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International Journal of Marine Science 2014, Vol.4, No.66, 1-11
http://ijms.biopublisher.ca
5
Taxa of Rhodophyta were found in highest number (6
species) in October and less (3 species) in June.
Members of Chlorophyta were found in highest
number (9 species) in June. Members of Ochrophyta
(5 species) were found in highest number in April.
During June, only one species of Ochrophyta
(
Sargassum cinctum
J. Agardh) was found.
Iyengaria
stellata
was found throughout the three sampling
months.
Caulerpa
species dominated during April as
compared to June and October during the sampling
months.
Caulerpa
sp. (
C. racemosa
(Forsskål) J. Agardh,
C.
sertularioides
(S. Gmelin) F. brevipes (J. Agardh)
Svedelius,
C. veravalensis
Thivy & Chauhan,
C.
taxifoila
(Vahl) C. Agardh) were found in mature
condition in April which indicated summer growth
stage.
Hypnea spinella
(C. Agardh) Kützing and
Stoechospermum marginatum
(C. Agardh) Kützing
was in mature condition only during October which
showed monsoon growth stage.
Ulva
species (
U.
lactuca
Linnaeus and
U. fasciata
Delile) were found
in Juvenile condition in October.
Various researchers have studied seasonal distribution
of marine macroalgae in Indian waters. They have
studied the seasonal variability of macroalgae in the
east and west coast but did not comment on the
dynamics of the macroalgae. Thakur et al
.,
(2008)
have worked on the seasonal variation in biomass and
species composition of seaweeds in port Okha during
May 2004 to April 2005 and reported 62 species
during the entire study period. Studies conducted for
quantifying the standard seaweeds from May 2004 to
April 2005 showed an average biomass value of 3.10
kg fresh wt/m
2
/month with maximum being 6.60 kg
fresh wt/m
2
in April. Dhargalkar and Deshmukhe
(1996) have worked on the subtidal marine algae of
Dwarka
coast and reported 35 marine algal species.
They encountered maximum numbers of species at
5-8m depth and found red algae species dominating
this depth. Other authors have studied seasonal
variability in the species of macroalgae. Ramamoorthy
et al., (2012) have presented an assessment of reef
associated biota in the Pirotan Island, Gulf of Kachchh,
Gujarat and reported 89 species of fauna and 31
species of flora (seaweeds and seagrasses).
This study intends to report the macroalgae taxa on
the basis of a systematic field inventory with reference
to presence and absence of the taxa and its stage of
growth. This kind of study when done on routine
annual basis can bring out the macroalgal dynamics on
spatial and temporal domain for the study area.
3 Material and methods
3.1 Study Area
For macroalgae growth, geographical, geological,
topographical and physical nature of the shore is very
important. The rocky coast has vertical zonation
worldwide (Woodward, 2003): it provides good
platform and stable coastal environment compared to
that of soft sediments coasts like beaches and spits.
Shore platform represents a case environment where
majority of macroalgae species grow with a firm
substratum attachment.
Gujarat coast of India represents the northwestern
most part of peninsular India. This coastline occurs
within geographical limits of 20
00’-24
45’N and
68
00’-78
30’E. It is 1,650 km long with 164,200 km
2
continental shelf (Jha, et al., 2009). It extends in the
form of four major coastal ecological components: i)
Kori creek ii) Gulf of Kachchh iii) Saurashtra coast
from Okha to Porbandar and iv) Gulf of Khambhat.
The substratum is rocky in many parts, which
provides suitable environment for macroalgae growth
(Chakraborty and Bhattacharya, 2012). The Saurashtra
coast, which runs for an approximate length of 985
km, is characterized by rocky, sandy and muddy
intertidal zones, harboring rich and varied flora and
fauna (Gohil and Kundu, 2012).
The present study was carried out on the shore platform
at Dwarka, located on the Saurashtra coast
(22
14’22”-22
14’38”N and 68
57’15”- 68
57’25” E)
(Figure 1). Total length of the study area is 572.28 m,
maximum width sampled is 105.5 m and covers a
surface area of 60375.54 m
2
. Previous surveys of
marine algal resources along the Gujarat coast,
performed at the intertidal zone, have revealed great
diversity of marine algae in this region (Dhargalkar and
Desmukhe, 1996).
3.2 Field data collection
For the present study, the study area was divided
into
three sections (in North-South direction): (i) Northern,
(ii) Central and (iii) Southern sections for convenience