Yellow Lance Mussel in Montgomery County!

May 23, 2019
  |   1 Comment

Yellow lance mussel (Elliptio lanceolate)

In 2015, Montgomery County Department of Environmental Protection (DEP) Biological Monitoring team found a yellow lance mussel (Elliptio lanceolate) while conducting a fish survey on the Hawlings River. The yellow lance mussel is a freshwater mussel that is sensitive to water quality and can be found in clean, moderate flowing streams. Their population have declined over the years due to pollution. The yellow lance mussel was formally listed as federally threatened under the Endangered Species Act by the U.S. Fish and Wildlife Service (USFWS) in April 2018.  Currently, the mussel can be found in the Patuxent, Rappahannock, York, James, Chowan, Tar, and Neuse River basins in Maryland, Virginia, and North Carolina.

Why are mussels important? Mussels improve water quality by filtering small particles from the water as they eat.

About the Patuxent River Watershed

Graphic: Map of the Patuxent watershed and its subwatersheds in Montgomery County.

The Patuxent River watershed spans 908 square mile beginning in Frederick County and then flows through seven other counties: Howard, Montgomery, Prince George’s, Anne Arundel, Charles, Calvert, and St. Mary’s Counties.

In Montgomery County

In Montgomery County, the Patuxent River watershed has three subwatersheds:

  • Upper Patuxent (Triadelphia Reservoir)
  • Lower Patuxent and
  • Hawlings River (Rocky Gorge Reservoir

The total drainage area of these subwatersheds is approximately 61 square miles – about seven percent of the total Patuxent River basin and about eleven percent of the County’s total land area.

Hawlings River – a Tributary to the Patuxent River

Photo: Hawlings River

The Hawlings River subwatershed has the most urban/suburban uses, including drainage from Olney and Brookville and contains two tributaries: Reddy Branch and James Creek. The headwaters of the Hawlings River are mostly agricultural lands with the middle section protected by the Rachel Carson Conservation Park. There is also significant drainage from the closed Oaks Landfill.

Since 1996, there has been a local, inter jurisdictional agreement to protect the resources of the reservoirs, tributaries, and contributing drainage. Helping to protect creatures like the Yellow Lance mussel.

Protecting the Patuxent River Watershed in Montgomery County

Photo: Bioretention by the school parking lot (2018)

Watershed restoration is a set of tools the County uses to fight against stormwater pollution to help keep our waters clean.

These tools include capturing stormwater runoff as well as physically enhancing stream conditions by constructing aquatic habitat or planting native vegetation including trees.

Rosa Parks Middle School

In 2016, the Montgomery County DEP in partnership with Montgomery County Public School installed six practices to manage stormwater runoff from the school parking lots.

Reforestation at the Oaks Landfill

Since 2011, Montgomery County DEP has planted over 45 acres at the Oaks Landfill, including six acres planted in 2018 with grant funding from Maryland Department of Natural Resources.

Photo: DEP staff at the Oaks Landfill tree planting in 2018


Photo: Trees planted at the Oaks Landfill in 2018

Healthy Watershed for all! 

Maryland-National Capital Park and Planning Commission has acquired many properties over the years to protect and conserve the waters in the Hawlings River watershed. The Rachel Carson Conservation Park conserves 650 acres in the watershed with more than six miles of natural surface trails.

To visit parks in the Patuxent River Watershed, learn more:

Protecting and conserving green areas is not only good for water quality for sensitive creatures such as the yellow lance mussel, but for all of us by providing green areas for all to enjoy!

One comment on "Yellow Lance Mussel in Montgomery County!"

  1. sandy spencer says:

    We are conducting searches for yellow lance mussel on the Patuxent Research Refuge, the Patuxent River runs through our property. Can you tell me about where the yellow lance was found? I realize you cannot give exact location, but perhaps ballpark area. I’m trying to measure the distance from the refuge. I am a US Fish and Wildlife Service biologist, your info is safe with me! Thanks!

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