A red tide in the waters of Shenzhen Bay was spotted on Sunday with an area of six square kilometers. The water was a light reddish-brown. No fish had died.

The phenomenon is caused by algal blooms discoloring water under specific environmental conditions.

The red tide significantly decreased as of Monday, falling to 0.2 square kilometers.

April and May are a high-frequency periods for red tides because of the sudden rise in temperature.

The two algae in the red tide have been tested as non-toxic. The red tide will not affect other areas as it only occurs at Shekou Fishing Port in Shenzhen Bay where there is a slow water current.

(Photos are screenshots)

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