What's The Scoop on Blue-green Algae

Making news again this summer, is the blue-green algae blooms that have been found in Lady Bird Lake at Red Bud Isle, Vic Mathias Shores and Festival Beach[1]. While blue-green algae may not be entirely new to Austin, as it has been here in a limited way for some time, the widespread proliferation of it is a new phenomenon[2].

Blue-green Algae at Red Bud Isle [8]

Blue-green Algae at Red Bud Isle [8]

You might be asking “what exactly is blue-green algae?” We are here to break it down for y’all. Blue-green algae is photosynthetic bacteria, meaning that, like plants, it uses sunlight as an energy source and is dependent on nutrients like phosphorus and nitrogen in its environment for food[3]. It grows best in still, warm water (water temperatures ranging from 77-86 degrees Fahrenheit)[1]. With daily temperatures near or above 100 degrees in Austin, high levels of nitrogen and phosphorous rich runoff pollution[4], and reduced flow speeds in waterways, resulting from a lack of heavy rainfall, conditions are ideal for eutrophication[5].

Blue-green Algae in Lady Bird Lake [7]

Blue-green Algae in Lady Bird Lake [7]

While most blue-green algae blooms do not produce toxins, some can produce cyanotoxins[3]. However, it is not possible to determine the presence of these toxins without further testing[6]. The cyanotoxins can pose a serious threat to not only fish but livestock, pets, and humans as well.

The algae blooms can be filamentous (thin and stringy or hair-like), in patches or clumps, or even be so small it is not visible to the naked eye. If visible, it will form “scum” layer or floating mats on the water surface and can cause blue, green, brown, or reddish-purple oil-like coloration to the water[3].

Oil-like coloration [3]

Oil-like coloration [3]