The concentration of magnesium and potassium in sea water, in abalone, and Sargassum sp. in rainy season and dry season

Abstract

The increasing global demand for high-protein foods has heightened interest in high-quality fishery products such as abalone. This study examined seasonal variations in magnesium (Mg²⁺) and potassium (K⁺) concentrations in natural abalone (Haliotis squamata) tissues, surrounding seawater, and associated Sargassum sp. Sampels were collected during the rainy and dry seasons of 2023 from coastal waters in Pekutatan, Jembrana, Bali. Ion concentrations were measured using atomic absorption spectrophotometry (AAS), and proximate composition was analyzed for both abalone meat and Sargassum sp. Results revealed higher Mg²⁺ and K⁺ concentrations in abalone meat and shell during the rainy season. Similarly, Sargassum sp. showed greater ion accumulation during the rainy season, while seawater displayed contrasting trends: Mg²⁺ levels were higher in the dry season, whereas K⁺ levels increased during the rainy season. Proximate analysis indicated higher protein (48.03 ± 0.89%) and moisture (21.56 ± 0.90%) contents in abalone meat during the rainy season. In contrast, most nutrient components in Sargassum sp. peaked during the dry season, except for ash content, which was highest during the rainy season (48.94 ± 0.63%). These findings suggest that seasonal changes significantly affect ionic uptake and nutritional quality in aquatic organisms through complex environmental-physiological interactions.

Keywords: Haliotis squamata, magnesium, potassium, Sargassum sp., seasonal variation