TITLE:
Horizontal Change of Seawater Properties in Marudu Bay, Sabah, Malaysia
AUTHORS:
Sujjat Al Azad, Ejria Saleh, Muhammad Rashid Abdul Rahim
KEYWORDS:
Horizontal Changes, Seawater Properties, Marudu Ba
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.13 No.12,
December
1,
2025
ABSTRACT: Fluctuation of physio-chemical properties in the water column in marine ecosystem can harm the biodiversity of marine organisms and affect the food chain. Marudu bay is part of Tun Mustapha Park (TMP) which is located in the northern part of Sabah. The park area is about 900,000 hectares (ha). The study area covers from Kudat town at the west towards the east side and from Pitas water area down towards the south of the Bay. Twenty-four sampling stations were randomly selected for the physio-chemical properties of seawater measurement and seawater sample collection within Marudu Bay. Data collections were conducted during the northeast, inter-monsoon and southwest monsoon. The in-situ water parameters viz. seawater temperature (˚), salinity (psu), dissolved oxygen (mg/L) and pH were measured using a Hydro Lab DS 5. Horizontal water sampler was used to collect seawater samples for Total Suspended Sediment (TSS) analysis. The data was analyzed and presented by using ArcGIS software version 10.3 to plot the horizontal changes of the properties through inverse Distance Weighted (IDW) method. The recorded ranged of salinity (30.41 - 33.70 psu), dissolved oxygen (3.72 - 6.74 mg/L), pH (8.10 - 8.50), and TSS (0.00 - 14.10 mg/L) were within the National Water Quality Standards for Malaysia (NWQSFM) of Class 1 except for temperature (27.98˚C - 31.15˚C). Dendrogram of the analysed physico-chemical properties and sampling stations shows that there are two distinct clusters of physio-chemical in Marudu Bay with an outlier (station 23). Samples collected during northeast and southwest monsoon season fell under cluster 1 and inter-monsoon under cluster 2, with similarity of about 70% and >80%, respectively. There are three significant principal components (PC) based on the screen plot which PC1 explained 44.67% of correlation while PC2 and PC3 with 28.15% and PC3 19.83%, respectively. PC1 is only positive and affected by dissolved oxygen and not affected by other components while PC2 was positively affected by density and inversely correlated with temperature. PC3 was only affected by pH and negatively correlated with TSS properties.