Assessment of Oceanographic Trend and Ocean Health Index in The Gulf of Madura

The Gulf of Madura is heavily utilized for shipping, fishing, and oil exploration. These activities impact the marine environment. This study aims to describe the spatial and temporal variability in oceanographic parameters, vertical current structures, trends, and ocean health conditions based on oceanographic parameters estimated from the OHI value. The data used in this research consists of INDESO and Marine Copernicus data. The results of the study show that monsoon phenomena greatly influence temperature and salinity in the Gulf of Madura, with temperature increasing and salinity decreasing during the northwest monsoon, and vice versa during the southeast monsoon. An analysis of oceanographic variables over the past 12 years showed an increase in salinity and nitrate variables, and a decrease in other variables. The trend fluctuation is still within the quality standard for seawater according to government regulation number 22 of 2021. The results of the calculation of the ocean health index show that the Gulf of Madura is in a fair condition with a value of 0.63. This finding can be used to manage and utilize marine space sustainably without deteriorating the ocean’s health.