About the Maryland Biological Stream Survey

Stream sampling

The Maryland Biological Stream Survey’s (MBSS) goal is to provide the best possible information for ensuring the protection and restoration of Maryland’s stream resources.

The MBSS was created in 1993 by the Maryland Department of Natural Resources (DNR) as a way to characterize the health of Maryland’s 10,000+ miles of freshwater streams. Sites are selected using a rigorous statistical design that allows DNR to estimate stream condition in medium and large watersheds, as well as statewide. Data is collected at each site on the physical, chemical, and biological (fish and insects) characteristics, and then combined into an overall assessment. Since 1995, the MBSS has surveyed 3,405 sites across Maryland. For more details on the program, please visit the MBSS website.

The MBSS program has striven to not only collect high-quality data, but make its findings and results available to the scientific and lay audiences. This website is intended to help in that effort. You can also download MBSS publications at the Publications portion of the website. Data can be accessed on the MBSS Searchable Database.

Learn more about helping the Maryland Biological Stream Survey with their efforts.

Office of Governor

Message From the Governor

The health of the Bay is ultimately determined by what we do on the land -- in our cities and towns, on our farms and forests, in our schools and backyards. The 10,000 miles of streams that run through our communities can deliver either clean water or pollutants to the Bay. It’s our Bay and it’s our choice.

Thank you for choosing to get involved in improving the health of your stream and our Bay.