Health, Environment, and Community Well-Being

Microbial Abundance and Coliform Contamination in the Gut of Lambis lambis from Recreational Water of Cowrie Island, Honda Bay, Palawan

Ezekiel C. Remiendo, Avien Ynna M. Hasan, Jhonamie A. Mabuhay-Omar

Abstract

The gut microbiota of marine mollusks reflects both their dietary inputs and exposure to environmental contaminants, making them valuable indicators of microbial ecology in coastal ecosystems. This study investigated the microbial abundance and coliform contamination in the gut of Lambis lambis collected from Cowrie Island, Honda Bay, with the objectives of quantifying the abundance of microbial bacteria and fungi and determining coliform levels using the Most Probable Number (MPN) method. A total of ten (10) adult specimens were collected and analyzed using culture–based microbiological techniques. Microbial abundance was determined through serial dilution and plate count methods. Coliform levels were assessed using the conventional three–tube MPN method. Results showed that bacterial populations were consistently higher than fungal populations, with bacterial counts ranging from 19.5 × 10⁴ to 57.1 × 10⁴ CFU/g, while fungal counts ranged from 1.67 × 10⁴ to 7.7 × 10⁴ CFU/g. Coliform analysis revealed MPN values ranging from 150 to 460 MPN/100 mL, all exceeding the recommended standard limit of 100 MPN/100 mL. The elevated coliform counts indicate exposure of L. lambis to contaminated marine environments, possibly influenced by anthropogenic activities such as tourism and coastal pollution. The findings suggest that bacteria dominate the gut microbiota of L. lambis and that the species may serve as a potential bioindicator of microbial pollution in coastal ecosystems. This study provides baseline information on the microbial ecology and environmental conditions of recreational marine waters in Honda Bay, Palawan.