Distribution and Diversity of Intertidal Macrofauna of Dharmadam Beach, South West Coast of India

• Published in: International journal of marine science 2014-01, Vol.4 (23)
• Main Author: Nandan, S Bijoy
• Format: Article
• Language: English
• Subjects: Emerita; Gastropoda; Marine
• ISSN: 1927-6648; 1927-6648
• DOI: 10.5376/ijms.2014.04.0023

This contribution presents the abundance and diversity of macrofauna in the pristine intertidal regions of Dharmadam beach along the Kerala coast (South West coast of India) during August 2009 to January 2011.The width of the beach is 15-30m, which alternates according to the tidal height. Environmental parameters like salinity, nutrients, conductivity and total dissolved salts analyzed exhibited significant correlation with macrofauna that dwells in the habitat. Gastropods (45.54%), polychaetes (10%), tanaids (43.4%) dominated in the present study. The monthly variations in abundance were displayed by dominant faunal species in various stations but did not show any seasonal variations except that of Emerita holthuisi, which was observed only in pre monsoon (Feb-May) and monsoon (Jun-Sep) months. Analysis of community indices showed monthly variations in species diversity. The peak mean species diversity was observed in station 1 in May, 2009 and Station 2 in December, 2009 and January, 2010.The spatial distribution of some organisms were not even in the study area. The sparse distribution, low richness and higher dominance of organisms were the characteristic feature of community structure. The dissimilarity trend of organisms like polychaetes, gastropods and total groups were discernible by MDS plotting. It best explained the dominance of polychaetes and gastropods on the beach. Assessing the correlation of water quality parameters to the fauna residing in study area BEST (Bio-Env + Stepwise) analysis was done and salinity showed more significance towards fauna. Draftsman plot were also done to observe the interactions of organisms. The highest correlation has been showed by barnacles and gastropods (0.825).The present study discussed the interaction of organisms in the selected habitat with environmental factors prevailing there along with the diversity and abundance.