ALBANY, N.Y. — A conservation group says $100 million of conservation measures are needed during the next decade to protect New York’s Finger Lakes, where five of the waterways had significant outbreaks of toxic algae last year.

In a report released this week, The Finger Lakes Land Trust said agricultural runoff and the warming climate are lowering water quality. It’s advocating buying land and conservation easements to help buffer the 11 waterways, create new wetlands, preserve farms, protect drinking water and leave remaining shoreline undeveloped.

“Soil erosion from farm fields and contamination from lakeshore septic systems both increase the likelihood of future toxic algal blooms,” the report said. “All 11 lakes are at risk.”

The algae can cause nausea and throat irritation if swallowed. It also can cause and skin and eye irritation and can make animals sick.

Last year, it affected parts of two smaller and shallower lakes that warm more readily — Conesus and Honeoye — and deeper, colder Owasco, Canandaigua and Seneca lakes.

The trust manages or monitors nearly 20,000 acres of nature preserves and easements in 12 counties, about one-third of them open to the public. The report was based on a yearlong assessment with input from 40 other nonprofits, county and regional planning departments and government conservation agencies.

The state Department of Environmental Conservation maintains online listings statewide of harmful algae blooms and showed 125 last year. They ranged from Central Park Lake in Manhattan, on the list for 22 weeks, to Lake Placid in the Adirondacks, listed for five weeks.

“It’s a much broader phenomenon,” said Andrew Zepp, trust executive director. “It’s whatever moves dirt and nutrients into a lake.”

For the Finger Lakes, long known for their clean waters, the issue is critical, according to the trust. The lakes provide drinking water for a million people in western New York and support an estimated $2 billion in annual tourism alongside $1 billion in agriculture.

Last year’s especially wet spring washed lots of nutrients into the lakes followed by a warm and sunny summer, while this year’s relative drought meant less runoff, Zepp said.

Blooms were found this year in Cayuga, Honeoye, Canandaigua, Seneca and Owasco, according to the DEC. The agency said Friday anecdotal reports indicate blooms have increased in frequency and duration within the last decade, but a well-documented record is lacking.

New York is spending more than $5 million to study why blooms are happening in Owasco Lake and doing projects in its watershed to reduce them, DEC spokeswoman Erica Ringewald said. The state will keep working with local officials to find effective ways to reduce occurrences in the Finger Lakes and across New York, she said.

The trust has contacted state conservation, parks and agriculture agencies about possible funding, Zepp said. They’re looking into federal funding and possible private support as well.