TY - JOUR TI - Nutrient fluxes from sediments pose management challenges for the Knysna Estuary, South Africa AU - Human, LRD AU - Weitz, R AU - Allanson, BR AU - Adams, JB T2 - African Journal of Aquatic Science AB - This study investigated seasonal dynamics of benthic nutrient fluxes using in situ benthic chambers deployed over a 24–hour period at the sediment water interface for four distinct regions of the Knysna Estuary. The sediment in the Upper Estuary, Lagoon and Bay acted as a source of NH4 with a rate of 100–300 µmol m−2 day−1 N, and soluble reactive phosphorus (SRP) with a rate of 15 µmol m−2 day−1 P, whereas that of Ashmead channel exceeded these rates by far. The sediment acted as a sink for NO3− with fluxes of between −200 and 100 µmol m−2 h−1. Benthic nutrient fluxes in the estuary were positively related with sediment organic content and silt. Nutrient fluxes in the Ashmead channel were significantly greater than the other regions because of the anoxic sediment, reduced flushing and a legacy of pollutant and organic matter retention. This condition can only be improved by removing wastewater input and dredging. Such drastic interventions are necessary to improve the health of South Africa’s top ranked estuary in terms of biodiversity importance. DA - 2020/04/02/ PY - 2020 DO - 10.2989/16085914.2019.1671787 DP - Taylor and Francis+NEJM VL - 45 IS - 1-2 SP - 1 EP - 9 SN - 1608-5914 UR - https://doi.org/10.2989/16085914.2019.1671787 Y2 - 2022/08/26/10:27:40 KW - anoxic sediment KW - biodiversity KW - eutrophication KW - fine sands KW - organic content KW - pollutant retention KW - water quality ER -