Assessment of relationship between young mangrove and phytoplankton abundance according to different river zoning

Abstract

Phytoplankton plays an important role in the food web of estuarine ecosystems and their communities assume very great ecological significance in mangrove ecosystems. Nevertheless, the disturbance levels in mangrove habitats and seasonal changes have affected phytoplankton abundance, structure, and distribution. Accordingly, the correlation between mangrove age with phytoplankton abundance has been determined in order to find the relationship between these two parameters. More interestingly, the relationship between phytoplankton abundance and river zoning is also assessed considering that high tide would have an effect on the abundance of phytoplankton due to mixing between seawater and freshwater which is considered as contributor to the growth of plankton. The results indicate that the population and compactness of phytoplankton appear higher at the younger mangrove area compared to mature area. This condition is due to the shading produced by the canopy at older mangrove sites, which reduces light availability in the creeks and suppresses phytoplankton growth. The results also discovered that the lowest abundance of phytoplankton is located at upstream of young mangrove areas, while the highest abundance of phytoplankton is located at downstream due to having been carried away by the current heading towards the ocean. This verifies that mangrove age affects the abundance of phytoplankton based on different river zonings. Significantly, the findings will assist the Department of Fisheries Malaysia and agritourism by providing scientific data which will facilitate the maintenance of the mangrove ecosystem and enhance the fishing industry within the area.