Results

One of the many results of the MBSS has been a better understanding of the fresh-water stream fauna. We have greatly expanded the information on both native and invasive aquatic species.

Collectively, Rare, Threatened and Endangered (RTE) species tend to be found only in places with very low levels of impervious land cover. And the distribution of all Maryland imperiled aquatic species has declined over the last 30 years. It is these rare species that define an area such as a state, watershed, or county ecologically and make it unique - different from other areas. Examples are dwarf wedgemussels in the Corsica watershed; tiger salamanders only found in Millington; the Marshyhope creek watershed is the only place in the entire Chesapeake Bay watershed with known extant blackbanded sunfish populations. The federally threatened bog turtle actually tends to do very well in wetlands often associated with pastures, but is not found in areas with much impervious land cover.

While native (and endemic) species are being lost, non-native species are increasing in Maryland. There has been much recent research relating the success of non-natives to disturbed habitats, especially in urban and urbanizing areas. This process of losing native and gaining non-native, species is called biological homogenization. In an article in Science in 2000 Frank Rahel showed that the fish assemblages in US states are, on average, 7% more similar now that they were before human intervention, due to extinctions and introductions. Maryland watersheds are also much more similar today than they were as little as 30 years ago because of introductions and extinctions that are facilitated by habitat homogenization through urbanization.

KEY ACCOMPLISHMENTS

• Published first ever State of Maryland's Streams (6MB pdf) report
• Started a volunteer component of the MBSS called Stream Waders that has sampled over 3,500 streams across the State
• Integrated MBSS data into MDE's 303(d) listing, TMDL program, and antidegradation policy
• Identified imperviousness (209 KB pdf) as a major stressor and "stronghold" watersheds (193 KB pdf) for native species
• Shared MBSS data with other DNR units; many federal, state, and local government agencies; university researchers; students; consultants; and the public (see side bar for links to searchable and downloadable data)

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This page was updated on 7/17/2008