Sediment processes and mangrove-habitat expansion on a rapidly-prograding Muddy Coast, New Zealand
Mangrove-habitat expansion has occurred rapidly over the last 50 years in the 800 km2 Firth-of-Thames estuary (New Zealand). Mangrove forest now extends 1-km seaward of the 1952 shoreline. The geomorphic development of this muddy coast was reconstructed using dated cores (210Pb, 137Cs,7Be), historical-aerial photographs and field observations to explore the interaction between sediment processes and mangrove ecology. Catchment deforestation (1850s-1920s) delivered millions of m 3 of mud to the Firth, with the intertidal flats accreting at 20 mm yr-1 before mangrove colonization began (mid-1950s) and sedimentation rates increased to ≤ 100 mm yr-1. 210Pb data show that the mangrove forest is a major long-term sink for mud. Seedling recruitment on the mudflat is controlled by wave-driven erosion. Mangrove-habitat expansion has occurred episodically and likely coincides with calm weather. The fate of this mangrove ecosystem will depend on vertical accretion at a rate equal to or exceeding sea level rise.
Publication Source (Journal or Book title)
Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes
Swales, A., Bentley, S., Lovelock, C., & Bell, R. (2007). Sediment processes and mangrove-habitat expansion on a rapidly-prograding Muddy Coast, New Zealand. Coastal Sediments '07 - Proceedings of 6th International Symposium on Coastal Engineering and Science of Coastal Sediment Processes https://doi.org/10.1061/40926(239)111