Study shows streams face murky future By: Kevin Miller, Times Staff Writer September 26, 2000

A three-year study of Maryland's streams had both good and bad news for Carroll County: Fish populations are generally healthy, but aquatic insects and other marine life are struggling to survive in many of the county's nutrient-rich waterways. And while the county is home to one of the healthiest streams in the state, it is also the site of one of Maryland's most stressed freshwater creeks.

Overall, the picture of Maryland's streams was not a positive one. Only 12 percent of the state's freshwater streams were rated as ``healthy'' by state and federal biologists who tested 1,000 randomly selected waterways from 1995 to 1997. In comparison, 46 percent tested ``unhealthy'' and 42 percent were teetering on the edge of unhealthy, according to the study released Monday. In what is being described as the first study of its kind in the country, biologists sampled the streams for the variety of fish and aquatic life species present...., oxygen and nutrient levels,..... as well as habitat for marine life.

State and federal officials plan to repeat the survey in another five years to assess changes. And volunteers are already breaking down the watersheds in Monday's report into smaller sections that will be included in other studies. In the meantime, the report calls on the state to continue directing growth into already established communities and to increase stream buffers. Nearly 90 streams were sampled at least once in Carroll County, which is included in three river basins: the Middle Potomac River basin, which includes much of the western portion of the county and nearly all of Frederick County; the Patapsco River basin, which covers much of the central and southern portion of the county; and the Gunpowder River basin, which includes parts of northeastern Carroll.

Piney Run in South Carroll was ranked among the top 20 healthiest streams in the state, based on the populations of fish and benthos - a term given to the group of invertebrates larger than a pinhead that live in streams. Benthos includes everything from tiny worms to crayfish and mayflies. On the other hand, a tributary to Big Pipe Creek near Taneytown and Detour ranked among the state's top 20 unhealthiest streams, largely because of elevated nutrient levels from farms, according to biologists. Paul F. Kazyak with the Maryland Department of Natural Resources said Carroll County offered conflicting messages: It is home to some of the healthiest streams for fish in the state but some of the unhealthiest for benthos. Kazyak said that is likely because fish are less picky eaters than bottom-dwelling bugs and other marine life, which are less mobile and therefore less able to escape pollution. ``The fish are saying things are OK, but the bugs are telling a different side of the story, so you kind of have to take what the fish are saying with a grain of salt,'' Kazyak said. About 100 fish species live in Maryland streams, with seven classified as rare, threatened or endangered by the state or federal government. The blacknose dace is among the hardiest of Maryland's fish species, living in streams where many other fish could not survive. The brook trout, in comparison, is quickly becoming a rarity in the state. Carroll County is not home to any rare fish species, and its small population of brook trout is dwindling, Kazyak said.

Carroll County streams also measured some of the highest nutrient levels in the state, which may also be a reason for the area's lower benthos populations, Kazyak said. With more than half of its land used for agriculture, the Middle Potomac River basin was singled out in the report as one of the state's two most nutrient-enriched areas. Statewide, 57 percent of the state's streams had unnaturally elevated nutrient levels. Mayflies, stoneflies and caddisflies are highly vulnerable to pollution. One species of the stonefly, which requires a high amount of dissolved oxygen, was found in only nine of the 109 sites sampled in the Middle Potomac River basin.

The report indicated that fertilizer runoff from farm operations and lawns were likely causes of their low numbers. Bank erosion is another major problem both in Carroll and throughout the state. About 80 percent of the stream banks in the Gunpowder River basin were rated as having ``poor'' stability, meaning sediments were likely to erode downstream. The Patapsco basin rated about 70 percent poor, and the Middle Potomac river basin about 60 percent poor. But farms are not the most serious threat to streams, according to Ronald J. Klauda, the DNR's director of monitoring and nontidal assessment division. ``Agriculture is not really the culprit - development is,'' Klauda said. About 16 percent of Maryland's land is classified as urban or suburban. And state officials project that an additional 5 percent of the state's land will become urbanized in the next 25 years. Carroll County's population has grown more than 50 percent in the past two decades, from 97,924 in 1980 to 155,338 this year, according to the most recent estimates provided by the county. Nearly 190,000 people are expected to live in Carroll County by 2020, the county projects. For overall physical health, about 45 percent of the streams in the Middle Potomac basin were rated as being in ``good'' or ``fair'' condition, compared with about 65 percent in both the Patapsco and Gunpowder basins. Statewide, roughly 50 percent of the streams were in good or fair physical condition. Reach Kevin Miller at 410-857-7865 or kmiller@lcniofmd.com.