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Studies on the Biotechnological Applications of Marine Microalgae
1. Introduction
Marine phytoplankton comprise a complex community of several thousands of
floating microalgae in the sea ranging in size from about 1 pm upto a few millimeters.
Based on their size. phytoplankton can be classified as macroplankton (more than
1mm), microplankton (less than 1mm, retained by nets of mesh size 0.06 mm),
nanoplankton (between 5 and 60 micrometers) and ultraplankton (less than 5
micrometers). Many phytoplankton species belong mainly to the nanoplankton and
microplankton fractions.
Studies on the various aspects of species composition, density, distribution and
seasonal variations of marine phytoplankton relating to coastal waters have been
carried out from various parts of the world by Ignatiades and Mirnicos (1977) from the
Sarnikos Gulf waters; Figueira (1989) from the Spanish waters of Atlantic coast;
Yong (1990) from Maxiwell Bay of George Island and Yamaguchi et al. (1994) from
Thale Sap Songkhia of Thailand.
Fritsch (1935), Singh (1939 a,b; 1942 a,c; 1941), Rao, (1939, 1940) and
Parukutty (1939, 1940) made effective contribution to the Indian flora of algae.
Publications by Iyengar and Desikachary (1944, 1946 a & b, 1953, 1954) and
Desikachary (1945; 1946 a & b, 1953) added considerably to the existing knowledge
of Indian algae, particularly the blue green algal flora of south India.
Chapter I- Species Composition of Marine Microalgae in Arockiapurani Coast
13
Studies on the Biotechnological Applications of Marine Microalgae
In India, such studies have been carried out from the east and west coasts.
Preliminary and systematic accounts on the phytoplankton of Madras coast
(Subrahmanyan, 1946) and the shore waters of Gulf of Mannar (Prasad, 1958) are
found to be very useful and significant. It was Menon (193 1) who reported for the first
time diatoms of the east coast of India. The distribution of phytoplankton of east coast
was studied by Shetty ci al. (1962), Santhakumari (1971), Vijayalakshrni and
Venugopalan (1973), Devendran ci al. (1974), Ramadhas (1977), Premila and Rao
(1977), Ragothaman and Rao (1978), Sundararaj (1978), Thankaraj et al. (1979),
Kannan and Job (1980), Ilangovan (1981), Chandran (1982), Ilangovan and
Krishnamoorthy (1983), Prabha Devi (1986), Mani ci al., (1986). Balusamy (1988),
Subramaniam and Bhavanarayana (1989), Gouda and Panigrahy (1996) and Bharati ci
al. (2001).
This was followed by the contribution to the phytoplankton flora of
Trivandrum coast by Nair (1959). Studies on the phytoplankton of the west coast of
India were carried out by Subrahmanyan (1960), Krishnamoorthy and Viswanathan
(1968), Gopinanthan ci al. (1970). Qasim ci al. (1972), Devassy and Bhattathira
(1974), Joseph and Pillar (1975), Kumaran and Rao (1975), Qasim and Gupta (1981),
Nair ci al. (1983), Rao ci al. (1989) and Nandan and Azis (1996). Lower species
diversity but higher phytoplankton standing crop and chlorophyll concentration have
been reported due to severe eutrophication from the Visakhapatnam harbour waters as
against near normal conditions of the open sea (Raman and Paniprakash, 1989).
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram Coast
14
Studies on the Biotechnological Applications of Marine Microalgae
Seasonal distribution of marine phytoplankton and the seasonal averages of
primary production rates have been reported from different regions of the EEZ of
India (Supriya and Bhargava, 1993). The marine phytoplakton studies were also
carried out from the coastal waters of Tranquebar-Nagapattinam region
(Sampathkumar and Kannan, 1998), 65 species of diatoms, 25 species of
dinoflagellates and one species of blue green alga have been encountered. In the
Mandovi-Zuari nearshore waters of Goa, population density of marine phytoplankton
was studied by Rajagopal (1981); Bhargava and Dwivedi (1974); Bhargava et al.
