Mangrove Biodiversity Assessment and Heavy Metals Analysis at Uacon Lake, Candelaria, Zambales, Philippines

Abstract

Mangroves provide essential ecosystem goods and services, including shoreline stabilization and protection against soil erosion caused by storm surges, currents, and tides. Despite their importance, mangrove ecosystems are rapidly declining due to human-induced threats. This study assessed the condition of the mangrove ecosystem at Lake Uacon in the province of Zambales, Philippines, by identifying and quantifying mangrove species, examining their distribution and regeneration status, and evaluating their ecological and economic significance to the local community. Heavy metal concentrations in water and sediment were also analyzed to determine potential environmental contamination. Two sampling stations were established, recording 15 mangrove species and 225 individual trees. Sonneratia alba was the dominant species in both stations, with 76 individuals. However, overall species diversity was low, with a Shannon-Weiner Diversity Index (H’) of 1.983. Heavy metal analysis showed that concentrations in water samples were within permissible limits set by the Department of Environment and Natural Resources, but the sediment samples exhibited elevated levels of chromium, iron, nickel, and copper, all above the permissible limit. The findings indicate a degraded mangrove ecosystem with low species biodiversity and heavy metal sediment contamination, highlighting the urgent need for targeted conservation and management interventions of the mangrove ecosystem in Lake Uacon.