By Sandy Alexander
WASHINGTON – Frog populations are declining as their habitat disappears in Maryland and frogs with deformities have also been found in the state, making it part of a nationwide trend of troubled amphibian populations, researchers said Wednesday.
Maryland is “doing all right” compared to other states — at this point, no species of frog in the state has disappeared completely, said Sam Droege, an amphibian researcher at the U.S. Geological Survey’s Patuxent Wildlife Research Center in Laurel.
But the extent of the situation is unknown due to a lack of data, Droege said. Now is the time to start counting, so scientists can recognize problems as they arise, he said Wednesday at a Capitol Hill news conference on falling amphibian populations around the world.
That is where Frogwatch USA comes in. Started last spring by Droege and others at the Patuxent center, the national program works with local groups and agencies to recruit volunteer frog-counters, who collect data across the country.
The program posts its results on the World Wide Web. Included in the national database is 1999 information from sites in Howard, Anne Arundel, Carroll and Prince George’s counties in Maryland.
Amphibians “are out on the front lines of assessing the environment for us,” Droege said, noting that frogs breathe the same air and use the same water as humans, but are often more sensitive to environmental changes.
While there are no hard numbers, Droege said scientists are confident there are fewer frogs in Maryland today than 100 years ago. A certain amount of loss can be inferred right away from the significant loss of freshwater wetlands where frogs live and breed, he said.
Maryland is also one of 45 states where frogs with malformations, such as extra or missing limbs, were found, according to the Web site of the USGS North American Reporting Center for Amphibian Malformations.
“There doesn’t seem to be one smoking gun” causing a decline in the number of frogs, said Dennis B. Fenn, the USGS associate director for biology.
Studies have indicated habitat loss, climate changes, contamination of water, increased ultraviolet radiation, invasive species and disease may each play a role in different areas, Fenn said, so more research is needed.
Donna Carollo and her two sons, Sean, 9, and Russell, 6, are helping with that research. They are three of more than 40 volunteers working for Frogwatch USA through the Howard County Department of Recreation and Parks.
The Carollos have driven to Warfield’s Pond Park in Glenwood after sunset several times this spring to listen to the frogs. They play a tape of frog calls before they go to make sure they can identify local species. When they arrive, they listen quietly for a few minutes and write down which types and how many they think they heard. Later, they will submit the information to the national database.
“I think it’s an important project,” said Carollo, 42, who works part time for the Natural Resources Division of the Howard County Department of Recreation and Parks. “Amphibians are good indicators of the environment, especially water quality.”
“We didn’t realize there were so many types,” said Carollo, who has heard spring peepers, American toads and chorus frogs so far. “It’s fun for us.”
Data from the Frogwatch program, together with more scientific studies by USGS and other organizations, will help target the problems affecting amphibians and highlight potential threats to humans as well, Droege said.
Understanding threats to amphibians is also important because they are an important part of the food chain and because it is the compassionate thing to do, he said.
Citing the current decennial census of the nation’s people Droege said, “that’s the exact kind of thing we need for amphibians.”
Program results and information for volunteers is available at http://www.mp2-pwrc.usgs.gov/FrogWatch/index.htm.