Wetlands are the transitional area or the link between land and water where water covers the soil periodically or throughout the year. The presence of water, nutrients, and sunlight makes wetlands a unique ecosystem in the watershed. The Raritan region includes both inland and coastal wetlands. Examples of coastal wetlands include tidal marshes and mudflats while inland wetlands include swamps, marshes, bogs, depressions, and overflow wetlands along rivers and streams. Wetlands provide a myriad of benefits and services including water filtration, shoreline stabilization, floodwater storage, groundwater recharge, and habitat for fish and wildlife. Most relevant to water quality are wetlands’ services for water filtration and stormwater management where wetlands capture and filter materials, sediment and waste from stormwater runoff and floods. Even though wetlands provide a wide range of benefits to society, wetlands loss continues to be prevalent due to infrastructure development, land conversion, water withdrawal, pollution, over-exploitation, and introduction of invasive alien species. An assessment of conversion of wetlands is, therefore, important to understanding water quality in the watershed.
Overall, Raritan wetlands continue to decline in acreage with a loss of over 14,500 acres or more than 13% decline in wetlands since 1986. Decline in wetland acres has a negative impact on water quality.