(1977); Devassy (1983); Verlencar and Qasim (1985).
Phytoplankton characteristics of coastal and estuarine waters of India have also
been investigated by several authors (Jayaraman,1951; George, 1952; Jayaraman and
Seshappa,1957). Similarly, Gopinathan (1985) revealed the new distributional records
on the marine diatoms of Indian seas. Seasonal distribution and behaviour of nutrients
of Mulki estuary was by Vareethiah and Hanifa (1997), Vijayakumar et al. (2000) and
Rajesh et al. (2000). Mathew and Nair (1980) and Vasanthiamma (1991) studied the
planktonic diatoms and hydrography of the Vizhinjam coast.
On the east coast, in the Hooghly estuary of West Bengal, a total of 91 species
of phytoplankton have been recorded (Santra and Pal, 1989). Of these, 18 species
belong to blue greens, 7 to diatoms and 12 to dinoflagellates. Dc ci al. (1994)
observed the maximum number of phytoplankton species during the post-monsoon
Chapter I- Species Composition of Marine Microalgae in Arockiapuram Coast
15
Studies on the Biotechnological Applications of Marine Microalgae
and pre-monsoon seasons and Coscinodiscus radial us and C. excentricus together
contributed 50% of the total population of phytoplankton. Sivadasan and Joseph
(1997) studied the distribution and role of benthic microalgae in Cochin backwater.
Studies on the microalgae of the east coast have received only very attention.
Chapter 1- Species Composition of Marine Microalgae in A rockiapuram Coast
16
Studies on the Biotechnological Applications of Marine Microalgae
2. Material and Methods
Regular monthly collections samples were made from March 2001 to February
2002 from Arockiapuram coast. The microalgae were collected between 5.30 to 7.00
am with the help of a planktonic net of 38p.m mesh size. Immediately after collections
the samples were preserved in 2% formaldehyde. The cells were counted using a
counting chamber under lSOx magnification. Very small forms had to be counted
under with a magnification of 600x. In order to determine the numerical abundance of
phytoplankton depending on the cell concentration, either the whole sample or a part
(lrnl) of it was counted using 9 Sedwig- Rafter counting cell following Trivedi and
God (1986). The values for the whole samples were computed for cells/m 3 of water
and converted to percentage. Based on the climatic conditions prevailing in the
Kanyakurnari District, the study period (2001-2002) was divided into four seasons,
viz., pre-monsoon (March-May), south-west-monsoon (June- September), north-east-
monsoon (October and December) and post - monsoon (January and February).
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram Coast
17
Studies on the Biotechnological Applications of Marine Microalgae
3 Results
The seasonal occurrence of microalgae recorded at Arokiapuram during the
study period, 2001-2002, is presented in Table 1.
A total number of 48 different genera of microalgae were identified
representing 10 classes such as Bacillariophyceae, Chlorophyceae, Chrysophyceae,
Cyanophyceae, Euglenophyceac, Eustimatophyccae, Prasionophyceae,
Prymesiophyceae, Dinophyceae and Chryptophyceae. Among the 10 classes,
Bacillariophyceae was represented by more number of genera (18 numbers), followed
by Chlorophyceae (8 numbers), Prymensiophyceae (6 numbers), Prasinophyceae (5
numbers), Cyanophyceae (3 numbers), Chrysophyceae (2 numbers),
Eustirnatophyceae (2 numbers), Chrptophyceae (2 numbers), Dinophyceae (1 number)
and Euglenophyceae (1 number).
