Spatial analysis of fish diversity and water quality along Malaysian Johor straits

Abstract

The Malaysian Johor Straits, a vital marine ecosystem, faces challenges such as pollution and habitat degradation, threatening its fish populations and biodiversity. This study aimed to assess fish diversity and its relationship with water quality. Three stations were chosen based on different environmental conditions: Station 1 (urban impact), Station 2 (transitional zone), and Station 3 (mangrove influence). Fish specimens were collected using fishing nets, and their sizes measured, while water quality metrics were analyzed. The most abundant species was Selaroides leptolepis with 95 individuals, while Johnius sp. was the least abundant, with only 5 individuals. The results indicated that Station 3, with higher dissolved oxygen and stable salinity, supported the highest fish diversity, highlighting favorable environmental conditions. In contrast, Station 1 exhibited significantly lower fish diversity, likely due to poor water quality, such as lower dissolved oxygen and increased turbidity. Station 2 showed moderate diversity. Geographic Information System (GIS) analysis further confirmed these findings, identifying Station 1 as an area with degraded water quality and reduced fish populations. This study emphasizes the need for targeted management and conservation efforts to improve water quality in the Johor Straits, ensuring the sustainability of its marine ecosystems.