Ariel McKee

Despite being lovingly referred to as the “sea cow”, manatees are actually the aquatic relatives of elephants. Like them, manatees are herbivores, subsisting primarily on marine and freshwater plants.
One of the ways in which they contribute to the balance of their ecosystem is by cutting and spreading the seeds of sea-grasses to promote optimal growth, much like birds and squirrels cultivate plants through seed distribution on land.

Along with vast portions of sea-grass, manatees eat seaweeds. Specifically, algae – and lots of it. This consumption is fine when ingesting the green, stringy algae commonly found on the surface of pond water.
However, in Florida’s coastal waters, where approximately 5,000 manatees reside, there have been outbreaks of toxic algae known as blue-green algae. Toxic algae occur from excess nitrogen and phosphorous, which fertilize the water. This is often the result of poorly managed sewage and agricultural runoff, which contains—among other substances—pesticides, chemical fertilizers, and animal waste.

Unlike other algae, blue-green algae have a paint-like texture and appearance, often turning waters a discerning shade of mildew green. These algae are extremely dangerous to humans and surrounding wildlife upon contact. Once you consider that manatees, who love algae, weigh an average of 1,500 to 1,800 pounds and the fact that they consume, on average, a tenth of their weight per day, the problem becomes clear.

In addition to posing public health hazards – or rather because of this – algae blooms damage the economy as well, with current outbreaks critically hurting the tourist and hospitality business through the loss of leisurely activities, like canoeing, swimming, and fishing.