Truth behind sparkling beaches of the world
The Noctiluca algae, commonly known as
sea tinkle is a parasite and occurs in patches or ‘blooms’ in the Northern
Arabian Sea.
Many of us become fascinated after watching images or videos
of ocean water sparkling at night. Beaches found mostly in the tropical or
subtropical zone around the world is witnessing these symptoms. They attract a
lot of tourists to visit there for sightseeing and enjoyment. they are located
in Mexico, San Diego, Vietnam, India, The Maldives etc.
But are they really good for our marine ecosystem?
The phenomenon of Mumbai’s beaches glowing in the dark may
be a consequence of global warming and not industrial pollution, according to a year-long investigation by Indian and American scientists.
The Noctiluca algae, commonly known as sea tinkle, is a parasite
and occurs in patches or ‘blooms’ in the Northern Arabian Sea. They glow at
night due to bioluminescence, and have earned them the nickname ‘sea sparkle’.
However, these patches are a sign of decline because they
compete with fish for food and choke their supply. Noctiluca devours one of the
most important planktonic organisms at the base of the fish-food chain, namely
diatoms, and also excretes large amounts of ammonia, which is linked with
massive fish mortalities.
Earlier, the increase in algal patches was linked to coastal
pollution from major Indian cities along the west coast. However, say
researchers from the Indian National Centre for Ocean Information Services
(INCOIS)—a Ministry of Earth Sciences (MoES) body—and the US’ National Oceanic
and Atmospheric Administration (NOAA) – “global warming conditions” may instead
be responsible.
A warming ocean means greater temperature differences among
layers of the sea water and this slows the upward transport of nutrients like
silicate from the ocean bottom, lowering its concentration at the surface.
Diatoms growing in surface water need both sunlight and silicate to build their
glass skeletons and thus, will fail to thrive when silicate becomes less
available. On the other hand, Noctiluca remains unaffected by these changes and
additionally will prey on the remaining diatoms. “Remarkably, the waters in the
study area were observed to have sufficient oxygen clearly opposing any linkage
between low oxygen and Noctiluca growth. Intensifying global-warming conditions
thus may be expected to disrupt the fish-food chain and cause a decline of
fisheries in the region,” the researchers said in a statement. The findings
have been published in the peer-reviewed journal, Harmful Algae, said SC
Shenoi, Director, INCOIS.
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