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International Journal of Marine Science 2014, Vol.4, No.47, 1-11
http://ijms.biopublisher.ca
1
Research Article Open Access
Diversity of infaunal macrobenthic community in the intertidal zone of Vellar
estuary (Southeast coast of India)
A. Hemalatha, K.G.M.T. Ansari , R. Rajasekaran, O.J. Fernando
Centre of Advanced Study in Marine Biology, Faculty of Marine Sciences, Annamalai University, Parangipettai – 608 502, Tamil Nadu, India
Corresponding author email
International Journal of Marine Science, 2014, Vol.4, No.47 doi: 10.5376/ijms.2014.04.0047
Received: 06 Feb., 2014
Accepted: 13 Mar., 2014
Published: 11 Jul., 2014
Copyright
©
2014 Hemalatha et al., This is an open access article published under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Preferred citation for this article:
Hemalatha et al., 2014, Diversity of infaunal macrobenthic community in the intertidal zone of Vellar estuary (Southeast coast of India), International Journal of
Marine Science, Vol.4, No.47 1
-
11 (doi: 10.5376/ijms.2014.04.0047)
Abstract
The diversity and seasonal variations of an intertidal macrobenthic communities linked with abiotic variables were
investigated in the Vellar estuary, Southeast coast of India. Samples were collected seasonally over a one year period from four
transects based on salinity gradients. Totally, twelve infaunal groups were isolated which contained 53 species representing major
taxa. Gastropods were the dominant group (81.6%), followed by polychaetes (7.7%), bivalves (5.5%) and amphipods (5.2%). Among
these
Cerethedia
spp. contributed 61% of all gastropods numerically. The maximum abundance of macrobenthic community was
found at transect II (39%), and the minimum was observed at transect IV (15%), while seasonally marcobenthic abundance was
higher during summer (41%) and lower during monsoon (8%). Diversity (H' log) values varied from 1.859 (transect IV – monsoon)
to 2.467 (transect II –summer). Higher diversity and species richness were found in transect II due to the artificial mangrove
vegetation playing a major role on this region. Univariate and multivariate statistical analyses clearly defined the interaction between
biotic and abiotic variables. The results were compared with the early investigations. Rather similar community structure and species
composition of estuarine macrobenthos indicated no changes of the studied estuarine environment, while higher species diversity
found at the transect II can be interpreted by the artificial mangrove vegetation.
Keywords
Macrobenthos; Community structure; Seasonal variation; Vellar estuary; India
Introduction
Coastal waters including estuaries, back waters, salt
marshes, mangroves and lagoons plays an important
role in exchange of physico-chemical variables in the
environment, particularly estuaries are natural buffer
zones between marine and freshwater areas. Intertidal
benthic organisms are thought to participate an
essential diets of many shorebird and fish species and
can profoundly influence the abundance and species
composition of these tertiary consumers (Alongi, 1990;
Skagen and Oman, 1996), while it also plays an
integral role in the recycling of nutrients and
conservation of water quality within estuarine systems
(e.g. Harris, 1999; Peterson and Heck, 1999). Such
variability in faunal distribution may be further
modified by localized natural and human disturbances
of differential magnitude. According to Currie and
Parry (1999), defining directional change in the biota
of an estuary is inherently unpredictable. An intertidal
environment provides the best study area to observe
the seasonal changes of physico-chemical process in
relation to its inhabitants since a maximum of
fluctuation is met in an estuaries. Few important
studies have been carried out on the macrobenthic
ecology of various estuaries worldwide (e.g. Alongi,
1990; Carvalho et al., 2001;
Herman et al., 2001;
Warwick et al., 2002; Ysebaert et al., 2002
; 2003;
;
Bosire et al., 2004; McLusky and Elloitt, 2004;
Chainho et al., 2006;
Sousa et al., 2007) and in India
(Harkantra, 1975; Ansari et al., 1977; 1982; 1994;
Varshney et al., 1981; Fernando et al., 1984; Fernando,
1987; Vijayakumar et al., 1991; Pillai, 2001; Ajmal
Khan et al., 2004; Raut et al., 2005).
Vellar estuary is well studied area in terms of biotic
and abiotic variables in last four decades (references?).
It is potential and relatively healthy estuary, because
no major sources of pollution other than sewage and
agricultural run-off compared to the other estuaries of
southeast coast of India (Ajmal Khan et al., 2005). An
artificial mangrove, seagrass, oyster bed and
continuous fresh water flow of Vellar estuary provided