During the pre-monsoon season, among these 48 genera the Dicrateria
inornata was found in maximum (2564 cells/rn 3 ). Next to Dicrateria, the other species
like Coscinodiscus sp. (1296), Pleurosigma sp. (884 cells/rn 3) and Amphiprora
gigantea (764 cells/m 3 ) showed the maximum representation. This was followed by
Fragilaria sp. (481 cells/rn 3), Tetraselmis tetrahele (438 cells/m 3), Chromulina
feibergenesis (382 cells/rn 3 ), Nannochioropsis sauna (283 cells/rn), Chlamydomonas
sp. (251 cells/m 3 ), Chaetoceros calcitrans (233 cells/rn 3) and Streptotheca indica ( 1 84
cells/m, 3), Platymonas sp. (174 cells/m 3), Peridinium sp. (124 cells/m. 3 ), Chiorella
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram Coast
18
Studies on the Biotechnological Applications of Marine Microalgae
marina (103 cells/rn3), Rhizosolenia setigera (83 cells/m3), Chiorella ova/is (74
cells/m. 3), Ch/ore/la salina (62 cells/m 3), Cryptochrysis fulva (60 cells/m3),
Chaetoceros affinis (54 cells/rn 3 ), Navicula sp. (50 cells/rn 3) and Nitzschia closterium
(41 cells/rn 3). The rest of the species were found in negligible numbers (Table I).
Species such as Chroomonas sp., Teiraselmis gracilis, Dicrateria gilva, Isochrysis
galbana and Pavlova lutheri showed no representation in the pre-monsoon samples.
Among the 48 microalgac identified, the Bacillariophyceae constituted 47.27%
(Fig.2), followed by Pryrnensiophyceac (28.86%), Chlorophyceae (7.92%),
Prasinophyceae (5.47%), Chrysophyceae (4.26%), Eustimatophyceae (3.28%),
Dinophyceae (1.38%), Chryptophyceae (0.73%), Cyanophyceae (0.62%), and
Euglenophyceae (0.17%).
In the south-west-monsoon period, Isochrysis galbana showed the maximum
of 4891 cells/m 3 . followed by other species such as Chromulinafeibergenesis (4533
cells/rn 3 , Coscinodiscus sp. (3894 cells/rn 3), Dicrateria inornata (3581 cells/rn3),
Fragilaria sp. (2693 cells/m 3), P/eurosigma sp. (2094 cells/rn), Nannoch/oropsis
sauna (1784 cells/rn 3 ), Amphiprora gigantea (1681 cells/rn 3), Dicrateria gilva (1480
cells/m 3), P/atymonas (895 cells/m 3 ), Streptotheca indica (705 cells/m), Peridinium
sp. (581 cells/m 3), Chlamydomonas sp. (474 cells/m3), Chiorella marina (361
cells/rn 3), Cryptochrysis fulva (285 cells/m3), Chiorella ovalis (254 cells/rn3),
Tetraselmis tetrahele (231 cells/rn 3) and Chaetoceros calcitrans (186 cells/m'). The
Chapter I- Species Composition of Marine Microalgae in Arockiapuram Coast
19
Studies on the Biotechnological Applications of Marine Microalgae
rest of the species identified had very low percentage only (Table 1). Phaeocystis sp.
showed no representation during this season.
During this south-west-monsoon period, the classes Bacillariophyceae
constituted 39.84% (Fig.3), followed by Prymensiophyceae (31.07%), Chrysophyceae
(14.25%), Chlorophyceae (7.24%), Eustimatophyceae (5.53%), Dinophyceae (1.78%),
Prasinophyceae (1.02%), Chryptophyceac (1.07%), Cyanophyceac (0.34%) and
Eu glenophyceae (0.03%).
During the north-east monsoon period, Isochrysis galbana was found to be in
maximum number (3562 cells/rn 3 ). Next to this, Coscinodiscus sp. (2981 cells/m3),
Dicrateria inornata (2586 cells/rn 3), Amphiprora gigantea (2364 cells/rn3),
Pleurosigma sp. (2255 cells/rn 3), Nannochioropsis sauna (1875 cells/m3),
Chaetoceros calcitran.s' (1772 cells/rn3), Sireptoiheca indica (1653 cells/rn3),
Platyrnonas sp. (1564 cells/m3), Chiorella marina (1028 cells/rn 3), Rhizosolenia
setrigera (985 cells/m 3), Crvpiochysis virescens (694 cells/m 3), Chlamydornonas sp.
