Gastropod Community and Coliform Contamination in Langihan Lagoon: A Call for Improved Sanitation Management

Freshwater ecosystems in urban areas are increasingly threatened by biological contamination and declining water quality, posing risks to biodiversity and public health. Survey and inventory of gastropods in Langihan Lagoon, Butuan City, Philippines and the examination of snail’s coelomic contents were conducted. Total coliform counts and basic physico-chemical features of the lagoon were also assessed. Results revealed a total of 1,389 freshwater snail individuals from five species (Pomacea canaliculata, Gyraulus sp., Melanoides maculata, and Mieniplotia scabra) from four families. Artificial shedding and dissection of the snails’ body cavity showed the absence of any cercaria. However, sporocysts, hookworm eggs and two species of bdelloid rotifers (Rotaria sp. and Philodina sp.) were isolated from P. canaliculata. Physico-chemical parameters from all study stations were within the standard limits except the high salinity and low DO levels during dry season and the low pH during wet season assessment. Total coliform tests indicate the highest probable presence of coliform (>1,6000 MPN/100mL) from all stations across seasons which imply high risk of exposure to coliform-associated diseases when in contact with the lagoon water. Improved management of the lagoon to improve water quality and reduce the coliform contamination in the area is recommended.