[USA] Lake Erie’s harmful algal bloom problem can be reversed, but it will likely involve a massive effort to get all farmers to follow good conservation practices to avoid the polluted water runoff from farms feeding the blooms, a new study says.
The study, led by University of Michigan scientists, suggests that the traditional practice of encouraging voluntary conservation efforts may not be enough and says that mandatory conservation practices may be needed.
“Our results suggest that for most of the scenarios we tested, it will not be possible to achieve the new target nutrient loads without very significant, large-scale implementation of these agricultural practices,” said Don Scavia, an aquatic ecologist at the University of Michigan and the lead author of the new study, “Informing Lake Erie agriculture nutrient management via scenario evaluation.”
“It appears that traditional voluntary, incentive-based conservation programs would have to be implemented at an unprecedented scale or are simply not sufficient to reach these environmental goals, and that new complementary policies and programs are needed,” Scavia said.
The blue-green harmful algal blooms in Lake Erie can produce toxins that threaten the local water supply and also threatens the region’s tourism and fishing industries. Last year’s bloom in the lake was the biggest ever.
While phosphorus, the chemical that feeds harmful algal blooms, can be produced by sewer systems and by commercial activities, the report says that changing farming practices is the key to fighting Lake Erie’s harmful algal blooms
“The main driver of the harmful algal blooms is elevated phosphorus from watersheds draining to Lake Erie’s western basin, particularly from the heavily agricultural Maumee River watershed. About 85 percent of the phosphorus entering Lake Erie from the Maumee River comes from farm fertilizers and manure,” says a University of Michigan press release describing the new study.
Adam Rissien, clean water director for the Ohio Environmental Council, told the Register Tuesday it probably will be necessary to require all farmers, not just the ones who are particularly interested in conservation, to follow good conservation practices.
That would include making it mandatory for all farms to develop a pollution prevention plan that includes soil testing and a field-by-field study of the most effective approaches, including putting in buffer strips of grass next to farm fields and taking some fields out of production and replacing them with grass.
The report offers a number of different scenarios for achieving a 40 percent reduction of phosphorus in Lake Erie, a goal that’s been set by U.S. and Canadian officials.
One scenario involves taking 30,000 acres out of production in the Maumee River watershed, and putting more than 1.5 million acres under strict conservation practices.
The practices that the scientists discuss in their report are already being carried out, Rissien said. The key is getting all farmers to do what only some farmers are doing now, he said.
“We need broad scale adoption of effective practices,” Rissien said.
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