Environmental Assessment of Water Quality and Its Impact on Nutrient Uptake and Mineral Absorption Capacity of Gracilaria and Halymenia Seaweeds in a Verticulture System in Teluk Kodek, North Lombok, NTB, Indonesia

     This study aimed to assess the water quality in Teluk Kodek, North Lombok, and analyze its influence on the nutrient absorption and mineral uptake capacities of Gracilaria and Halymenia seaweeds cultivated in a vertical aquaculture system. A descriptive research approach was employed, combining field surveys with laboratory analyses. Water quality was evaluated by measuring key parameters, including pH, dissolved oxygen (DO), temperature, salinity, and concentrations of ammonia, nitrate, nitrite, and heavy metals. Seaweed mineral absorption was assessed using X-ray fluorescence (XRF), and mineral characterization was conducted via Scanning Electron Microscopy (SEM) with EDX mapping. The results indicate that water quality in Teluk Kodek remains within a range suitable for seaweed cultivation; however, elevated ammonia and nitrate levels pose a potential risk of eutrophication. Nutrient and mineral uptake by Gracilaria and Halymenia was analyzed based on nitrogen, phosphorus, and heavy metal concentrations in the water. Both species demonstrated strong uptake capacities, with Gracilaria showing higher efficiency in absorbing nitrate and phosphorus. These findings provide valuable insights into the application of vertical aquaculture systems as a sustainable strategy for waste management and improving coastal water quality, supporting the advancement of environmentally responsible marine resource utilization.