Bugs in the sludge at water?s edge can tell a lot about a lake?s health.
Temperature, bacteria levels and, of course, zooplankton and phytoplanton can also be revealing.
From a 14-foot boat on Lake Kittamaqundi in Columbia, state Department of Natural Resources biologists took water and mud samples Thursday to test the lake?s health.
The lake was one of four in Maryland ? and 909 across the country ? that are part of the U.S. Environmental Protection Agency?s National Lakes Survey. Another lake is being tested as a reference lake.
The lakes were selected at random and all are at least 1 meter deep and more than 10 acres, according to the EPA.
DNR staff have been trained by the federal agency to take samples and record data.
“We?ll get a snapshot all across the country,” said Ron Klauda, DNR?s director of the monitoring and nontidal assessment division.
“With an array of things being measured, we should be able to pinpoint problems that might show up.”
If bacteria levels are too high, sewage input may need to be fixed, he said.
The survey assesses water quality, recreational indicators and stressors such as nitrogen, according to the EPA. Lakes will be determined to be in good, fair or poor condition.
At Lake Kittamaqundi, three biologists used an integrated water sampler ? basically a giant straw made of PVC pipe ? to test the water and a sediment corer to dig up mud from the lake bottom. Temperature, pH and oxygen levels were tested and recorded.
“This is our last lake,” biologist Tim Herb said, adding they were in Salisbury Wednesday.
The days are long at the lakes ? about 10 to 12 hours ? as they gather samples from the boat and at 10 different spots around the water?s edge, Herb said.
Activity on the shoreline can be a better long-term health indicator, since the water quality can vary day to day. Some bugs on the shoreline are good, and those won?t survive along an unhealthy lake, said biologist Ann Schenk.
The samples will be sent to labs for analysis, and a report is expected out in 2009.
AT A GLANCE
Four Maryland lakes are being tested for the National Lakes Survey:
– Lake Kittamaqundi in Columbia, Howard County
– Lake Louise near Grantsville, Garrett County
– Lake Habeeb in Rocky Gap State Park, Allegany County
– Jackson Pond near Salisbury, Wicomico County
Piney Run Reservoir near Eldersburg, Carroll County, is being sampled as a reference lake.
Source: Maryland Department of Natural Resources
For the survey, field crews are measuring:
– Temperature, dissolving oxygen, nutrients, chlorophyll a, water clarity, turbidity and color
– Condition of the habitat along the shoreline
– Zooplankton and phytoplankton that are microscopic animals and plants in the water, which are an important part of the food chain
– Aquatic macroinvertebrates that are small animals such as insects and snails, which are a source of food for fish and birds
– Bacteria that are indicators of fecal contamination from animals or humans
For more information, visit www.epa.gov/owow/lakes/lakessurvey
Source: U.S. Environmental Protection Agency
