Above is a picture taken of one of the vast salt marsh habitats around Charleston, SC. These are vastly diverse habitats that grow on the sides of our estuaries here in the Lowcountry of South Carolina. These habitats, being some of the most diverse on the plant, are dominated by one species of plant. This plant is a grass species commonly called Smooth Cordgrass, or Spartina grass. This grass, many will argue, is probably the most important grass here in the Lowcountry (Don’t tell the people in the suburbs who spend tons of time and money keeping their lawns green and healthy with non-native, highly inbred grasses from all over the world). This grass has the scientific name Spartina alterniflora. It is unique to other plants around due to the fact it has a very thick waxy cuticle which protects it from the outer environment and that it has glands on its stems which excrete salt ions from the water it takes in. This gives it the unique ability to grow in the higher salinity water on the sides of our tidal estuary habitats. Due to the lack of competition and vast resources in the marsh habitat, this grass is able to grow in high quantities and take over anywhere they can become established.
So what is the importance of this grass? Well, because it is the only plant growing in this area it is the primary producer of all energy within this habitat. Using photosynthesis it is constantly producing energy which then get transferred to the rest of the ecosystem. All throughout the year, especially during the winter, the stalks of the grass are dying and forming large floating masses called “wrack.” This “wrack” can either end up floating out to sea and being deposited on the barrier island beaches above the high tide line (which plays an important role in dune growth and development along the beaches), or can become waterlogged and sink to the bottom of these estuary habitats. This sinking biomass gets covered in bacteria and fungi which actively decompose the plant material. This bacteria and fungi becomes suspended in the water column, which acts as a food source for a vast number of organisms, especially filter-feeders such as oysters, clams, and other invertebrates. The bacteria and fungi also form a film on the top of the water which gets deposited on the mudflats during low tide and supplies marine worms, fiddler crabs, and other species with food. These organisms are then consumed by other organisms and up the food chain we go.
Along with its energy production, this grass also provides a safe haven for many larval organisms. Fish, shrimp, crab, oysters, and many other organisms depend upon this marsh grass habitat for refuge from predators and for a place where resources are readily available to them. This allows these organisms to grow up in a safe and plentiful environment. Most of the very species which fuel our local seafood economy are dependent upon these salt marsh habitats, and without this grass there is no marsh (since the definition of a marsh is a flooded grassland).
This is of huge importance today. This grass can only grow in a specific tidal area where its roots can be exposed to air half the day and submerged in water the other half. Due to development along our waterways, these habitats are being altered and in many cases this affects the growth of this grass. I hope that we can protect these vast marshes keeping the Spartina alterniflora healthy. If this important grass species goes away, so does the vast ecosystem it supports