International Journal of Marine Science 2016, Vol.6, No.28, 1-9
1
Research Article Open Access
Abundance and Diversity of Zooplankton along the Gulf of Mannar Region,
Southeast Coast of India
N. Jeyaraj
1
, S. Ravikumar
1
,
,
C. Rajthilak
1
, S. Prasanna Kumar
1
, P. Santhanam
2
1 Department of Oceanography and Coastal Area Studies, School of Marine Sciences, Alagappa University, Thondi Campus, Thondi 623 409, India
2 Department of Marine Science, School of Marine Sciences, Bharathidasan University, Tiruchirappalli 620 024, India
Corresponding author email
International Journal of Marine Science
2016, Vol.6, No.28 doi
Received: 21 Apr., 2016
Accepted: 01 Aug., 2016
Published: 02 Aug., 2016
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
:
Jeyaraj N., Ravikumar S., Rajthilak C., Kumar S.P., and Santhanam P., 2016, Abundance and Diversity of Zooplankton Along the Gulf of Mannar Region,
Southeast coast of India, International Journal of Marine Science, 6(28): 1-9 (doi
Abstract
The study addresses the abundance and diversity of zooplankton
along the Gulf of Mannar. Sampling was done from the
nine stations. The samples were collected by horizontal hauls using the zooplankton net (150
μ
m mesh size, 0.5 m mouth diameter
and length 1.5 m) fitted with digital flow meter. From the study we recorded a total of 114 species of which the copepods formed the
dominant group in all the stations. Which consists of
Acartia spinicauda, Acartia danae, Pseudodiaptomus aurivilli, Eucalanus
elongatus, Labidocera acuta, Nannocalanus minor, Paracalanus parvus
,
Corycaeus speciosus, Dioithona rigida, Oithona similis,
Metis jousseaumei, Favella brevis
and
Tintinnopsis directa.
The other dominant groups were barnacle nauplii, bivalves, gastropods
larvae etc. The highest abundance (11,733 Nos./m
3
) was recorded in station 2, while the lowest (1,913 Nos./m
3
) was recorded in
station 6. Diversity (H) was higher in the station 4 whereas the lowest diversity was observed from station 5 and no significant
differences in Evenness (J) and Richness (SR) were observed between stations. A chemometric analysis such as cluster analysis (CA)
and principal component analysis (PCA) reveals that, relationship among the zooplankton groups and studied stations. There was not
any significant difference in zooplankton abundance between stations (p> 0.05).
Keywords
Gulf of Mannar; Zooplankton; Species richness; Species association; Cluster analysis; Principal component analysis
1 Introduction
The biodiversity of a marine ecosystem plays an important role in its structure and function, and biodiversity
information is increasingly used in management strategies for conserving harvested resources. Biodiversity
comprises not only species variety, but also diversity in functional groupings and genetic variation within and
among species (Gaston and Spicer, 2004). The Gulf of Mannar lies between India and Sri Lanka. It encompasses
the territorial waters of the Southeast coast of India, from Dhanushkodi in the North to Kanyakumari in the South.
They are located 2 to 10 km from the mainland along the 140 km stretch between Tuticorin and Rameswaram (Lat
8°55'-9°15’N and Long 78°0'-79°16’E). The islands are classified into 4 groups, namely Mandapam group,
Keelakarai group, Vembar group and Tuticorin group. They have fringing coral reefs and patch reefs, seaweeds,
seagrasses and mangroves rising from shallow areas of sea-shore. Each having its own zonation pattern supporting
its own characteristic communities (Kumaraguru
et al
., 2006). They consists of 117 species of corals, 641 species
of crustaceans, 731 species of molluscs, 441 species of fin- fishes, 147 species of seaweeds and 52 species of
seagrasses (Kumaraguru
et al
., 2006). In recent years, there is a tremendous increase in tourism along the Gulf of
Mannar area. As a result, a large quantity of sewage has been dumping into the sea from the mainland. It may lead
to change the physico-chemical characteristics of the coastal waters. However, zooplankton plays vital role in
energy transfer in the aquatic biosphere and their ecology is of considerable interest in assessing the productivity
of the sea (Hunter, 1981 and Jayasiri, 2007). Information dealing with the plankton of the coastal waters Gulf of
Mannar that is of zooplankton is meagre and mostly limited to Maruthanayagam and Subramanian (1999) and
Sridhar
et al
., (2008). As the study area is under the influence of anthropogenic pressure by means of receiving
pollutants from nearby industries, the output of this study will act as a reference for coastal researchers and
environmental planners for environmental impact assessment purpose.