(585 cells/m 3), Phaeocystis sp. (484 cells/m 3), Chaetoceros affinis (361 cells/rn3),
Pavlova lutheri (285 cells/rn 3 ) and ChromulinafeibergenesiS (305 cells/m3 ) were seen
in the samples. Species such as Nannochioris atomus, Peridinium sp. and Tetraselmis
carterformis showed no representation during this season.
Among the 48 microalgae identified, the classes Bacillariophyceae constituted
49.39%, followed by Pryrnensiophyceae (25.54%), Chlorophyceae (12.95%),
Chapter I- Species Composition of Marine Microalgae in A rockiapuram Coast
20
Studies on the Biotechnological Applications of Marine Microalgae
Eustimatophyceae (6.81%), Chrypophyceae (1.83%), Cyanophyceae (0.5%),
Chrysophyceae (0.47%), Prasinophyceae (0.46%), and Euglenophyceae (0.12%). The
classes Dinophyceae had no representation (Fig.4) in the samples.
During the post-monsoon season, Dicrateria inornata was found to be
maximum with 3893 cells/m 3, followed by Isochrysis galhana (3256 cells/rn3),
Coscinodiscus sp. (2563 cells/m 3), Pleurosigma (2080 cells/rn 3 ), Fragilaria sp. (1684
cells/rn 3), Chromulina feihergenesis (1578 cells/rn 3), Ainphiprora gigantea (1298
cells/m 3), Platynonas (1163 cells/m 3), Chaetoceros calcitrans (1089 cells/rn3),
Chiorcila marina (854 cells/m 3 ), Peridiniu,n sp. (809 cells/m 3), Streptotheca indica
(775 eel ls/rn 3), Nannochioropsis sauna (693 cells/m 3), Phaeocystis (656 cells/m 3),
Ch/ore/la ova/is (569 cells/rn 3), Rhizosolenia setigera (486 cells/rn 3 ), Dicarteria gilva
(395 cells/rn 3 ), Chlamydomonas (296 cells/rn 3 ), Navicula (265 cells/rn 3 ), Chrootnonas
(208 cells/m 3), C,yptochrysis virescens (196 cells/rn 3 ).Cha etoceros affinis (155
cells/rn) and Tetraselmis carter formis (128 cells/m 3). Other species had only poor
presentation (Table 1). Species such as Nannochioropsis atomus, Synechocystis sp.,
Tel raselmis gracilis, Tetraselmis chuii, Pa y/ova salina and Ci yptochiysis fulva
showed no representation during this season.
During this season, the classes Bacillariophyceae constituted 41 .95%, followed
by Pryrnensiophyceae (31.61%), Chlorophyceae (11.66%), Chrysophyceae (6.80%),
Dinophyceae (3.08%), Eustimatophyceae (2.67%), Prasinophyceae (1.06%),
Chapter I- Species Composition of Marine Microalgae in Arockiapuram Coast
21
Studies on the Biotechnological Applications of Marine Microalgae
Chryptophyceae (0.74%) Cyanophyceae (0.28%), and Euglenophyceae (0.11%) as
given in Fig. 5.
The abundance of phytoplankton showed fluctuation during different seasons
of the study period. Among the 48 species of microalgae identified, the class
Bacilariophyceae came first with maximum number and it comprised 66.4% of total
population. The Pyremenesiophyceae constituted 29.3% in the total population. The
other classes such as Chlorophyceae, Chrysophyceae, Eumastigophyceac,
Pyrasinophyceae, Cyanophyceae, Dinophyceae, Cryptophyceae and Euglenophyceae
represented 9.5%, 6.5%, 4.6%, 2%, 2,1.4%, 1. 1, and 0.1% respectively (Fig. 6).
