War on phosphorus to start in Madison in 2013

28 September 2012

Madison, Wisconsin, will host the 2012 meeting of the North American Lake Management Society (NALMS), a group of which I am a member and the only Lake Manager outside of the continental USA accredited by this organization.  Madison’s Dane County has set new goals for cleaner lakes, by targeting phosphorus pollution as from 2013 – as part of a new Clean Lakes, Clean Energy budget announced yesterday.

In recent time, considerable improvements have been made to reduce pollution in the Mississippi River in the reach between St Paul and Minneapolis. There are still problems to be addressed, however, as this report indicates:

The report cited concerns that pollutants, including DDT and lead, could harm the birds and said more tall trees are needed to encourage nesting in the area.  Furthermore, the river, which was nearly devoid of fish in the 1920s, has become a world-class fishery for walleyes, smallmouth bass and mussels, although mercury, PCB and PFC contamination has forced restrictions on fish consumption.

Several other indicators are cause for alarm, the report says:

Urban runoff, drainage from farm fields, and climate change including an increase in snow and rainfall, have boosted the speed of the river by 25 percent since 1976, as measured at the Hastings Dam. The faster flow results in more erosion, a high risk of flooding and an increase in sediment that can choke aquatic life.

Nitrate levels have risen at least 47 percent in the same period. The river still meets drinking water standards, but the nitrates mostly from farming feed algae blooms that suffocate marine life in the Gulf of Mexico.

Invasive Asian carp species are advancing upstream and could have a disastrous impact on aquatic life, boating and fishing. It’s not clear if the carp have established breeding populations in the metro area yet but there’s DNA evidence that they’ve reached the Coon Rapids Dam.

Pharmaceuticals and industrial contaminants could threaten human and aquatic health in ways that aren’t yet fully understood. They include triclosan, a germ-killer used in disinfectant soaps, toothpaste and cosmetics, which can contribute to the emergence of resistant strains of bacteria and whose presence in the river has increased by up to 300 percent since 1963.

Up in Canada, algal problems have been reported in Moose Jaw’s Buffalo Pound Lake.  The treatment works uses alum to manage the problem – a process that lowers the pH of the water and causes corrosion in pipes – especially the older types of metal pipes.

Toxins from golden algae have reportedly been responsible for the deaths of fish in Roosevelt Lake, Phoenix (Arizona).

Apparently Michigan has had lots of algal blooms over the years but without any toxins having been recorded.  Maybe because they have not been looking for them?  Their Hamlin Lake is currently in the news right now.  Its important to remember that blue-green algae produce a lot of nasty compounds – so its almost impossible to say that there are no toxins present!  More correctly, managers can at best report on what they looked for – which is most likely to just be the microcystin group.

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