Salt Marsh – coastal wetlands that are flooded and drained by salt water brought in by the tide.
Sediment – matter that settles at the bottom of the water, such as decomposed plant matter.
Sediment Deposition – the laying down of sediment that has been suspended in the water.
Sediment Accretion –the accumulation of deposited sediment causing the vertical growth of the marsh.
Four Major things that make the salt marsh useful to people:
1- Acts like a filter – acts like a gigantic sponge and absorbs the tide water coming in; collects sediments, toxins, and nutrients.
2- Acts as a grocery store –is a critical part of the food chain– salt marshes create more new biomass than a rain forest each year.
3- Acts as a nursery – includes everything (food, water and shelter) that baby birds, fish, insects need to survive.
4- Acts as a barrier – gets larger as it absorbs water – 1 mile of marsh absorbs about one foot of storm surge; a marsh also absorbs the energy of waves.
The deposition of new growth on the marsh is faster than decomposition so that salt marshes get thicker over time. Salt marshes grow about 1 foot every hundred years. The Hammonasset salt marsh developed after the glacier left and is about 1500 years old.
The salt marsh is composed of deep mud and peat and is very spongy – it bounces when you jump on it.