Two-way ANOVA test conducted for the population density between algae
(Table 2) was statistically significant (F=l 1.003; P<0.05) whereas non-significant
between seasons (F= 0.16; P>0.5)
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram Coast
22
Studies on the Biotechnological Applications of Marine Microalgae
Table I.I. Seasonal occurrences of Marine Microalgae (cells/M3) in
theArokiapuram sea during March 2001- February 2002
SI. _______ Seasons________ _______Classes Name of the microalgae P.M NEM PSMNo
5 174 291 1081. Bacillariophyceae Amphora sp.
(0.5) (0.53) (1.04) (0.41)
8 156 8 IS2. Bacillariophyceae Asterionellajaponica
(0.08) (0.47) (0.02) (0.05)
3. Bacil lariophyceac Chaetoceros affinis54 191 361 155
(0.60) (5.87) (1.29) (0.59)233 186 1772 1089
4. Bacillariophyccae Chaetoceros calcitrans (2.59) (0.57) (6.37) (4.14)
1296 3894 2981 25635. Bacillariophyceae Coscinodiscussp.
(14.46) (11.97) (10.71) (9.76)
764 1681 2364 12986. Bacillariophyceae Amphiprora gigantea
(8.52) (5.16) (8.49) (4.94)
- 184 705 1653 7757. Bacillariophyceae Streptotheca indica
(2.05) (2.16) (5.94) (2.95)-
24 12 108 948. Bacillariophyceae Cymbella sp.
(0.26) (0.03) (0.38) (0.35)-
12 11 105 819. Bacillariophyccae Fragilaria intermedia
(0.13) (0.03) (0.37) (0.30)
481 2693 110 168410. Bacillariophyceae Fragilariasp.
(5.36) (8.28) (0.39) (6.41)
-- 50 85 9 265II. Bacillariophyccae Naviculasp.
(0.55) (0.26) (0.03) (1.00)
41 - 8 254 8912. Bacillariophyceae Nitzschia closterium
(0.45) (0.02) (0.91) (0.33)
Contd........
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram Coast
23
Studies on the Biotechnological Applications of Marine Microalgae
SeasonsSl• Classes Name of the microalgaeNo
P.M SWM NEM PSM
24 35 95 6413. Bacillariophyceae Nitzschia sp.
(0.10) (0.34) (0.24)
884 2094 2255 208014. Bacillariophyceae Pleurosigma
(9.86) (6.43) (8.10) (7.92)
83 108 985 486IS. Bacillariophyceae Rhizosoleniasetigera
(9.26) (0.33) (3.54) (1.85)
34 124 84 9116. Bacillariophyccae Skeletonema costatum
(0.37) (0.38) (0.30) (0.34)
24 89 208 1517. Bacillariophyceae Thalussionema nitzschioides
(0.26) (0.22) (0.74) (0.05)
36 110 98 6118. Bacillariophyceae Thu lassiosira pseudonana
(0.40) (0.33) (0.35) (0.23)
20 75 65 8319. Chlorophyceae Chiorella vulgaris
(0.22) (0.23) (0.23) (0.31)
62 108 83 7420. Chlorophyceae Chiorella sauna
(0.69) (0.33) (0.29) (0.28)
________ -
74 - 254 71 56921. Chlorophyceae Chiorella ovalis
(0.82) (0.78) (0.25) (2.16)
103 361 1028 85422. Chlorophyceae Chiorella marina
(1.14) (1.11) (3.69) (3.25)
251 474 - 585 29523. Chlorophyceae Chlamydomonassp.
(2.80) (1.45) (2.10) (1.12)
14 38 110 2524. Chlorophyceae Dunaliella sauna
(0.15) (0.11) (0.39) (0.09)
Contd........
