impact the food security and income generation of fishers. Therefore, a well-established legislative framework and systematic long-term monitoring of seagrass in Valaichchenai Lagoon are essential in order to develop seagrass conservation plans before populations decline significantly or become locally extinct.