Not all vegetative blooms are what we necessarily want or need. The late summer ragweed kicks up miserable allergic reactions for a lot of individuals, while sunflowers can make the skin itch. But these are fairly minor problems compared to the dreaded red tide blooms in the saltwater and the sickly green-colored algal blooms that threaten the health of lakes.

The keepers of ponds and lakes work hard to keep the latter at bay. This requires constant vigilance, as the 300-plus members of the Megunticook Lake Association (stewards and property owners along Megunticook Lake and Norton Pond in Camden, Hope and Lincolnville) know well. So does the town of Lincolnville, which is also ramping up its efforts this summer to keep Norton Pond a healthy body of water.

While Norton Pond is relatively small, 133 acres in size, and shallow (its deepest point is 60 feet), it is rimmed by 87-plus cottages, most of them summer homes. And it is well-loved, with its loons and narrow passageway into the larger Megunticook Lake.

Mainers love their lakes and ponds, and wax eloquent about their ability to soothe, their habitat and wildlife, their beauty through every season of the year. But as the love builds, everyone wants to be near them and their fragility increases.

In the Midcoast, current old-timers remember the state of Chickawaukie Lake in the mid-1980s, when phosphates from laundry detergent, dirt from road construction, and fertilizers and sewage from faulty septic systems ran directly into the water, causing a large and annual algal bloom in what was formerly one of the state’s prettier great blue ponds. In a defensive move, the state sprayed the bottom of Chickawaukie in 1992 with aluminum sulfate and sodium aluminate to block the release of phosphorous, which can lead directly to algal blooms.

Chickawaukie was not the first Maine lake to get treated so: in 1978, Annabessacook Lake, to the west of Gardiner, was sprayed with alum, and later, the Environmental Protection Agency paid for two alum treatments to Cobbossee Lake, near Augusta.

What is so bad about those blooms?

According to the Maine Department of Environmental Protection, the green algae are microscopic bacteria that are natural to a lake’s ecology — to an extent. But it is the heavy blooms that can choke the waterways, make humans and wildlife sick to their stomachs, cause skin irritations, and damage livers and nervous systems.

The DEP considers a bloom to be any dense growth of algae that discolors the water. They can be neon green, pea green, blue-green, or reddish-brown color. They can smell, produce scum and discolor the shoreline. In short, they are gross.

The current collaborative effort in Lincolnville by lake stewards, shore front owners and the larger community to stave off algal blooms in Norton Pond is important, and serves as a model to other municipalities that are home to popular lakes and ponds. As Paul Leeper, president of the Megunticook Watershed Association, pointed out, success will only occur if property owners take time to survey their own septic systems, as well as erosion potential from roof gutters, gardens and driveways. Those small efforts will then collectively work to help reduce overall levels of phosphorus.

While there are other factors that contribute to algal blooms — geese, erosion, static water and warm weather — the human factor is the most controllable, and should be the easiest, if we are proactive. Before it becomes necessary to paint another lake bottom with alum.