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram Coast
SI. ClassesNo I
25. Chlorophyceae
Name of the microalgae
Platymonas
Studies on the Biotechnological Applications of Marine Microalgae
24
33. Eustimatophyceae Nannochioropsis oculata
34. Eustimatophyceae Nannochioropsis sauna
Seasons
P.M SWM NEM PSM174 895 1564 1163
(1.94) (2.75) (5.62) (4.43)
12 41
(0.13) (0.12) - -
382 4533 305 1578
(4.26) (13.93) (1.09) (6.01)
102 205 208
- (0.31) (0.73) (0.79)
26 55 107 34
(0.29) (0.16) (0.38) (0.12)
17 48 12 41
(0.18) (0.14) (0.04) (0.15)
13 8 18 -
(0.14) (0.02) (0.06)
15 Ii 36 29
(0.16) (0.03) (0.12) (0.11)
11 16 22 8
(0.12) (0.04) (0.07) (0.03)
283 1784 1875 693
(3.15) (5.48) (6.74) (2.64)
8 47
- (0.02) (0.16) -
438 231 17 93
(4.88) (0.71) (0.06) (0.35)
23 14 35
(0.25) (0.04) (0.12 -
26. I Chlorophyceae Nannochloris atomus
27. Chrysophyceac Chromulina fi?ibergenesis
28. Chrysophyceae Chroom onus sp
29. I
Cyanophyceae Anabena sp.
30. 1 Cyanophyccae Oscillatoria sp.
31. 1 Cyanophyceae Synechocystis sp.
32. I Euglenophyceae Euglena gracilis
35. I Prasinophyceae Tetraselmis gracilis
36. I Prasinophyceae Tetraselmis tetrahele
37. I
Prasinophyceae Tetraselmis chuii
Contd...
Chapter I- Species Composition of Marine Microalgae in Arockiapuram Coast
KI
Studies on the Biotechnological Applications of Marine Microalgae
SeasonsSI. Classes Name of the microalgaeNo . P.M SWM NEM PSM
16 74 12838. Prasinophyceac Tetraselmis carierformis
17) (0.22) (0.48)
14 5 28 5639. Prasinophyceae Tetraselmis suecica
(0.15) (0.01) (0.10) (0.21)
1480 105 39540. Prymnesiophyceac I)icrateriagilva
- (0.37) (1.50)
2564 3581 2586 389341. Prymnesiophyccae Dicrateria inornata
(28.60) (11.01) (9.29) (14.8)3
4891 3562 325642. Prymnesiophyceae Isochrysisgalbana
- (15.03) (12.8) (12.40)
80 285 9843. Pryrnnesiophyceac Pay/ova luiheri
- (0.24) (1.02) (0.37)
15 72 8344. Prymncsiophyceae Pay/ova sauna
(0.16) (0.22) (0.29) -
8 484 65645. Prymnesiophyceae I'haeocystis sp.
(0.08) - (1.73) (2.49)
124 581 80946. I)inophyceae Peridiniumsp.
(1.38) (1.78) - (3.08)
60 285 6447. Chryptophyceae Cryptochiysisfulva
(0.66) (0.87) (0.23) -
6 - 64 694 19648. Chryptophyceae Ciypiochrysis virescens
(0.06) (0.19) (2.49) (0.75)
Note: Number within parenthesis denotes percentage
P.M= Pre-Monsoon; SWM= South-west-monsoon. NEM North-East Monsoon, PSM Post-Monsoon
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram roast
26
Studies on the Biotechnological Applications of Marine Microalgae
Table 2. Two -way ANOVA of population density of various algae in
different seasons during the study period.
Source of Variation I SS I df I MS I P-value (5%)
Total Variance 1 2027.486 1 191
Variance due to Algae 1591.909 ' 47 33.87041 Significant
Variance due to Seasons 1.560239 3 0.52008 Non-significant
Error Variance 434.016 141 3.078128
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram Coast
Studies on the Biotechnological Applications of Marine Microalgae
Fig. 5 Percentage composition of microalgae during
the Post-Monsoon season at Arockiapuram sea
DBacillariophyceae
-. DChlorophyceae3161
-
41.9 5 -. OChrysophyceaeDCyanophyceae
-- •Eg'nopyceaeDEustimatophyceae
- - 0 Prasinophyceae
1.06--- :- -- :DPrymensiophyceae.DChryptophyceae1
- - - - -028-j 68
30
Chapter I- Species Composition of Marine Microalgae in Arockiapuram Coast
Studies on the Biotechnological Applications of Marine Microalgae
Fig. 5 Percentage composition of microalgae during
the study period Arockiapuram sea
31
6.
