Sunday, September 30, 2007
ALGAE AND THE LAKES
Since 2002 a Halton Region advisory committee has been quietly working on the nuisance algae problem.
I’m a member that committee - the Lake Ontario Shoreline Algae Action Advisory Committee (LOSAAC. The group is putting the finishing touches to a report going to Council.
This “nuisance” problem is primarily an odour. A stink this summer lasted 8 or 9 weeks - longer than in recent memory. Caused by an aquatic plant called Cladaphora the smell won’t kill us – but we should be concerned.
I am not a Scientist but.....
The science to the smell is this:
· Wastewater treatment and other human activities put phosphorous into the lake.
· An invasive species, zebra mussels, clean the water, ingest large quantities of phosphorous, and then poop it out on the lake bottom where it sits ready to help the algae grow.
· Population growth means we are putting more phosphorus into the lake. Conservation Halton, using actual flow measurements and water sampling, has calculated that we dump 13,611 kilograms of phosphorus into the lake each year. A scientific team working with LOSAAC says when we are built out we’ll be loading 23,192 more kilograms into the lake each year making it a more attractive place for cladaphora growth and smellier too.
Invasive species, phosphorous, hardening of the shoreline and population growth all contribute to the algae problem but there is a bigger picture.
Beware of Invasive Species
In 2005 several scientists put out a paper called Prescription for Great Lakes Ecosystem Protection and Restoration. They claim that we are at a ”tipping point of irreversible changes.” Areas of the lakes are experiencing ecosystem breakdown. Stresses have overwhelmed natural processes “that normally stabilize and buffer the system from permanent change.”
There is some improvement (e.g. contaminant trends going down, the return of bald eagles and cormorants) but the overall trend is disturbing.
“The near-shore aquatic system has lost its ability to adapt to changes, loss of shoreline, the destruction of wetlands, and urban and agricultural run off. These trends are accelerating.”
In one of several workshops organized by the province’s Environmental Commissioner and Pollution Probe held about a year ago one participant noted:
“The problem isn’t invasive aquatic species, toxics, climate change, or any
other of the many issues we face. The Problem is us. Our lifestyle has to adapt to the environment. Until we humble ourselves, and understand that we are the invasive species, we won’t get it.” (A Public Dialogue on the Future of the Great Lakes.)
I’ll return to algae and the Great Lakes in future postings.