Highlights
In 2002, a year of severe drought, DNR's Monitoring and Non-Tidal Assessment Division completed the third year of the five year Round Two of the statewide Maryland Biological Stream
Survey (MBSS).
- Eighty-nine percent of all landowners who responded to phone or letter permission requests allowed MBSS field crews to sample streams on their properties.
- A total of 219 non-tidal stream sites in 32 of Maryland's 138 watersheds were sampled in 2002.
- Combining 2000 through 2002 data, 14% of all stream miles, statewide, were rated in Good condition, 41% were rated Fair, 28% were rated Poor, and 17% were rated Very Poor based on
fish and benthic macroinvertebrate indicator scores.
- Biological community indicator scores tended to be lowest in lower Eastern Shore streams; but Willett Branch in the Potomac River Montgomery County watershed, central Maryland, had
the lowest biological score.
- Four state-listed rare fish species were collected in 2002: mud sunfish,
 banded
sunfish, pearl dace, and swamp darter; two uncommon fish species, warmouth and rainbow darter, were also collected.
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Combining 2000 through 2002 data, 38% of all streams, statewide, were rated in Good condition, 24% were rated Fair, 21% were rated Poor, and 10% were rated Very Poor based on physical habitat scores; habitat in 7% of all stream miles could
not be rated.
- In 2002, one stream habitat problem, channelization, was most prevalent in the Nanticoke River watershed (80% of all stream miles) and in the Lower Pocomoke River watershed (70% of
all stream miles).
- Other physical habitat problems documented by the MBSS in Maryland streams during 2002 were severe bank erosion, non-vegetated riparian areas, dominance of non-native invasive
plants in these areas, and low amounts of woody debris and root wads.
- Chemistry measurements taken in 2002 showed that about 20% of all stream miles were either acidic or sensitive to acid inputs from atmospheric deposition, mining, agricultural
fertilizers, and leaf tannins---mostly in watersheds on the lower Eastern Shore, southern Maryland, and far western Maryland.
- Stream concentrations of two nutrients, nitrogen and phosphorous, were highest in Eastern Shore streams, where total nitrogen concentrations at baseflow conditions exceeded 10 mg/L
in four watersheds.
- Despite the fact that 2002 was a severe drought year, biological indicator scores at 27 sentinel (high quality) stream sites were not consistently low; only two Coastal Plain
sentinel sites went dry during the summer.
- No changes were detected in biological community or physical habitat scores for streams in three watersheds sampled in 2002 that were also sampled during the Round One MBSS,
1995-1997.
- Information from the results of stream sampling in 2002, plus data collected in 2000, 2001, and the rest of Round Two (2003 and 2004) will be used to support a wide array of
management decisions by DNR and other agencies; e.g., 2000 Chesapeake Bay Agreement, 305(b) report, and Clean Water Action Plan.
The full document is available here as a 12.2 MB Acrobat PDF file.
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