In survey, stream dwellers decide what’s healthy
Carrying electrofishing gear on their backs and wearing rubber waders on their feet, Scott Stranko and Tony Prochaska waded into Parkers Creek.
Their aim was to stun and identify every fish, frog and stream dweller in a 75-meter stretch of the stream on Maryland’s Western Shore. Quickly, the two Department of Natural Resources biologists had their first unique find: Prochaska pulled a 4-inch fish from the stream.
“That’s pretty much a record-size eastern mudminnow,” he declared. “They don’t get very big. That’s a wall-hanger for a mudminnow.”
After years of wading into hundreds of Maryland streams, Stranko, Prochaska and other biologists have gotten to know their fish — and streams — well. They are part of the DNR’s Maryland Biological Stream Survey, which for the past few years has examined nearly 1,000 stretches of state waterways to determine the “state of the streams.”
Unlike traditional water monitoring programs, which focus mainly on chemical pollution, the survey rates waterways based on what their inhabitants have to say. It has produced stacks of scientific reports about the state’s 17 major drainage basins, and soon will release a reader-friendly summary, “From the Mountains to the Sea: The State of Maryland’s Freshwater Streams,” detailing their findings.
The fish and other stream dwellers have a lot to complain about: More than half of Maryland’s 9,000 miles of nontidal streams are in bad shape. According to the survey:
- Survey crews judged habitat in 51 percent of the state’s stream miles as being either poor or very poor.
- Populations of insects, clams and other bottom-dwellers — good indicators of a stream’s health — were also in poor or very poor condition in 51 percent of stream miles.
- Fish populations were considered to be good or fair — the top ratings — in just 45 percent of stream miles.
Not all the news was bad: Survey teams found one fish thought to have vanished from the state, the stripeback darter.
But the finding that so many streams are in poor health has surprised many. “A lot of people thought our streams were in better shape than they are,” said Ray Morgan, a professor at the Appalachian Laboratory of the University of Maryland’s Center for Environmental Science, who helped to design the survey.
The conclusions should not be surprising, he and others say. Three centuries of changing land uses have dramatically altered the state’s landscape: Once 95 percent forested, only 80 acres of virgin forest remains.
The remainder of the land has been farmed, logged, paved and bombarded by acid rain. Streams still show the scars. Most have unnaturally high nutrient levels. In fact, the survey concluded that there are no “pristine” streams in the state, although a few dozen high quality waterways are still around.
“We certainly don’t think the health of our streams today is anything like it was before European settlement,” said Ron Klauda, the DNR scientist who oversees the survey. “It almost scares you a little bit to report some of these results.”
Survey results also show development is particularly harmful to streams. No watershed with more than 15 percent “impervious cover” — such as roofs, roads and parking lots — was rated in “good” biological condition. Some creatures are far more sensitive: No brook trout were found in a stream watershed with more than 2 percent imperviousness.
Maryland’s situation is not unique. In the United States, almost all streams could use some rehabilitation. Nearly 20 years ago, the EPA and the U.S. Fish and Wildlife Service concluded that 81 percent of the nation’s fish communities were negatively impacted in some way. Half of the nation’s streams, they said, suffered from habitat degradation.
But Maryland’s survey provides one of the most thorough examinations of stream condition available. James Karr, director of the University of Washington’s Institute for Environmental Studies, a leading national advocate of using biological indicators to measure stream health, called it “one of the best, probably even the best, state level analysis that I have seen.”
The survey’s findings are a sobering preview of what’s ahead for the Bay Program as it “moves upstream.” Its draft Chesapeake 2000 Bay Agreement, expected to be signed this summer, has several commitments aimed at protecting and restoring stream corridors.
The agreement envisions restoring not only the Bay, but pledges to help migratory fish by ensuring that “suitable water quality conditions exist in the upstream spawning habitats upon which they depend.” The Maryland survey suggests that job will be enormous.
Traditional water quality monitoring programs are based mainly on measuring the amount of chemicals in a stream. But chemical testing alone is only part of the story. Fish and water-dwelling insects may react less to individual chemicals than to the whole range of pollutants and other stresses — such as degradation and loss of physical habitat.
“We often don’t see single chemical impacts,” Morgan said. “It is a multitude of chemicals in some places. The biotic community is the best thing to look at because that’s the integrator of the watershed. It tells you what is going on in the watershed above that sampling point.”
To get that picture for streams across the state, a computer randomly selected hundreds of stream sites to be surveyed by Prochaska, Stranko and others.
With lists of stream sites in in their pockets, the biologists — electrofishing equipment strapped on their backs and global positioning systems in their hands — tracked down owners for each site, secured permission to examine the stream (88 percent said yes) and proceeded to study a 75-meter stretch of water.
On some days, survey teams worked in clear mountain streams. Other days, the computer sent them wading through overgrown Coastal Plain streams, where they sometimes hacked their way through overhanging briars with machetes in 95 degree heat and 100 percent humidity.
On still other days, they would stand in the midst of an urban stream with broken sewer lines discharging straight into the water, or — perhaps even worse — pipes spewing unidentifiable orange goo. One fenced-in stream outside Washington was particularly disgusting: “Homeless people were going to the bathroom in bags and throwing it over the fence,” Stranko said.
On those days, crews added rubber gloves to their list of gear.
Once in the water, their electrofishing equipment allowed them to stun, identify and examine every fish, amphibian or reptile in the stream.
Standing in Parkers Creek, Stranko and Prochaska not only found the record-size eastern mudminnow — the most common fish in Coastal Plain creeks — but also American eels, a brown bullhead catfish, golden shiner, redfin pickerel, pumpkinseed, least brook lamprey and creek chubsucker. “Not bad at all,” Stranko declared of the eight-species catch. In addition, they netted a bullfrog and pickerel frog.
