LEA and Bates Researchers Working Together to Study Gloeotrichia on Long Lake
January 22, 2012 -
Naples-This past summer LEA partnered with researchers at Bates College to study gloeotrichia populations on Long Lake. Pronounced glee-o-trick-e-a, these tiny planktonic specs in the water column are visible to the naked eye and are thought to play a key roll in nutrient cycling and the “greening” of our lakes.
Different from LEA’s regular water-testing routine at the deepest part of the lake, gloetrichia sampling takes place in the coves and shallows around the edge. These areas typically have more nutrients, productivity and variability compared to the center, but it is also the water that most people see and come in contact with on a regular basis.
To ascertain gloeotrichia populations, finely sieved conical nets were pulled up through the water column to catch and concentrate these organisms into small vials for later analysis. In August, small battery powered temperature and light meters were also deployed at tow of the sites to better assess conditions.
Laurie Griesinger, a research assistant from bates helped train LEA staff and pick the sites for sampling. Sites at the north and south end, Cape Monday and one on the western shore were eventually chosen to give a wide spectrum of conditions in Long Lake.
Not true algae, gloeotrichia are essentially bacteria that derive energy from the sun. They belong to a group of organisms called cyanobacteria, which were long considered blue-green algae because of their photosynthetic properties. Cyanobacteria are one of the most studied “algae” because they are often responsible for the rapid and overwhelming blooms that turn some lakes into a seemingly impenetrable, deep green mat from August to November.
Gloeotrichia are particularly interesting because they are thought to pull the nutrient phosphorus from the bottom sediments and then float up to the surface waters to grow and reproduce via photosynthesis. This cyclic pattern gives them an advantage over other algae and may bring usable phosphorus into the water column that was previously unavailable.
When found in large enough quantities, gloeotrichia can be dangerous as it causes digestive problems, skin irritations and is toxic to the liver. Griesinger, who has sampled all over this region, said that preliminary results from the study indicated that gloeotrichia populations in Long Lake appear to be average. In some of the water bodies just a few miles south of Long Lake, high populations were found and Laurie experienced first hand some of the rashes and skin irritation that locals were reporting all summer.
In conjunction with Bates College, LEA is likely to continue studying gloeotrichia populations on Long Lake next year. However, because of common reports of increased algae growth along shoreline rocks and boat hulls, LEA may also be looking into studying gloeotrichia on some of our other water bodies.
Colin Holme, LEA Lakes News, January 2012
Lakes: Long Lake
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