Ocean Acidification

Marine environments that are subjected to seasonal changes are increasingly exposed to various factors, such as water pollution, climate change, coastal development, and human impacts. Therefore, this study examined seasonal changes in the main physicochemical parameters of seawater around Dangli Island, Langkawi, Malaysia to better understand the environmental conditions that affect the local marine ecosystem. This study examined seasonal variations in the main physicochemical parameters of seawater such as salinity, temperature, conductivity, pH, dissolved oxygen (DO), Total Ammoniacal Nitrogen (TAN), and Orthophosphate (PO₄³⁻) between twelve monitoring stations D1–D12 around Dangli Island during the Southwest and Northwest Monsoons. The results showed a significant difference between the Southwest Monsoon (SWM) season, which exhibited higher salinity up to 31.16 ppt, temperature up to 30.62°C, and conductivity, while the Northwest Monsoon (NEM) was recorded with cooler temperatures as low as 28.73°C and a slight increase in dissolved oxygen in some areas. This phenomenon causes the ocean to absorb CO₂ and control ocean acidification. Warmer waters during NEM can reduce CO₂ solubility, while cooler, oxygen-rich SWM conditions increase CO₂ uptake, potentially increasing acidification. By studying and understanding how these seasonal conditions affect ocean chemistry, it can help assess the long-term impacts of climate change on the marine environment of Dangli Island and allow us to prepare early conservation strategies for the future. These factors can be influenced by seasonal variations and upwelling phenomena. Two-way ANOVA results demonstrated that all physicochemical parameters have no significant difference between sampling stations (p > 0.05). In addition, there have high significant differences between monsoon seasons (p < 0.05) except for conductivity and DO level. The variations in the physicochemical properties of seawater around Dangli Island reveal the influences of rainfall, river discharges, and upwelling phenomenon on stratification shifts that show the differences in the distribution of seawater physicochemical parameters. These findings also provide valuable insights and help to conserve the marine environment, offering a basis for future research and environmental management strategies around Dangli Island.

Rosmee N. H., Tajam J., Ishak M. A. M., Saleh S. H., Tan A. S. H., Aziz K. N. A. & Ismail M. N., 2026. The Spatial and Temporal Variability Physicochemical Seawater Parameter in Dangli Island of Langkawi, Malaysia. Malaysian Journal of Science and Advanced Technology: 64-72. doi: 10.56532/mjsat.v6iS1.803. Article.