Salt marshes and tidal creeks provide us with a wealth of benefits, referred to as ecosystem services, including maintaining healthy water, protecting us from flooding and erosion, providing nursery and essential habitat for commercial and recreational fisheries, and supporting recreational activities that have become part of the coastal lifestyle. The system is an attraction for many and offers a unique experience every time you visit it. We need to take actions that reduce risks to the salt marsh-tidal creek ecosystem to make sure people are able to continue enjoying them.
One of the most important benefits the salt marsh-tidal creek ecosystem provides is maintaining healthy water quality. Poor water quality can be a result of excess nutrients, toxins, and/or suspended sediment. A healthy salt marsh has the ability to greatly reduce these pollutants. Excess nutrients and chemicals are filtered out and can be taken up by Spartina plants and stored in their roots and rhizomes as well as broken down by bacteria in sediments. The processing functions of the salt marsh-tidal creek ecosystem help to remove pollutants from the larger estuary.
Sediments in the water are also an important component of the tidal creek-salt marsh system. In general, the estuarine waters of South Carolina, Georgia, and Northeast Florida have higher sediment levels or turbidity than North Carolina and Southeast Florida. The sediment can keep sunlight from penetrating through the water. This is likely why true sea grasses are not found in South Carolina and Georgia but are found in North Carolina and Southeast Florida. Suspended sediments are also important in sustaining the surface elevation of the marsh and in their pollutant processing functions. Pollutants will often adhere to the sediments in water and settle on the marsh surface due to the drag of the plant stems. Some sediment is good to sustain the marsh elevation but too much can limit sunlight penetration and decrease photosynthesis rates.
The tides are also important in controlling the water quality of tidal creeks and salt marshes. In areas with larger tides (South Carolina and Georgia), the constant movement of larger amounts of water in and out twice per day helps to flush the system. In areas with lower tidal ranges and reduced flushing (North Carolina and Florida), eutrophication (excess nutrients) may be an issue and result in fish kills due to the poor oxygen levels. That said, tidal creeks do have naturally low and fluctuating oxygen levels. The low oxygen is thought to keep out the larger predators, making creeks and marshes good nursery habitat for smaller organisms that can withstand lower oxygen levels.
The Southeast has over 1 million acres (405,000 hectares) of salt marsh-tidal creek habitat, all of which play an important role in buffering the coast and minimizing damage from storm surge. The salt marsh-tidal creek ecosystem, particularly vegetation along creek banks and oyster reefs, acts as a barrier that helps to reduce wave energy and current velocity. The natural buffering of the salt marsh helps protect upland areas and private property from flooding and erosion during storms.
Another benefit of the salt marsh-tidal creek ecosystem is the reduction of carbon dioxide (a greenhouse gas). Plants take up carbon dioxide from the atmosphere during photosynthesis, converting the carbon into living and dead plant material. Along the coastline, this is termed “blue carbon”, referring to the carbon captured by coastal plants such as mangroves, sea grasses, and salt marsh grasses and then stored in coastal ecosystem. These coastal plants are reported to sequester 100 times more carbon than forest plants. Since there are thousands of acres of salt marsh in the Southeast, this makes them a significant blue carbon sink. Carbon uptake or sequestration occurs throughout the year but can take different forms. Carbon can be sequestered in the mud, in healthy plants, and in the dead grass as it accumulates as wrack in the winter. This ability makes the salt marsh-tidal creek ecosystem an invaluable habitat for sequestering carbon, reducing greenhouse gases, and ultimately reducing impacts on our climate.
Another one of the primary benefits the salt marsh-tidal creek ecosystem provides citizens is seafood. Seafood consumption is an integral part of Southern culture. Oyster roasts, crab boils, and frogmore stew are frequent staples at parties throughout the Southeast. Along the Southeast coast, our most important fisheries are shrimp, blue crabs, fish, oysters, and clams. The commercial and recreational fishing industries for these animals contribute millions of dollars to the coastal economy and employ thousands of people.
In 2014, the SCDNR reported the commercial seafood industry provided over $23 million to the South Carolina coastal economy. The shrimp fishery alone brought in over $8 million. The salt marsh-tidal creek ecosystem also supports recreational seafood harvesting. Recreational fishing is one of the more popular ways for people to interact with the salt marsh-tidal creek ecosystem. In 2014, the state of North Carolina reported about 304,000 residents purchased recreational fishing licenses, with another 165,000 purchased by non-residents. The value of recreational fishing on each state’s revenue is significant, and a large portion supports efforts for harvesting and conservation. At some point in their life cycle, the salt marsh-tidal creek ecosystem provides essential habitat for over 75% of our important fisheries species.
Without healthy salt marsh-tidal creek habitat, it is unlikely Southeastern fisheries would be as productive and as important to our economy as they are today. We have a responsibility to protect our state’s natural resources, like the salt marsh and tidal creeks, so that they can continue to support both the wildlife and people of the Southeast that rely on them.
Finally, salt marsh-tidal creek habitats provide coastal residents and visitors with many recreational opportunities. Each year, thousands of people spend numerous hours sailing or paddling in our estuaries, admiring the scenic view, and exploring tidal creeks by boat. They spend long afternoons watching dolphins, tracking birds through the sky, hiking along the marsh-upland edge, and hunting water fowl. Artists from all over the world travel to the Southeast coast for the opportunity to paint, draw, and photograph the marsh landscape and wildlife. With its ever-changing nature, the salt marsh is an attraction for many, and offers a unique experience every time one interacts with it.