‘Sea sparkle’ has affected marine food chain: CMFRI

The bloom of Noctiluca Scintillans on Karnataka coast has displaced microscopic algae

November 28, 2020 02:39 am | Updated 10:33 am IST - MANGALURU

Cause for concern:  The Karnataka coast has been witnessing ‘sea sparkle’ for the past one month .

Cause for concern: The Karnataka coast has been witnessing ‘sea sparkle’ for the past one month .

The bloom of Noctiluca Scintillans , commonly known as “sea sparkle” that the Karnataka coast has been witnessing since about a month, has displaced microscopic algae called diatoms, which form the basis of the marine food chain. This has deprived food for the planktivorous fish, scientists from the Central Marine Fisheries Research Institute (CMFRI), Mangaluru, have said.

The bioluminescent Noctiluca Scintillans also brightened the sea water during night. CMFRI’s Principal Scientist and Mangaluru Centre Head Prathibha Rohit told The Hindu the toxic blooms of N. Scintillans were linked to massive fish and marine invertebrate kills. Though the species does not produce a toxin, it was found to accumulate toxic levels of ammonia, which is then excreted into the surrounding waters, possibly acting as the killing agent in blooms.

The ammonia makes N. Scintillans unpalatable for most creatures. Only jellyfish and salps were known to prey on it. N. Scintillans grazes on other micro-organisms such as larvae, fish eggs, and diatoms. But the unicellular phytoplankton that live inside it can photosynthesise, turning sunlight into energy. They help their host cell survive even when food was scarce. Thus, N. Scintillans acts as both a plant and an animal, Dr. Rohit said.

She said field studies by the CMFRI in the Arabian Sea off the Karnataka coast since a decade showed widespread blooms of the green dinoflagellate, N. Scintillans . Blooms were witnessed on September 8 this year while in September 2018 too such bioluminescence was witnessed along the Someshwara beach in Dakshina Kannada and Mattu in Udupi. This year, however, the intensity and vastness of the bloom close to the shore was observed by many.

Plankton bloom

Dr. Rohit said plankton bloom was reported when the density of plankton would be more than 1,00,000 cells per m3. Bioluminescence was the production and emission of light by a living organism and occurs due to a chemical reaction, involving a light-emitting molecule and an enzyme, called luciferin and luciferase.


Top News Today

Sign in to unlock member-only benefits!
  • Access 10 free stories every month
  • Save stories to read later
  • Access to comment on every story
  • Sign-up/manage your newsletter subscriptions with a single click
  • Get notified by email for early access to discounts & offers on our products
Sign in


Comments have to be in English, and in full sentences. They cannot be abusive or personal. Please abide by our community guidelines for posting your comments.

We have migrated to a new commenting platform. If you are already a registered user of The Hindu and logged in, you may continue to engage with our articles. If you do not have an account please register and login to post comments. Users can access their older comments by logging into their accounts on Vuukle.