VISAKHAPATNAM: Red-tinged waves were sighted along the RK Beach coast near the Kursura Submarine Museum on Monday night (December 15), prompting curiosity among denizens.
The occurrence was captured on camera by local Instagramer M Gnanesh, whose video later went viral on social media.
Explaining the phenomenon, Dr Ramesh Babu, Head of the Marine Living Resources Department at Andhra University, said the colour change might be linked to natural oceanographic processes involving internal currents and plankton activity.
“Just as the sea has surface waves driven by wind, it also has internal currents, including warm water currents that move along the coast from north to south. These currents transport microscopic plankton and, under certain conditions, cause them to accumulate near the shore,” he explained.
According to Dr Ramesh, when large concentrations of microplankton, including dinoflagellates and other algae, build up, they eventually break down.
“The organic debris and pigments released during this process are carried towards the coast by waves, giving the water a reddish appearance,” he said.
He noted that different algal groups dominate at different times of the year, depending largely on nutrient availability and temperature.
“There are various types of algae, such as blue-green algae, red algae and dinoflagellates. Their seasonal dominance is controlled by the presence of nutrients and temperatures,” he elaborated.
Nutrients, he added, are not naturally abundant in coastal waters, and are largely land-based. “During heavy rainfall, floods, river discharge, canal flows or sewage inflows, nutrient-rich water enters the sea. These nutrients are then redistributed by internal currents, creating favourable conditions for algal growth,” he noted, adding that the pigments present in these organisms determine the colour seen in the water.
Experts said the phenomenon could recur depending on nutrient levels, and prevailing ocean conditions. Since it is a natural process, it is not necessarily harmful on contact. However, they emphasised the need for responsible observation, and protection of coastal ecosystem.
Scientifically, such events are commonly referred to as algal blooms, sometimes described as red tides, which occur due to a rapid increase in algal populations.
Red tides are often caused by the proliferation of dinoflagellates, driven by factors such as warm surface temperatures, high nutrient availability and calm sea conditions.
However, experts cautioned that the exact cause and composition can be confirmed only after chemical and biological analysis of water samples.
However, experts lamented the declining interest among the younger generation in understanding their surroundings and current events. It may be recalled that bioluminescent waves were recorded for the first time at Bheemili Beach in April 2023.
The story is reported by Usha Peri of The New Indian Express