Remember the blue glow in Chennai beaches? Study finds it’s bad for fishes
Since the night of August 18, a blue glow was witnessed in a couple of beaches - Thiruvanmiyur and Elliot’s in and around the city - which also led to animated discussions over the social media.Updated: Aug 25, 2019 16:41 IST
Analysis of samples has established that a blue glow witnessed recently in and around the city’s coastline was due to blooming of sea sparkle species, a National Centre for Coastal Research (NCCR) scientist said on Sunday. After a blue glow, known as bioluminescence was witnessed here, samples were collected by the NCCR to establish various parameters and scientifically confirm the species behind it.
“We have confirmed that it is Noctiluca scintillans (sea sparkle) of dinoflagellate (unicellular organism),” an NCCR scientist told PTI. The species grew in size in a matter of few days and were also seen in places including Akkarai, Thiruvanmiyur and Elliot’s beaches, he said.
Tamil Nadu Dr J Jayalalitha Fisheries University Vice Chancellor S Felix had on August 20 said the blue glow may be due to the blooming of “non-toxic marine dinoflagellate species, called Noctiluca scintillans.” Generally, the formation of this bloom is considered a bad sign for decline of fisheries in the particular location, Felix added.
“Sometimes, the liberation of ammonia from the cells of the noctiluca may cause the large-scale mass kill of fish during the crash of the bloom,” he remarked.
Since the night of August 18, a blue glow was witnessed in a couple of beaches - Thiruvanmiyur and Elliot’s in and around the city - which also led to animated discussions over the social media. While some shared pictures, a few shared videos too:
The species, in view of its phosphorescent glow during night hours, is commonly called “sea sparkle,” according to the varsity head. The bioluminescent light emitted by this organism in the sea water will be blue during night and during day, the water will look greenish.
It is slimy in nature during heavy bloom since it has “endosymbiotic (organism that lives in the cells of another organism) green algae species Pedinomonas sp.” The blooming of bioluminescent marine algae generally appears after rainfall along the coast, which might bring in lot of nutrients and organic loadings and this could favour a sudden outburst in multiplication of this species, he said.
This species is known to feed on organisms including minute phytoplankton (consisting of microscopic plants), fish eggs and micro zooplankton (tiny organisms, which are protozoans and animals).
Both phytoplankton and zooplankton are tiny organisms that float over the sea and fresh waterbodies and play a key role in the marine ecosystem.
First Published: Aug 25, 2019 16:38 IST