EFFECTIVENESS OF HALOPHYTIC PLANTS IN THE TREATMENT OF MARINE AQUACULTURE WASTEWATER - GROWTH AND NITROGEN UPTAKE IN Salicornia europaea AND Aster tripolium

摘要

Since nitrogen (N) is essential for plant growth and is incorporated in their tissues, plants have long been used for N removal from different types of wastewater, including from aquaculture. This has been generally restricted to freshwater and low salinity brackish systems, but by using salt tolerant halophytes higher salinity systems can be included(Webb et al. 2012, Buhmann and Papenbrock in press). In addition to N removal, if the selected plants are of commercial interest, they have the potential to become a supplementary crop and provide the grower with extra income. Therefore research into the potential of using halophytes in Integrated Multi-Trophic Aquaculture systems needs to be focussed on plants with economic value - such as Salicomia europaea and Aster tripolium. These plants are of particular interest since they are used as a fresh vegetable, but can also be used as fodder or a component of animal diets. To optimise the performance of economic valuable halophyte filters, both plant production and N removal efficiency need to be investigated. In this study we hypothesized that S. europaea and A. tripolium plants will decrease biomass production with the introduction of routine cropping. Secondly the decrease in biomass will influencethe amount of N removed from water, but the N uptake rates will not be altered.