This summer, signs began popping up next to cottages and summer homes that surround the 9,900-acre lake reading, “Love Your Lake: Skip the Fertilizer.”

The signs, which encourage homeowners to stop using nitrate-rich fertilizer on their lawns because it seeps into the lake, were funded by the Higgins Lake Foundation. The nonprofit also has sponsored research into the water quality of the lake and funded two boat washes to stem the spread of invasive species. In recent years, divers have detected zebra mussels and vegetation-suffocating plants such as Eurasian watermilfoil and the starry stonewart in the lake.

“The (signs) are one of many attempts to get people to take individual responsibility and do what they can do because bit by bit, chunk by chunk, we are beating up our lakes,” said Vicki Springstead, chairwoman of the Higgins Lake Foundation.

No doubt, reducing fertilizer will help, especially if conservation efforts prompt residents to think about their role in their environment, said David Hyndman, a professor of hydrogeology and chairman of Michigan State University’s Department of Earth and Environmental Sciences.

But the biggest impact in reducing algae would be for surrounding communities to switch from septic to sewer systems, he said. Northern Michigan lakes are highly unlikely to experience algae trouble on the scale of Lake Erie – which is covered by a bloom or sheen of algae that is eight times the size of Cleveland – but research has shown that waste from septic systems increasingly is making its way into lakes and rivers, Hyndman said.

“Switching to sewers is a long-term good investment for the water quality of these lakes,” he said.

Statewide, 1 in 3 homes rely on septic systems, which have led to elevated fecal bacteria in 64 Michigan watersheds, according a 2015 Michigan State University study published in the Proceedings of the National Academy of Sciences.

More than 130,000 septic systems are believed to be failing in Michigan, one of the only states without uniform septic codes, despite several efforts at reform.