Submerged Aquatic Vegetation, The River’s Health Barometer

By: Audrey Pleva


Wild Celery underwater in the Susquehanna River. Credit: Debbie Hinkle, Chesapeake Quarterly

AWS is now moving underwater and beginning an exciting effort to restore the river’s submerged aquatic vegetation (SAV).  These beautiful grasses are essential to cleaning the river and providing oxygen to our suffocating fish and other aquatic organisms.

The Anacostia River has been void of SAV for many years due to the high turbidity (murky water) of the water.  Sediment washed down by stormwater runoff brings tons of particles to be suspended in the water column, blocking sunlight to the river’s floor.  Without these plants, there is nothing to filter the sediment from the water column, leaving the river looking cloudy and dirty. Also, with no cover from predators, small fish species and young fish have no place to make their home, affecting their populations. This not only affects the food chain in the aquatic ecosystem of the river, but also fishing as an important recreational/economic activity in the river.

If you spend enough time outdoors near the water, you probably have witnessed fish kills in the river and its tributaries. In the summer, these fish kills are often caused by low dissolved oxygen levels in the water. This is often related with low or no rainfall which causes less oxygen-rich stream flow input from the main tributaries into the tidal Anacostia. These grasses will help provide the much needed dissolved oxygen and perfect habitat for fish and wildlife.  

Due to the tireless efforts of AWS and our many partners, the water quality of the river has seen its first rise upwards this past couple of years. Even though water clarity has remained static other water quality variables are trending towards improvement such as dissolved oxygen, fecal bacteria, and chlorophyll --a measure of microalgae biomass which can impact water clarity and dissolved oxygen levels. This makes it a good scenario for SAV propagation in the Anacostia River!

A bed of SAV emerged naturally in Washington Channel near the mouth of the Anacostia to the Potomac River late in 2013.  The presence of this SAV bed is what drove the efforts to plant more SAV while the river seems able to sustain life.  These wonderful underwater plants can really help improve water clarity. The average depth of visibility in the Anacostia River is about 3-6 inches, in the heart of this SAV bed in the Washington Channel, the visibility depth is about 6 feet!


Photo of Mattawoman Creek in Indian Head, MD near where Wild Celery was collected.  Credit: AWS

AWS has begun collections of one SAV species, Vallisneria americana (Wild Celery) out of Mattawoman Creek in Indian Head, MD.  This beautiful watershed has been a model ecosystem that we believe the Anacostia River could become.

The plants taken from Mattawoman Creek will be planted at Buzzard Point, Kingman Marsh, and Kenilworth Marsh.  Our hopes are to increase the coverage of SAV and slowly increase the visibility and oxygen saturation of the River. Plantings will occur over the next 3 weeks and will be protected by PVC cages with orange snow fencing to keep out any waterfowl (yes, I’m talking to you Resident Canada Geese!). After a few months of allowing the plants to take root, we will check to see how many of these plants successfully went to seed in late August. 

We will also be testing water clarity and dissolved oxygen before and after the plantings to determine the success rate of the plantings. If the project is successful we will be on to something really exciting for the river, by expanding the acreage of SAV beds in the river we could reach an important milestone in making the Anacostia River fishable and swimmable.  


Handful of Wild Celery collected from Mattawoman Creek. Credit: AWS
 

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