A preliminary study on the environmental factors triggering frequent bloom of diatom Asterionellopsis glacialis (Castracane) Round 1990 along west coast of Bay of Bengal

Abstract

A time-series observation of Asterionellopsis glacialis (Castracane) Round 1990 bloom in the surf zone of east coast of India and associated physico-chemical parameters, was carried out during pre-monsoon period (May 2018). This study also reviews the species status as a surf-zone diatom and its temporal characteristics. Referring to the earlier study, the temporal characteristic of A. glacialis bloom in Indian context can be classified as "sporadic" due to the alteration of blooming community and may be also further investigated for its seasonality as the bloom mostly observed during the pre-monsoon season. Among the nutrients, silicate is identified as a major factor controlling the bloom of A. glacialis. The present study highlights the introduction of biogenic silica attributed to precipitation induced land runoff and the effect of wind as important environmental factors responsible for A. glacialis proliferation in nearshore waters of east coast of India.