Sea sparkle behind coastal glow

WWF-Pakistan has clarified that the greenish hue and glowing lights observed at night in the coastal areas of Karachi and Balochistan, which had caused concern among fishermen and local residents, are a natural phenomenon known as sea sparkle (Noctiluca scintillans).

The unusual sight had prompted some people to link it to toxic algae or coastal pollution. However, WWF-Pakistan explained that the phenomenon is natural, non-toxic, and influenced by seasonal factors.

Sea sparkle is caused by tiny floating organisms that sometimes appear green, red, orange, or colourless. On Pakistan's coasts, the green and orange hues are common. The green colour is due to symbionts called Protoeuglena noctilucae, which are capable of photosynthesis. These organisms are also responsible for the bioluminescent glow seen at night.

Muhammad Moazzam Khan, Technical Advisor at WWF-Pakistan, stated that the current bloom poses no toxic threat and there have been no reports of fish deaths. Since 2012, nearly all observed Noctiluca blooms in the region have been non-toxic. While temporary odors may arise as blooms dissipate, this is a natural process and unrelated to pollution.

Khan also highlighted that, separate from this natural phenomenon, Karachi's uncontrolled waste, sewage, solid garbage, and oil reach the sea daily through the Lyari and Malir rivers, posing a major threat to marine life and coastal communities.

WWF-Pakistan urged the government to ensure effective management of sewage and industrial waste, improve treatment plants, and monitor coastal water quality to safeguard the country's marine ecosystems and the future of fishing communities.