Recent Streams News

New Report on Acidity in Maryland Streams

The 1990 Amendments to the federal Clean Air Act and other air quality regulations have reduced the deposition of sulfur and nitrogen oxides, the precursors of acidic precipitation (acid rain), in Maryland. In 2012, DNR repeated a 1987 stream chemistry survey, 25 years later, in two regions of the State: Appalachian and Southern Coastal Plain. The purpose of the 2012 survey was to answer this question: Have Maryland streams responded to reduced deposition of sulfur and nitrogen compounds? For findings of the 2012 survey, go to this link.

Recent study finds macroinvertebrates sensitive to nutrients in Maryland’s headwater streams.

Excessive nutrient concentrations in streams flow into tidal rivers and estuaries, which affects the health of Chesapeake Bay. Millions of dollars have been spent to intercept and reduce nutrients on the land and in streams, but little is known about how these conditions might influence stream health. A recent study of Maryland Biological Stream Survey data published in the scientific journal Environmental Monitoring and Assessment found a handful of macroinvertebrate taxa were indicative of a streams nutrient concentration. Other key conclusions were that 1) additional factors, like stream habitat or chemistry, did not affect these sensitive organisms as much as nutrients and 2) the index of biological integrity, a common measure of stream health, was not strongly related to nutrients, as were other regularly used measures.

Ashton, M.J., R.P. Morgan, and S.A. Stranko. Relations between macroinvertebrates, nutrients, and water quality criteria in wadeable streams of Maryland, USA. Environmental Monitoring and Assessment DOI: 10.1007/s10661-013-3447-1

Follow this link to view the document online.

The Effects of Hurricanes and Tropical Storms on Stormwater Runoff and Maryland’s Streams

During the summer of 2011, Hurricane Irene and Tropical Storm Lee combined to drop a large amount of rain on Maryland. Stormwater runoff is a natural occurence, but its effects can be worsened by urbanization and an increase in impervious surfaces. The Maryland Biolgical Stream Survey made extra trips to see if there were any adverse reprecussions from this influx of heavy rains.

Check out this short fact sheet on stormwater, runoff, and its affects on Maryland streams.

The MBSS and Hydro-ecological Assessment

The Department of Natural Resources’ Monitoring and Non-Tidal Assessment Division is one of several agencies (Maryland Department of the Environment, Maryland Geological Survey, and U.S. Geological Survey) participating in a study of ground and surface waters in the Fractured-Rock area of Maryland. This study is being conducted because watersheds in the Fractured-Rock area are showing signs of having limited availability to providing water for human consumption without causing adverse impact to streams.

To learn more about research on flow changes due to droughts, go here.

For more information, check out this fact sheet

Monitoring Fish Passage on the Patapsco River

The Maryland Biological Stream Survey (MBSS), in collaboration with American Rivers, NOAA, and the Maryland Fisheries Service, is performing biological monitoring in the Lower North Branch Patapsco River as part of the removal of Simkins and Union Dams. The goals of this project are to determine the potential impacts of dam removal on American eel (Anguilla rostrata) distribution as well as fish, benthic macroinvertebrate, and fre​shwater mussel communities of the Patapsco River.

Learn more in this fact sheet.


Gear Cleaning, Does it Make a Difference?

That is a question that many people ask when they learn that they are being asked to carefully clean their gear after each use. After all, many people reason, ‘I really don’t do anything that makes me especially different and, I am in a hurry to get home after fishing and after all, I really don’t see why cleaning is so important’. The truth is that any one of us could be the one to transport a devastating new species to our favorite water. Proof that we need to clean is well documented and cleaning is something we all should do every time.

Things to Remember

  • Anglers and water monitors pick up mud on their boots
  • Mud can carry invasive species
  • Anglers and water monitors are highly mobile
  • Felt-soled boots are known vectors for invasive species
  • Don’t use felt-soled boots
  • Inspect, Clean & Dry should be a routine practice for anglers and water monitors

Learn more in this .pdf file

MBSS Crew Finds Zebra Mussels During Maryland Darter Search

During the week of July 5-9, 2010, while searching for Maryland darters in the Susquehanna River below Conowingo Dam, a MBSS crew led by Jay Kilian and Matt Ashton collected 11 suspicious-looking freshwater mussels that were confirmed to be zebra mussels (Dreissena polymorpha)----see photo.. We now know that a population of this non-native, invasive mussel is established in this portion of the Susquehanna. Although their density is currently low, the 11 zebra mussels were large, ranging in shell length from 23 to 38 mm, and probably 3-4 years old. MD DNR is urging boaters, anglers, and other recreational water users who enjoy the lower Susquehanna River to help stop the spread of harmful zebra mussels to other Maryland waters.

The Blackbanded Sunfish: Protecting One of the Rarest Fishes in Maryland

Once known from swampy streams and millponds within the Delaware, Choptank, Nanticoke, Wicomico, and Pocomoke river basins on the Delmarva Peninsula, the Blackbanded Sunfish has declined over the past 50 years and is now exceedingly rare in Maryland and Delaware.In response to the regional decline of this species, biologists from the Maryland Department of Natural Resources MDNR) Maryland Biological Stream Survey, MDNR Fisheries Service, Natural Heritage Program, Frostburg State University, and the Delaware Division of Fish and Wildlife initiated an interstate conservation action strategy in January 2008. The goal of the strategy is to protect Blackbanded Sunfish in Maryland and Delaware by developing and implementing specific conservation actions necessary to protect all populations.

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The Invasion of the Rusty Crayfish in Maryland

The invasive Rusty Crayfish was discovered by biologists of the Maryland Department of Natural Resources (MDNR) in Marsh Creek, a northern tributary to the Monocacy River, in 2007.This crayfish, a formidable invader and nuisance species that has caused ecological damage in many other regions (, is believed to have been introduced into the Monocacy River as bait by anglers. It is now highly abundant and reproducing in the northern portion of the river. Since any attempt to eradicate this species would cause undue harm to other aquatic species and would likely prove futile, MDNR focused its efforts on preventing the spread of Rusty Crayfish by anglers from the Monocacy into other Maryland watersheds.

Continue this story.

Maryland Darter Survey

MD Darter

The Maryland Darter is the only fish species endemic to Maryland, meaning it is found only in this state. It was last seen several years ago in Deer Creek near to the Susquehanna River. State biologists are concerned that changes in land use have caused the extirpation of this unique bottom-dwelling fish. DNR is conducting surveys in conjunction with Frostburg State and Marshall University to see if there is a population still inhabiting the area.

For more information, see our 2011 and 2012 reports.