Non-tidal freshwater marshes are located inland. They are the most prevalent and widely distributed wetlands in North America. They are made up of mostly freshwater but some are brackish or alkaline. These marshes are responsible for recharging our ground water supplies and moderating stream flow.
Tidal marshes are those affected by the tide. They are primarily located along the N.E. coast, the gulf coast from Louisiana and Texas, and the Gulf of Mexico. Some are saltwater or brackish (somewhat salty) and all are affected by the tides of the ocean.
Tidal marshes are located in wide expanses of land with generous views and equally generous wildlife. Their location has made them prime development sites infringed upon in the past and presently protected by legislation, both Federal and State wide. The Army Corps of Engineer regulates the use of wetlands. “When your feet are wet, you will be regulated”. The Clean Water Act Sect. 404 controls the usage of waters and wetlands to “restore and maintain chemical, physical and biological integrity.” This jurisdiction is limited by the wetness of the site and applies to wetlands adjacent to waters including marshes. They use soil tests, soil color and plant material to determine qualifying wetlands. Infringement for the building of bridges or other structure involves a type of trade. The quality and impact of the needed area must in fact be “bought” by returning another area to wetlands. Thus the vital influence of wetlands remains stable.
In the year 2005, it was estimated that half of the world’s population lived within 60 km of coastal shoreline. A close partner to the proximity of human population is both water and air pollution.
So what went wrong?
Misunderstandings and Mistakes Made
Marshes were drained in an attempt to reduce the mosquito population. They were filled to provide “ideal” building sites and additional agriculture. They were dredged to provide open waterways.
Draining the marshes killed the killifish which kept the mosquito in check and eliminated a key food source for the birds and amphibians. Filling in the marshes allowed no escape valve for the flooding storm waters which eroded the edges of the land. Dredging the marshes allowed free rein for the rise in the sea level to destroy existing structures.
Marshes were used as waste dumping grounds.
People desperately needed to understand the function of the marsh.
The Miracle of Life within the Marsh
Marshes act as a filter for sediment from upland runoff, estuary and creeks that flow to the bay. By filtering this sediment turbidity and silt accumulation, essential beds are prepared for shellfish and vegetation just as you would prepare a vegetable or flower garden in the spring. Important nitrogen, phosphorus and sulfur are processed rather than being released into the waterways. Pollutants are taken up and used by the marsh plants. |
The nutrient-rich area becomes a nursery for oysters, crabs, clams, striped bass, spot, croaker and menhaden. A rich undisturbed marsh also becomes a hospital or rehabilitation center, allowing injured crabs to grow new claws and storm battered sea creatures to recover. Fish spawn and their young grow in these waters.
Aquatic species of fish, birds, mammals, reptiles and invertebrates live in and depend upon the marsh for food and shelter. Worms, periwinkles, insects, ribbed mussels and tiny crustaceans live in the marsh. Larger animals such as raccoons, otters, beavers, muskrats, birds and reptiles feed upon the smaller ones and make their homes there as well. Flocks of migrating birds count on the rich marshes for shelter and food on their long flights.
The marsh is the most biologically productive habitat on earth rivaling tropical rainforests. Along with providing habitat for aquatic and aviary species, they buffer the water system from humans and the pollution they produce.
It is estimated that 95% of the annual fish harvest is somewhat dependent upon the wetlands. Marshes also temper the water flow during flooding by acting as an overflow basin and buffer storms and water surge.
So What Else Grows There?
Vegetation that grows in marshes exceeds the imagination. Cattails, lily pads and reeds fill non-tidal marshes. Tidal marshes brim over with spartina alternifolia (smooth cord grass) which is the dominant shoreline grass. Spartina patens (black rush), arrow arum, bald cypress, blue flag, Joe-Pye weed, loblolly pine, purple loosestrife, rose mallow, shad bush, seaside goldenrod, sweetbay magnolia, wild rice and salt meadow cordgrass present a wide variety of textures and color. Glasswort (salicornia) can be located in high marsh zones. Phragmities australis, which is invasive, often is seen in degraded marshes in the N.E. United States. There are efforts to eradicate it because it is overwhelming native species.
Making It Better
Our marshes are a continuous part of our shorelines. With the rising of sea level and the increase of recreational use of watercraft, residents are examining the need to preserve shorelines and the marshes. Sometimes this is done by hardening or the use of rip rap or bulkhead to secure the land mass. This creates the unfortunate result of loss of more habitat. Careful planting of masses of native plants upland from the waterfront, rain barrels and rain gardens will help to absorb rain runoff. The roots of the plants help to absorb and slow down the flow of water from the structures on the property as well as holding the bank. Use of natives makes sense as they have adapted to salt, wind and are resistant to animal foraging.
The Virginia Institute of Marine Science’s SEAS program (shoreline erosion advisory service) was developed. This program evaluated shoreline properties and directed homeowners towards educated decisions to prevent erosion and restore waterfront. Now the Master Gardeners of the Northern Neck have developed their own program, the integrated Shoreline Evaluation Assistance (I-SEA). Two to three years were spent in the planning during which time the members became water stewards. The water steward program is an advance master gardener training program through Virginia Tech. This program includes volunteers who will visit homeowners and advise them on preserving the integrity of their shorelines and consequently the marshes. It is operated out of the Virginia Cooperative Extension office in Lancaster County. It serves property owners in Lancaster, Northumberland, Richmond and Westmoreland counties.
We all need to know that what we do impacts the entire waterfront and waterways.
So grab your kayak or canoe and paddle towards a living and growing marsh. Enjoy the mallows in pink and white. Listen to the wind through the grasses and see all that lives there. Stop for ten or fifteen minutes and be still and let it come alive around you.