Massive red tides in Hong Kong summer 2011

[DocMartin Williams]

Red tides are extremely evident in Hong Kong just now; perhaps resulting from combination of calm hot weather, long hours of sunshine, and excess nutrients from pollution.

Here's a swirl of froth of red tide by Kwun Yam Wan beach, east Cheung Chau. This is one of several Hong Kong beaches that have been closed at times in recent days.

I've also seen reports of red tides north of Lantau (seen by dolphin watchers), off southern and eastern Lantau, and off s HK Island. Seen red tides for myself, too; on ferry rides between Central and Cheung Chau, as well as Deepwater Bay and Shek O on Hong Kong Island.

This shows froth from red tide algae stirred by propellers of ferries, just to northwest of Cheung Chau.

I've emailed the Agriculture, Fisheries and Conservation Department re the red tides; received these replies:

Quote:

Thank you for your email.

This department received numerous red tide sightings since mid August hit the southern and western waters of Hong Kong including more than 20 beaches at Tuen Mun, Tsuen Wan, Ma Wan, Lantau, Lamma and Hong Kong Island; as well as the waters from Nim Wan, Ma Wan, Lantau Island, Soko Island, Cheung Chau, Lamma Island, Hong Kong Island, Victoria Harbour, Tung Lung Chau and Po Toi including. The red tides were formed by Protopolykrikos distortus which was rare in local waters. We will closely monitor the situation until the red tides were dissipated.

Thank you very much for reporting red tide incident to us. We count on your continuous support.

Quote:

Thanks for the sharing.

We found this dinoflagellate every year in Hong Kong waters, but in low frequency. It bloomed a few times before, so possibly the cysts are here.

I also received some photos and reports from other members of the public, that really let us know more about the bloom. Thanks again.

You can find info – and send reports – via AFCD's Red Tide Information Network.

Worth a read for background info: A General Review of Red Tides in the South China Sea.

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