Confirmed: Manila Bay's Turquoise-Blue Waters Caused by Pollution
There was much buzz online when photos and videos of Manila Bay with surprising turquoise-blue water came out on March 25. Some people thought it was proof of how nature is healing itself, but others were more doubtful. Now, science confirms the phenomenon wasn't one meant for celebration: satellite images show that the change in the color of Manila Bay is caused by high water pollution.
Satellite images showing turbidity and chlorophyll-a concetration in Manila Bay from March 13 to 28. PHL Microsat
In a post by PHL Microsat, a local science program that launched the Philippines' first microsatellite, satellite images from the European Space Agency’s Sentinel-2 and Sentinel-3 showed the estimated chlorophyll-a concentration and water turbidity in the area from March 13 to March 28. High water turbidity indicates high water pollution, while high chlorophyll-a concentration indicates abundance of algae.
Images show high turbidity in Bacoor Bay in Cavite and the mouth of Pasig River. Considering wind direction and water circulation, both these waterways could have affected the waters of Manila Bay. PHL Microsat
Bacoor Bay is surrounded by resorts, factories, and other residential and commercial units. This also includes former Island Cove Wildlife Sanctuary, which was transformed into a Philippine offshore gaming operator hub in 2019. Google Maps
The images show that both factors were already high as early as March 23, but turbidity levels spiked up on March 25—the same date when there was major discoloration in the area. Turbidity is especially at a red-alert level in Bacoor Bay, which may have influenced the waters of the neighboring Manila Bay. There were no changes in chlorophyll-a levels, which means algal bloom wasn't the cause of the incident.
This story originally appeared on Spot.ph. Minor edits have been made by the Esquiremag.ph editors.