Whale Watching in Hermanus

Hermanus is regarded as the whale watching capital of South Africa. By Land - By Boat - By Air

Old Harbour in Hermanus

The Old Harbour Open-Air Museum is a provincial heritage site. It is unique in that apparently it is one of only two fishing harbours in the world that has been conserved in tact.

Learn More

Hermanus Cliff Path

meanders for almost 11 kilometres along the coast from the New Harbour in the west to the estuary at the mouth of the Klein River in the east.

Learn More

Hermanus in the heart of the Cape Whale Coast of South AfricaContact Us

Red Tide, Blue Tide: Bioluminescence in the Ocean

Tuesday, 01 March 2016
Author: linda
Page Views: 24014

Red tides, which often contain harmful algal blooms (HABs), are caused by chemical reactions that occur between algae and other substances. Red by day, blue by night, this colorful ocean phenomenon is a relatively rare natural occurrence that has spawned a number of imitations in movies and literature, the most recent example being a rather striking scene in the visually-driven movie Life of Pi.

algae bioluminescence sparkling coast

Although naturally occurring, red algae blooms can be hazardous to swimmers, animals and marine life. Depending on the algae species, the red tide can contain high levels of ammonia that cause rashes and eye irritation. Poisonous algal blooms rob organisms of sunlight and oxygen, and may emit poisonous toxins.

algae dangerous red tide

Bioluminescent algae blooms (like the ever-popular dinoflagellate marine algae called Sea Sparkle) are most frequently observed away from shorelines. Though beautiful in the dead of night, during the day these blooming phytoplankton are less than stunning. They often turn ocean water red and murky, and emit a distasteful smell of decay that comes from the algae starving the water of oxygen.

algea red tide waves

Visible only in the dead of night, phytoplankton emit a soft bluish glow when disturbed, due to a specific chemical reaction that takes place between the algae and surrounding oxygen. Similar to the glow of a lightning bug, the algae glow can be seen within crashing waves, following boat movements and other disturbances in the water.

algae bioluminescence lone tree