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International Journal of Marine Science 2014, Vol.4, No.23, 210-218
http://ijms.biopublisher.ca
217
lesser steeper profiles offers the area a unique
impression (Figure 10). In every year, this zone
experiences a tropical climate characterized by
South-West monsoon (Jun-Sep), post monsoon (Oct-
Jan), and pre monsoon (Feb- May). South-West
monsoon (seasonal reversal of winds and associated
rainfall) is prominent and heavy beach erosion befalls
during this period. Besides the precipitation the beach
has fresh water influx through a river mouth
(Anjarakkandi River). The arms of this river enter
from two sides of the beach (North & South). Two
stations were selected for the study. On both stations
sandy characters are predominate. But at station 2
mixed type of sediment composition is persists. Fine
sand adhering with scattered laterite rock formation
gives the beach a unique appearance. The beach
boards an array of macrofauna. Before assaying the
abiding macrofauna, the reconnaissance of environmental
factors were carried out.
Figure 10 Map showing location of study area
3.2 Sampling methods
The intertidal zones of Dharmadam beach was
monitored from 2009 August to January 2011. Low
tide time has chosen to sample the area. Two
localities at 500m apart were selected for intensive
sampling. A 15-30m transect was established from
above the drift line to below the swash line with
four regularly marked stations. At the précised
stations a metal quadrate of 25x25cm area were
sited and the sediment within the quadrate were
collected and sieved through 0.5mm mesh sieve
(Anastasios Elftheriou and Alasdair McIntyre, 2005).
The retained organisms in the sieve were preserved in
5% buffered formalin and conveyed to the lab for
sorting. The organisms present in the sediment were
sorted out, preserved and identified.
In addition to the faunal component the measurement
of water and sediment samples from the picked zones
were also collected to analyze different physico
chemical parameters. Temperature of the sediment
was measured by using a centigrade thermometer.
Dissolved oxygen was estimated according to
Winkler’s method (Grasshoff et al., 1983). Salinity
was measured by using a Systronics water analyzer
(Model No. 317; accuracy + 0.01) calibrated with std.
seawater (APHA, 2005). Conductivity was recorded
by Systronics digital potentiometer (Model No.318).
Turbidity, pH, and TDS were measured by using
Systronics water analyser (Model No.317) Tidal
heights were estimated from predicted tide tables.
Long shore currents were measured by releasing a
plastic bottle top to the water and determined the
time for it to travel one meter. Three consecutive
readings were taken.
3.3 Analysis of data
Diversity indices were computed according to
Shannon-Wiener diversity (H’) and Pielou’s evenness
index (J’) by using PRIMER Vs. 6.0 (Clarke and
Gorley, 2006). The ordination plot of samples was
also performed by non-metric Multi-dimensional
scaling (MDS) using Euclidean distance as a distance
measure (PRIMER Vs. 6.0) to explore trends between
samples. Statistical analysis like BEST (Bio-Env +
Stepwise) analysis for finding out the combination
patterns that best explains the biological data. The
BEST analysis gives the ‘best’ match between the
multivariate among-sample patterns of an assemblage
and that from environmental variables associated with
those samples (Clarke and Gorley, 2006). Draftsman
scatter plot were also done to find out interaction
between organisms.
Authors Contribution
SBN is the research supervisor. VAP made the experimental
design, data analysis, manuscript preparation.
Acknowledgement
Authors are thankful to the Head, Dept. of Marine Biology,
Microbiology and Biochemistry, Cochin University of Science
and Technology for providing necessary facilities.
References
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Oceanography and Marine Biology - An Annual Review, 28: 381-496.
Ansell A.D., Sivadas P., Narayanan B., and Trevallion A., 1972, The ecology
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