9.
., 1.4 1.1
10 Bacillanophyceaeo Prymnesiophyceae0 ChlorophyceaeO ChrysophyceaeD Eumastigophyceae0 Pyrasinophyceae0 CyanophyceaeO DinophyceaeOCryptophyceae
.DEuglenophyceae
66.4
Chapter I- Species Composition of Marine Microalgae in Arockiapuram Coast
32
Studies on the Biotechnological Applications of Marine Microalgae
4. DiscussionIn the present study, wide fluctuations in the population density of
phytoplankton were observed. Similar observations were reported from the Vellar
estuary by Chandrari (1985) and Mandovi-Zuari estuarine complex by Devassy and
Goes (1988). Regini (2004) also observed similar fluctuations in Rajakkamangalam,
Kadiapatinam and Manakkudy estuaries.
In the present study, among the identified classes of phytoplankton,
Bacillariophyceac (diatoms) were found dominant followed by Chlorophyceae and
others. Similar observations of dominance were made by Santhanam (1976) and
Sivakumar (1982) in Vellar estuary, Nair et al. (1987) in Ashtamudi estuary,
Gopinathan (1985) in Veil lake, Jagadeesan (1986) in Coleroon estuary, Balusamy
(1988) in Muthupet estuary and Shibu (1991) in Paravur lake. It is evident from
several works that diatoms and dinoflagellates are the predominant forms foundc
almost throughout the year in most of the Indian waters (Devassy and Bhghira. 1974).
Joseph and Pillai (1975) observed the abundance of diatoms in the monsoon and post-
monsoon seasons from the backwaters of Cochin.
Next to diatoms, dominance of green algae (Chlorophyceae) was recorded in
all the four seasons. Similar observations were reported by Gopinathan (1975) and
Mathew and Nair (1981) from the fresh water zone of Veil lake and Balusamy (1988)
in Muthupet estuary.
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram Coast
33
Studies on the Biotechnological Applications of Marine Microalgae
Jsochysis galbana, Dicarteria inornala and Cocinodiscus sp. were abundant
in all the seasons. This observation was supported by the findings of Asha et al. (2002)
with Coscinodiscus sp. in the Lakshadweep sea.
The percentage abundance of microalgae also depended upon the season.
There were no equal representation of the species and population density during
different seasons of the study period. Some of the algae that represented more in
number on one season could not be counted as the maximum in the other seasons
(Bai, 1997).
The phytoplankton density was found to be high during the monsoon and low
during pre-monsoon season in present study. Ramass (1977) in Porto Novo estuary;
Chandran (1982) in Vellar estuary; Jegadeesan (1986) in Coleroon estuary and Shibu
(1991) in Paravur lake also observed high phytoplankton density during monsoon and
low during pre-monsoon seasons. Chandran (1985) reported that the species
composition, bloom formation and population density were low during premonsoon
because of the greater seaward flushing and poor light penetration in Vellar estuary.
In the percent study 43 species of microalgae were recorded in the pre-
monsoon season, 47 species in south-west-monsoon, 45 species in north-east monsoon
and 42 species in post monsoon period. These findings are partly substantiated with
the observations made by Kannan (1980) on the diatoms species diversity of Porto
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram Coast
34
Studies on the Biotechnological Applications of Marine Microalgae
Novo, Tamil Nadu and De etal. (1994) in the species diversity of Hugh estuary, north
east coast of India.
Kannan (1996) has reported a total number of 126 species of phytoplankton
from Manauli and Hare islands of the Gulf of Mannar. But in the present study only 48
species could be recorded from Arockiapurarn sea.
Chapter 1- Species Composition of Marine Microalgae in Arockiapuram Coast