Photo by:  Alicia Photograghy/www.flickr.com/photos/aliciaphotography/2682454915/

Rosy Sunset over Taylor Pond in Auburn, Maine

In September 2012, Lake Auburn in Auburn, Maine, experienced a significant fish kill. Water quality and wildlife officials discovered more than 200 dead trout floating on the lake or along the shoreline. According to an article in the Sun Journal written by Scott Taylor, “higher-than-normal phosphorus levels were behind the fish-killing algae bloom.”

Experts hired by the Lake Auburn Water Protection Commission do not know why the phosphorus levels were so elevated or if such an event will occur in the future. They continue to examine erosion, water temperature readings and a new species of alga, or the combination of two or three of these, as potential causes.
Though phosphorus occurs naturally in the environment, too much may cause an algae bloom. Developed areas, which have more impervious surfaces such as roads, driveways, roof tops, etc., have more storm water run-off. Poor ditching and poor drainage along roads and driveways, failing septic systems and the use of fertilizers also add to the phosphorus levels. An excessive growth of algae consequently clogs our waterways, uses up dissolved oxygen as they decompose, and blocks light to deeper waters.
Temperatures and rain in the spring of 2012 were higher than normal and the ice went out early, giving the upper, or epilimnion level, of the lake a chance to absorb heat and warm up sooner than usual. This is where most flora and fauna live and there typically is a good mix of current and sunshine. At this level oxygen is normally replenished.
The middle layer of a lake is the metalimnion or thermocline region, a layer of water in which the temperature declines rapidly with depth. Between three and ten meters is the thermocline–the transition point at which the temperature and oxygen levels of the lake suddenly change.
The hypolimnion is the bottom layer of colder water. During the summer months, the density change at the thermocline acts as a physical barrier that prevents the top and bottom layers from mixing. Exposure to wind and the lake’s size determine the depth of mixing. Over the course of the summer, in this stagnant lower level, oxygen is gradually depleted by bacteria and bottom sediments.
In this case, according to Taylor’s article, another factor may have had a significant impact: “gloeotrichia, a kind of alga that’s new to Lake Auburn.”  Higher phosphorus levels feed algae. As noted above, when the alga dies and sinks to the hypolimnion level, it’s consumed by bacteria, which uses up available oxygen. With this discovery, we have to wonder if it is a combination of the three components–erosion, temperature and alga–that caused the bloom.
Lake Auburn is a significant lake trout and salmon fishery. With oxygen levels depleted, the fish suffocated.
The lake is a drinking water supply, but we need to remember than an algae bloom is not a threat to drinking water.
In an article about the fish kill published in the LEA Lake News, Lakes Environmental Association’s Executive Director Peter Lowell writes,  “Lake Auburn is now the poster child for climate change showing the effects of a longer open water season and more frequent big rains. These are new factors in play for all Maine lakes. LEA has event-by-event rainfall data going back 30 years that verifies increased storm intensity. The 10-year storm in 1970 terms now occurs about every two years. Eventually, culverts, road ditches and all storm water controls will need to be super-sized to handle the new normal . . . While we deal with the challenge of revamping our concept of storm water control, remember the message about the effects of watershed development and erosion control. The activities in each lake’s watershed determines the health . . . Seeking out those harmful activities and addressing them by utilizing modern BMP methods is the key to lake protection.”
To view lakefront properties for sale on Taylor Pond in Auburn, click on the green box above.
To learn more about Taylor Pond and the nearby Range Ponds, check out the blog links below.
City Amenities in Taylor Pond’s Lakefront Neighborhood in Auburn, Maine
The Range Ponds of Maine – Chain of Three, Nesting Bald Eagles, Quality Fishing