Agricultural Fertilizers and Manure are Major Source of Excess Phosphorus Pollution – A Contributor to Destructive Algal Blooms – In Lake Erie

Comprehensive assessment shows current and past agricultural fertilizer and manure applications are largest single source of excess phosphorus to western Lake Erie basin

Bold action is needed to identify and implement management approaches to restore health of Lake Erie

News from the Canada-U.S. International Joint Commission

Posted February 14th, 2018 on Niagara At Large

One of the signs posted in recent years along the shores of Lake Erie

In a report released this February  by the International Joint Commission titled Fertilizer Application Patterns and Trends and Their Implications for Water Quality in the Western Lake Erie Basin, an extensive analysis of existing data leaves little doubt that commercial fertilizer and manure applications are the largest sources of excess phosphorus into the western basin of Lake Erie.

Dead fish washes to shore in Lake Erie waters choking with algal blooms

The IJC Science Advisory Board’s Science Priority Committee completed the assessment to better understand the influence of past, current and possible future nonpoint agricultural runoff of phosphorus into western Lake Erie, and their potential to cause eutrophic conditions and nuisance and harmful algal blooms (HABs). The area studied included the lake’s binational western basin as well as the St. Clair-Detroit River system, which feeds directly into Lake Erie.

Commercial fertilizer is the primary source of phosphorus from agricultural sources into the western basin overall and in the United States, while in Canada manure and commercial fertilizer are relatively equal sources.

Given that the most recent comparable binational data are from 2006-2007 and that there are no well-established methods for distinguishing phosphorus loads from fertilizer versus manure in the laboratory, more specific fertilizer sales and application data as well as manure generation and application data are needed to advance our understanding of specific agricultural sources.

The analysis also showed that excess phosphorus from fertilizer application that is stored in agricultural soils and nearby ditches, buffer zones and wetlands has the potential to contribute the nutrients for years or even decades.

A destructive blight, robbering the waters in Lake Erie of life-supporting oxygen.

“Even a small ‘leakage’ of excess phosphorus may be sufficient to contribute to algal blooms,” the report says.  Fortunately, the study found that following a period of phosphorus accumulation in soils, since the 1980s fertilizer application at a watershed scale is roughly balanced by phosphorus removal in harvested crops.

The expansion of conservation tillage, such as no-till, correlates with the rise of phosphorus entering the lake, because the nutrient accumulates in the soil’s uppermost layer. The widespread use of subsurface artificial tile drains also may increase rates of phosphorus entering the lake.

Thus, although both these practices have associated benefits, they may be important contributors to the development of HABs. Additional research and monitoring is needed to quantify both sources and to explore new approaches to these practices to reap the benefits intended without increasing nutrient inputs into Lake Erie.

Climate change is expected to influence the rate of phosphorus entering Lake Erie. Years of high precipitation and warmer water temperatures can result in larger discharges of phosphorus from agricultural lands and faster development of HABs, as well as longer recovery timeframes.

Again, additional monitoring is needed to evaluate climate change impacts on nutrient inputs and to adapt management actions that will meet targets for nutrient reductions into the western lake basin.

Finally, the report notes that the management practices associated with phosphorus application – including timing, rates, and the equipment used – may have a bigger influence on phosphorus release from agricultural lands than the category of fertilizer (commercial fertilizer or manure).

A review of the effectiveness of current management practices is needed, with the goal of developing new approaches to more effectively reduce the input of phosphorus into the lake from fertilizer and manure applications.  The 4R nutrient management program for fertilizer application should be expanded and evaluated for its effectiveness in order to develop new approaches.

“Phosphorus control measures enacted in the 1970s demonstrated that Lake Erie eutrophication could be reversed,” the report states.

“The challenge this time is with agricultural nonpoint sources of nutrients, which will require a different set of responses. Lake Erie has benefitted from bold action in the past and requires similar bold action today to ensure its health and value to the people of the basin into the future.”

As a binational organization created by Canada and the United States under the Boundary Waters Treaty of 1909, the International Joint Commission serves as an independent assessor of the progress made by the two governments to achieve the objectives of the Great Lakes Water Quality Agreement.

For more information, see the full report . An infographic with highlights from the report is below.

Unfortunately, we seem to be going back to the dirty and dangerous times we were facing in the Great Lakes when I was back here, at The St. Catharines Standard, covering the environmental beat more than 30 years ago. Here I am opening a research report on the Niagara River  and Great Lakes at my desk.

An Afterword  from Niagara At Large reporter and publisher Doug Draper – I began my career as a full-time environment reporter at The St. Catharines at the end of the 1970s – a decade where one of the very real concerns in the Great Lakes region was that Lake Erie and much of the fish and other wildlife in it were literally going to die an ecological death from the much the same kind of contamination, from (at that time) both rural and urban sources, discussed in the above International Joint Commission report.

Much work was done by federal, provincial, state and municipal governments in both Canada and the United States to curb the pollution and for decades, improving conditions in the lakes gave experts and lay people alike reason to feel optimistic about the progress and the prospect of these vital water resources for present and future generations.

Now it seem clear that we are slipping backwards and the last thing we need is government leaders like Trump on the U.S. side of the border, and government bodies and politicians on the Ontario side of the border that we see tearing the environmental guts out of agencies like the Niagara Peninsula Conservation Authority – an agency that should, as part of its role, be working with rural landowners and farmers to curb the flow of pollution to creeks and rivers that flow to the Great Lakes.

When we read in the local media recently that the current bunch of political hacks now serving on the NPCA board worked with the Caslin administration in regional government to redraft a Memorandum of Understanding (MOU) between the two parties that compromises and weakens the focus on environmental protection, that is cause for concern.

When that MOU was presented to regional councillors, among those on the region’s council applauding it was Lincoln Mayor Sandra Easton who summed up what is wrong with the thinking of too many of today’s politicians in Niagara this way, according to  recent  news accounts – Lincoln Mayor Sandra Easton called it “high time” that the existing MOU policies were being changed. ”I don’t think there should be any confusion at all about it,” she said. “The other part of this was the blatant personal bias that people (working  at the Conservation Authority) who were not planners were bringing to policy interpretation, because they were more environmentally oriented than others.”

Well, of course, Madam Mayor.  We sure wouldn’t want people who “were more environmentally oriented” working for a Conservation Authority, would we!

This kind of mentality – exhibited by too many of our politicians in the Niagara region – poses as much of a danger to our Great Lakes and environment at large as the pollution discussed in the above report. And for the sake of present and future generations, it needs to be swept out of office in this coming October’s municipal elections – Doug Draper

To read a related story on the redrafted Memorandum of Understanding reached between the NPCA and Niagara regional government, click on – .

Come this October’s municipal elections, remember the following  bunch when you go to vote and mark your ballot for A BETTER NIAGARA.

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 “A politician thinks of the next election. A leader thinks of the next generation.” – Bernie Sanders




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