Coastal wetlands play an important role as natural connections between oceanic and terrestrial ecosystems. Not only coastal wetlands are important sink of carbon, they also act as natural filters to remove excess terrigenous nutrients from the ocean. Coastal wetlands include the following habitats: seagrass meadows, rivers, tidal creeks, estuarine, tidal flats, coral reefs, continental shelf waters and bottoms. With a high environmental heterogeneity of physical and biological parameters across, such as grain size, salinity and vegetation type and coverage, a coastal wetland is usually observed to be constructed with more than one habitat. Such microhabitats may present different biogeochemical and ecological features than each other. However, due to the complexity to collect samples and get a comprehensive picture of this heterogeneity, it is often overlooked as most studies focus on larger regional or even global scale. Our project will investigate the nitrogen removal ability of selected microhabitats in a coastal wetland including mangrove forests, mudflats, seagrass beds and oyster reefs. Slurry and intact core incubations will be set up to quantify nitrogen removal rates of microhabitats sediment. Understanding nitrogen cycles in microhabitats could allow a more precise detection of cycling hotspots in the coastal wetlands and identification of crucial overlooked pathway and interaction between the nitrogen, sulfur and carbon cycles. Such knowledge may also give insights to future natural based solution development.

 

DNRA, denitrification, anammox, seagrass, mangrove