Lake deemed unsuitable for algae harvesting

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Arthur Max / the associated press archives An algae farm in Borculo, east Netherlands, produces material for numerous products.

Commercial algae harvesting, being done in other parts of the world, can produce food ingredients, fertilizer, bioplastics, dyes and colourants, pharmaceuticals and fuel.

Michelle Armstrong, director of the water science and management branch with Manitoba Water Stewardship, said the government and the Water Stewardship Board have looked into the possibility of algae harvesting.

"Most other examples of algae harvesting are done in controlled, small ponds," said Armstrong. "With Lake Winnipeg being the 10th largest freshwater lake in the world, the sheer size of the lake makes the prospect of algae harvesting difficult."

In a small pond, those monitoring the growth of algae blooms can control which sorts of algae are present. On a lake of this size, there are changes in the species of algae that grow throughout the year, and some contain toxins that if used for nutritional supplements once harvested, could be very bad for people's health.

It also cannot be predicted where in the lake a bloom might occur, and some parts of the lake, such as the North Basin, could be hard to get to, especially with harsh weather conditions.

Although some forms of algae that do appear on Lake Winnipeg are the type that can have oil extracted from them, other types have very low oil content, and it would not be worth the financial input to process.

Armstrong said the Water Stewardship Board has considered several options on how to keep Manitoba's waterways clean, but have not conducted any formal studies on the feasibility of harvesting algae on Lake Winnipeg.

"The focus right now is the reduction in nutrients causing the blooms," said Armstrong.

Arne Elias, director of the University of Winnipeg's Centre for Sustainable Transportation, has reported research into deriving biodiesel from algae may make it possible to create even more efficient blends in the future, but it does not seem likely Manitoba will be able to kill two environmental problems with one stone by collecting Lake Winnipeg algae for biodiesel-production purposes.

"Algae used for biodiesel research is grown in closed tanks or open ponds, not harvested from the wild," Elias said.

The government announced last week it is implementing new rules on livestock waste. The rules include a complete ban on winter spreading of manure on Manitoba farms by 2013.

As well, all new pig producers must file manure management plans with the province that include minimum capacity for manure storage.

The issue is that livestock waste contains phosphorus, and when phosphorus builds up and drains from the land into groundwater, final destinations of this polluted water, such as Lake Winnipeg, get unintended side effects such as algae blooms.

eva.cohen@freepress.mb.ca

Republished from the Winnipeg Free Press print edition November 2, 2009 B3