Distribution of water physico-chemical parameters and biogenic elements in Setiu lagoon during monsoon events as indicator for primary productivity

Abstract

The study was conducted in the Setiu Lagoon, Terengganu involving three sampling periods, namely in May 2007 (post-monsoon), September 2007 (pre-monsoon) and January 2008 (monsoon). Samples of nutrients (NO3--N, NO2--N, NH4+-N, PO4-3-P), primary productivity, chlorophyll-a and physico-chemical parameters of water were collected during low and high tides from 6 stations in the lagoon area and 6 stations in the riverine area except for primary productivity where samples were taken during the pre-monsoon and monsoon seasons only during high tide. Data obtained were analyzed to assess the variations of water quality within Setiu lagoon spatially and temporally subjected to monsoonal events and tidal changes. From the results, the N:P ratio indicated that the study area was mostly N limited especially in the lagoon area. Correlation analysis indicated that phytoplankton consumed more NO3--N during low tide in the post-monsoon (p<0.01) and pre-monsoon season (p<0.05) but during high tide.