Barnum Pond, north of Paul Smiths, has had harmful algal blooms several times, including last year. (Enterprise photo — Justin A. Levine)

The state Department of Environmental Conservation has revamped the way people can find harmful algae blooms (HABs), and the department is encouraging the public to learn more about them as water and air temperatures warm.

The DEC says HABs are increasing in number, with more than 400 reported statewide since 2012. While HABs are not always harmful, the DEC — and its numerous partners, including the state Department of Health — said the public should be aware of HABs and avoid them if possible.

“Most algae blooms are harmless. However, exposure to toxins and other substances from certain HABs can make people and animals sick,” a press release from the DEC said. “The increasing frequency and duration of HABs also threatens water quality and recreational use of waterbodies essential to ecosystem health and statewide tourism.

“DEC and the DOH continue to lead the most comprehensive HABs monitoring and reporting program in the nation. Hundreds of waterbodies are monitored annually by DEC, DOH, State Parks, academic institutions, and volunteer monitoring partnerships,” the release continued. “Additional public health protections are provided by DOH oversight of regulated beaches and public water systems.

“While the exact cause of HABs is not fully understood, HABs usually occur in waters high in phosphorus and/or nitrogen. New York State has many programs and activities to reduce phosphorus and nitrogen from entering the water from surrounding lands, including stormwater permitting programs, funding for water quality improvement projects, and a nutrient law that restricts the use of phosphorus lawn fertilizer.”

The DEC used to have a spreadsheet-like form that listed HABs, but now it has a statewide map with different colored dots denoting them. Barnum Pond, near Paul Smiths, had a suspected HAB last year, and Eagle Pond — just south of Lake Titus in Duane — has a persistent bloom that is already marked on the DEC’s new map.

Eagle Pond is the only current HAB in the Adirondack Park, while there are about a half-dozen statewide. HABs tend to occur later in the year, when water levels are lower and temperatures are warmer.

“HABs are likely triggered by a combination of water and environmental conditions that may include excess nutrients (phosphorus and nitrogen), lots of sunlight, low-water or low-flow conditions, calm water, and warm temperatures,” DEC spokeswoman Erica Ringewald told the Enterprise last year. “Depending on the weather and the characteristics of the lake, HABs may be short-lived (appearing and disappearing in hours) or long-lived (persisting for several weeks or more).”

Because of the increasing number of HABs, Gov Andrew Cuomo called for a task force last year that has since developed detailed plans for 12 lakes in the state that “are vulnerable to HABs, are critical sources of drinking water, and are vital tourism drivers,” the DEC’s HAB website says.

Lake George and Lake Champlain are included in the 12 priority lakes. The action plans are detailed and about 100 pages long, including a history of the lakes as well as how each lake will be monitored going forward.

While Lake George does not have a history of HABs, Lake Champlain will often have several going on at the same time in different parts of the lake. DEC shares management responsibility for Lake Champlain with several federal agencies and the state of Vermont.

“Lake Champlain has been the focus of increasing concern by numerous state agencies, non-governmental organizations, community interest groups, lake users, and other stakeholders given the increase in the extent, duration, and impacts of HABs at various locations in the lake,” the HAB action plan for the lake says. “As described throughout this Action Plan, a primary factor contributing to HABs in the waterbody is excess nutrients, in particular, phosphorus. Total phosphorus (TP) is a common metric of water quality and is often the nutrient monitored for and targeted in watershed and lake management strategies.”

In response, the plan calls for a number of specific actions including working with farmers to limit the amount of runoff produced, rethinking roadway and storm drainage, and implementing a manure management system for farms with livestock.

To learn more about HABs, see the new map or report a suspected HAB, go to www.dec.ny.gov/chemical/83310.html.