Nanticoke River Grass Watchers and Submerged Aquatic Vegetation

What Are River Grasses or Submerged Aquatic Vegetation (SAV)?

Submerged aquatic vegetation (SAV) are river grasses that grow in shallow tidal and nontidal waters. River grasses grow in salt, brackish, and freshwater waterways. Like terrestrial grasses, aquatic plants have leaves, seeds, roots, and stems. But they differ from land plants in that they have unique properties that allow them to thrive in waterways.

The Nanticoke RiverGrassWatchers Volunteer Program

The Nanticoke Watershed Alliance will be giving you the opportunity to help us find river grasses in our creeks and on the river! The River Grass Watchers Program will be a part of the Chesapeake Bay SAV Watchers Program and follow that program’s protocol. The key goals of the program are to identify locations and types of river grasses present and to also identify locations for river grass restoration, so surveys and the data you collect are important whether grass is present or not.

Unlike the Nanticoke Creekwatchers Program, River Grass Watching can be done on your own schedule, as often as you’d like, and with limited equipment. It’s especially suited for kayakers and other boaters, although foot-accessible streams can also be surveyed for those without a boat. In May-June 2020, NWA will host a couple of workshops for prospective volunteers. You’ll learn more about river grasses, why they’re important, and how to survey for them. Workshops will also give you the opportunity to participate in a field survey. In addition, trained volunteers will be able to check out kits from the NWA.

Contact Beth Wasden for more information about this program and watch this page for information about workshops.

Water starwort (Callitriche spp.) is a bay grass that is common throughout the fresh waters of the Chesapeake Bay. It can be identified by its bright green, egg-shaped leaves that float on the surface of the water.

Wild Celery (Vallisneria americana)

Wild Celery (Vallisneria americana), is another common bay grass that grows in fresh and slightly brackish environments throughout the Chesapeake. It can be identified by its long, ribbon-like leaves.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Why are River Grasses Important?

  • These plants provide food and habitat for a number of critters, including waterfowl, fish, shellfish, and invertebrates. The seeds, tubers, and leafy vegetation of the plants are an important food source. Additionally, river grasses provide nursery sites and shelter for many aquatic critters.
  • Grasses generate oxygen through photosynthesis. Photosynthesis is the process in which plants convert carbon dioxide (CO2) from the atmosphere into sugars they use for energy. Just as we need oxygen, it’s also essential for aquatic critters!
  • Shorelines can take a beating from high-energy waves, and river grasses slow down wave action. Healthy grass beds are dense and help reduce water currents. Also, the plant roots hold river and creek bottoms in place.
  • Grasses filter and trap sediment from the water that would otherwise bury critters on the bottom and make water murky.
  • Grasses absorb excess nutrients from the water. The Nanticoke River and its creeks have very high nitrogen throughout. As plants grow, they uptake nutrients such as nitrogen and phosphorus, which reduces algal blooms and improves water clarity.

 

 

What are the Current Threats to River Grasses?

  • The use of agricultural and lawn herbicides may cause a loss in some SAV species. Industrial pollutants and foraging animals can selectively kill off local beds. Invasive species can cause significant damage to river grass populations by feeding directly on the grasses’ vegetative and reproductive structures.
  • River grasses need a certain amount of nitrogen and phosphorus to thrive, but high levels can hurt SAVs. Excessive levels of nitrogen and phosphorus cause algal blooms, which cloud the water, significantly reducing the amount of sunlight available to grasses. Runoff can also cloud water over many acres of SAV beds with sediment and reduce water clarity.
  • Rising temperatures associated with climate change could make the habitats of certain SAV species unsuitable. Flooding and shoreline erosion input sediment into the water, also leading to decreased water clarity.

Sources and Additional Information: