Ecology, Environment and Conservation Paper

ENVIRONMENTAL STATUS OF THE MANGROVE ECOSYSTEM IN VALAPATTANAM RIVER BASIN, KERALA

K. Lakshmi, P. N. Unni, N. Neelakandan and P.S. Harikumar

Abstract

Baseline study of the aquatic environment of the mangrove ecosystem of Valapattanam river basin, Kerala was studied. The physicochemical and biological quality of water and sediments of mangrove and non-mangrove areas were assessed. The presence of high amounts of nutrients especially sodium, potassium and organic carbon was a salient feature of the mangrove sites. Seasonal variations in the nutrient content in water and sediments are presented. Benthic fauna of mangrove sites was dominatal by Polychaetes. Bacillaryophyceae and Protozoan dominated the phyto and zooplankton respectively. Estimation of chlorophyll a, b, c and total chlorophyll done during the seasons studied indicated the mangrove sites to be highly productive. Faecal contamination was observed in the sampling sites. The dominant fish species observed were Mughil cephalus, Etro plus suretensis, Lutiganus sp., etc. Prawns and crabs were also abundant in mangrove sites. The dominant mangrove genera are Rhizophora, Avicennia, Sonneratia, Acanthus and Acrostichum. Medicinally important plants were also recorded among mangrove associates. Very high nutrient content, optimum salinity, pH and tidal action in the mangrove environment favours their development and distribution in the river basin.