Wednesday, April 23, 2014 10:30 AM
Published on: Thursday, August 01, 2013
By Donna Broadway
ROCKVILLE – Montgomery County Department of Parks officials are warning visitors to be cautious when visiting Lake Needwood at Rock Creek Park.
Officials said a high level of microcystin, a toxic cyanobacteria produced by blue-green algae was detected in the lake. This is the second year in a row that elevated levels were detected in the water.
The algae growth is attributed to warmer summer temperatures, calm waters, sunlight and phosphorus growth. Levels are expected to taper off once the temperature cools.
According to the Maryland Department of Natural Resources, microcystin may resemble spilled green paint on the surface or small flakes or balls. If the algae is blown by wind or pushed by currents into higher salinity waters where it cannot survive, it generally takes on a greenish-yellow color and a chunky appearance as it dies.
“We have posted signs around Lake Needwood and urge visitors to please pay attention to these precautions to avoid any harm from microcystin,” said Jai Cole, principal natural resource specialist for the parks department. “Portions of the lake may be contaminated for the rest of the season. We will continue to monitor and update signs when the warning is lifted.”
Water that contains microcystin can cause severe liver damage if ingested. Visitors are asked to avoid all contact with the lake water, and dogs or other pets are not allowed to swim in or drink from the lake since pets are at risk for algae-related liver poisoning if they swim in or drink lake water.
Park officials advise visitors to keep dogs on leashes and to not allow them to drink or go in the water. People are not allowed to swim in Lake Needwood, but fishing and boating are allowed.
Melissa Chotiner, media relations manager for the parks department said one dog was reported sick in 2012. The symptoms from drinking water infected with microcystin including diarrhea, vomiting, visual disturbance, nausea and muscle weakness. Fish and birds are also at risk for microcystin poising, and visitors are advised to eat only properly cooked muscle meat of fish caught from the lake.
If visitors do have contact with the lake water, they are advised to use good hand cleaning practices prior to eating, drinking or smoking.
Chotiner said the parks department has not found a way to stop the algae from growing, but testing is done routinely and they are looking at several options, including adding an island in the lake.