Enhancing Environmental Monitoring Through Predictive Simulation of Water Quality in the Gunung Anyar Mangrove Conservation Area

The vital mangrove ecosystem in Surabaya's Gunung Anyar estuary, an essential coastal buffer and carbon sink, is threatened by persistent and severe water quality degradation from largely unchecked domestic, industrial, and aquaculture pollution. This study utilized a comprehensive, one-year, two-dimensional coupled hydrodynamic and water quality model to analyze the spatiotemporal distribution of six key parameters: Dissolved Oxygen (DO), Phosphate (PO₄), Nitrate (NO₃), Total Suspended Solids (TSS), Salinity, and Temperature. The model confirmed that water quality distribution is highly dynamic and significantly influenced by prevailing local hydrodynamic conditions. A notable correlation between total water depth and the parameters yielded an average of r=0.37, with the strongest relationship observed between nutrients and DO. This inverse relationship is critical, as high nutrient loads from upstream runoff often trigger hypoxic conditions (low DO), which directly threaten the health of the entire aquatic ecosystem. The results alarmingly revealed that at any given time, only 3 to 4 of the 6 parameters met the required quality standards according to the Ministry of Environment's Decree No. 51 of 2004. Spatially, the main river body was identified as the zone with the poorest water quality, marking it as a priority area. Effective management strategies must therefore include upgrading wastewater treatment and controlling industrial discharge. These proactive measures are essential to restore the estuary's ecological balance and ensure the mangrove's long-term survival, aligning with SDGs 14 and 15.