Mass mortality of regular sea urchin Salmacis virgulata L. Agassiz and Desor, 1846 at Dhanushkodi, Southeast coast of Tamil Nadu, Gulf of Mannar, India

Abstract

Mass mortality of sea urchin, Salmacis virgulata scattered over the periphery of Dhanushkodi beach, was observed on February 13, 2019. More than 100 numbers of recently dead and dying specimens were found within a 10 m² area on the sandy beach. Beach profiles indicated several hundreds of exoskeletons of previously dead S. virgulata were washed ashore and buried in sand and withering seagrass. The causative agent responsible for mass mortality of S. virgulata is yet to be discovered. However, observations on wave approach toward shore indicated possible evidence that it could be due to a combination of strong nearshore waves and currents. This observation raises a critical research concern to investigate etiology of S. virgulata for species conservation.