red_tide, originally uploaded by Laura Urquhart.
Been to the Halifax waterfront recently? You may have seen something like this.
From Red water a puzzler, NS Chronicle Herald:
It looks like weeks of dry weather followed by heavy rains may have brought a phenomenon known as red tide to Halifax Harbour.
The water behind the Maritime Museum of the Atlantic had a rosy hue on Monday. Mayor Peter Kelly said the federal Fisheries Department had taken samples but wasn’t able to process them because of the Natal Day holiday.
He said the department’s guess is the discoloration was caused by red algae.
Marlon Lewis, a professor of oceanography at Dalhousie University, said algae levels in the area around the harbour are the highest he’s seen in two years.
"It’s not a very big (red tide), I wouldn’t say," Mr. Lewis said over the phone Monday. "Not compared to the others I’ve seen where the water turns a kind of brick red."
Mr. Lewis said the algae levels are high, but nothing abnormal for Halifax. He said it probably won’t hurt anything.
When algae die, their decomposition eats up oxygen. Mr. Lewis said in years past the algae levels in the Bedford Basin have been so high that the lack of oxygen has actually killed fish. He said he’s seen lobsters crawl out onto the beach to get away from the choking water.
The recent weather has been great for algae growth, he said.
"We had a big amount of rain a couple weeks ago after a very, very long dry spell," explained Mr. Lewis.
"It was like a big pulse of nutrients coming in."