Karachi Weather Update: Foul Smell Linked to Decaying Phytoplankton

The foul smell spreading across Karachi’s coastal areas has been linked to the decomposition of microscopic marine plants called phytoplankton, according to a WWF-Pakistan expert.

Karachi residents, particularly those living near the coast, reported a strong and unusual smell on Wednesday. Muhammad Moazzam Khan, technical adviser on marine resources at WWF-Pakistan, said the smell is caused by phytoplankton dying and decomposing after changes in marine conditions.

What are Phytoplankton?

Phytoplankton are microscopic marine organisms that live near the upper layers of the sea

They increase during the monsoon season. As the monsoon ends around mid-September, changes in sea temperature, water movement and wind conditions can cause large numbers of them to die. Their remains can then wash ashore and produce a strong smell as they decompose.

End of Monsoon Affects Karachi Coast

Khan said the end of the monsoon and lower wind speeds affect the marine vegetation system. These seasonal changes can increase the amount of decaying marine vegetation along the coast.

The Pakistan Meteorological Department said Karachi would remain hot and humid. It also reported that low pressure over the Arabian Sea had weakened and that sea breezes were expected to return from the evening. Stronger sea breezes can help disperse the smell from coastal areas.

Experts said the phenomenon is a natural seasonal process. The smell is expected to reduce as marine conditions change and sea breezes become stronger.