Then, donning sunglasses to mute the glare, they turned their eyes to the benthic macroinvertebrates — insects, clams and other stream-bottom dwellers (often called “benthos”). They skimmed the water and sediment with a net, then pored through the catch like kids examining a trick-or-treat bag.
They found nothing remarkable, although the contents included some hellgrammite larvae, an immature dobsonfly which can indicate a relatively healthy stream. Most of the benthos were packed off to a lab for further identification.
They surveyed the ground for five meters on either side of the stream for reptiles and amphibians and found none.
Then they turned their eyes to the stream itself: Its banks showed some signs of erosion, though not too serious. The bottom of the stream still had a good amount of exposed rocks and other solid surfaces, which are important habitat features. The streamflow was slow — in part because conditions had been dry, and in part because Parkers Creek is on the relatively flat Coastal Plain.
“Coastal Plain streams get a bad rap because they’re turbid and stagnant looking,” Stranko said. “They’re not as impressive as a fast-flowing mountain stream.”
Finally, their work done, they packed their equipment and their samples of benthos and stream water for later analysis. Then it was off to the next site.
That process was repeated nearly 1,000 times from 1995-97. The large number of randomly selected sites allows scientists to estimate with confidence the condition of the state’s roughly 9,000 miles of nontidal streams.
In fact, they can even estimate the numbers of fish in those streams. By the survey’s estimates, the state has more than 60 million fish in its wadeable nontidal streams, of which about 1 million are game fish (but only about 119,000 are of catchable size).
What is more important than their numbers, though, is what those fish are saying. The survey largely determines the state of a stream by the state of its residents — fish and benthos. To determine that, scientists use an “index of biological integrity” — or IBI. An IBI weighs numerous factors, such as the number of species in a stream, and the abundance of each species, to help gauge the stream’s condition.
For instance, a stream with a high IBI score would not only have a lot of fish, but many different species as well. A stream with a low IBI may still have lots of fish, but they might all be from a couple of pollution-tolerant species. Similarly, IBIs were developed to measure the health of benthic communities.
With the IBI, Klauda said, “the biotic community tells us how they feel. But they don’t always tell us why they don’t feel well.” That still requires some detective work.
Playing detective means drawing on information about physical habitat and water quality information collected at the streams. In addition, scientists compare results with land use information upstream from each survey site.
Putting it all together, the scientists found nutrient levels several times higher than the statewide average in streams where farmland accounted for more than half the watershed. They found that habitat quality improved as forest buffers got wider. And they found a stark decline in species, and habitat quality, associated with development — the biological health of streams with more than 50 percent urban development in the watershed was always poor.
But not all of the answers are in. Some IBIs need refinement. No IBI was developed for naturally acidic “blackwater” streams on the Eastern Shore. Also, high-quality coldwater trout streams are naturally less productive than warmwater streams and may need a separate IBI.
Nor has all the information been reaped from the mountains of data generated by the survey. While several scientific papers have already been published, more are planned as scientists work their way through the information.
Morgan, for instance, is analyzing survey results about fish anomalies — such as parasitic infections, lesions or tumors. Normally, information about anomalies is collected only near discharge points, not statewide. The survey data will help him learn what other factors may contribute to such problems. “We found anomalies in some watersheds — low numbers — but it is important as a baseline for future work,” he said.
Even as scientists continue sorting through information from the first statewide survey, a second round is set to begin this year. Through 2004, crews will examine more than 1,500 sites — some revisited from the first round, but mostly new ones. The survey will also add tidal streams to its sampling.
The new round of sampling will help scientists begin answering the key question of whether waterways are getting better or worse.
Beyond that, the survey is expanding to include volunteer monitors. Teams of three to five people will take benthos samples at about 20 sites. Asking each team to do so many sites is “pretty ambitious,” acknowledges Dan Boward, a DNR biologist coordinating the effort, but it will cover an additional 1,000 sites per year in smaller watersheds. The response has been enthusiastic: Nearly 200 people were trained at monitoring workshops.
To build more public interest, the DNR plans to widely distribute a first-of-its-kind “State of Maryland Streams” report set for publication this summer. It also plans to make watershed-specific information from the survey available on the internet, so people can easily find out about their local watershed.
Public outreach is important, survey scientists say, because of the tough decisions about Maryland streams that lay ahead. While information from the survey will help to identify where restoration efforts should be focused — for example, where forest buffer restoration could link areas of good habitat — it also raises difficult questions.
With more than half of the streams in bad shape, the survey reveals a daunting task ahead when it comes to stream restoration. It’s a potentially costly task — restoration of urban streams can easily cost $1 million a mile.
That raises serious questions, scientists acknowledge: Is limited restoration money best spent on costly efforts to restore highly degraded urban waterways, or is there more “bang for the buck” in restoring a greater amount of less-degraded habitat elsewhere?
And, despite the emphasis on “smart growth,” the survey results raise questions of whether any growth is smart in some areas if sensitive species such as brook trout are to be maintained at viable levels. “What I’m afraid of is that development is going to overwhelm some systems so much that we’ll not be able to restore them properly,” Morgan said.
Ultimately, those decisions will affect more than just local waterways; they will trickle down to the Chesapeake as well. The Bay and the rivers and streams that feed it are shared by many of the same inhabitants. Decisions made about those waterways, not just in Maryland, but throughout the Bay’s 64,000-square-mile watershed, will ultimately affect the fate of the Chesapeake.
“I don’t see,” said Klauda, “how the Bay can be any healthier than the streams that are feeding into it.”
For information about the MBSS, or to view its reports, visit the survey’s internet site: www.dnr.state.md.us/streams or call Ann Smith at 410-260-8611 or DNR toll-free at: 1-877-620-8DNR Ext. 8611
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