3. Results

#### 3.1. Chlorophyll 'a'

In the year 2011–2012, the highest and lowest mean chlorophyll 'a' recorded in station 13 (PRM) and station 9 (MON) were 4.81 2.86 and 0.68 0.36 <sup>μ</sup>g l<sup>1</sup> , respectively. During the post monsoon period, the maximum and minimum chlorophyll 'a' recorded was 1.82 1.53 and 0.85 0.55 <sup>μ</sup>g l<sup>1</sup> respectively at station 9 and station 7 (Figure <sup>2</sup>a). In the year 2012–2013, the highest and lowest mean chlorophyll 'a' recorded in station 9 (MON) and station 3 (PRM) were 3.76 1.92 and 1.54 1.04 <sup>μ</sup>g l<sup>1</sup> , respectively. During the post monsoon period, the maximum and minimum chlorophyll 'a' recorded was 2.66 1.79 and 1.92 1.34 <sup>μ</sup>g l<sup>1</sup> respectively at station 7 and station 2 (Figure 2b). In the both sampling years, two way ANOVA showed significant differences between the season (p < 0.001) but not between the stations.

period, the maximum and minimum chlorophyll 'c' recorded was 2.81 2.13 and 1.49 0.83 <sup>μ</sup>g l<sup>1</sup> respectively at station 13 and station 6 (Figure <sup>4</sup>a). In the year 2012–2013, the highest and lowest mean chlorophyll 'c' recorded in station 6 (MON) and station 4 (PRM)

Figure 2. Seasonal and spatial variations in chlorophyll 'a' (a) for the sampling year 2011–2012 and (b) for the sampling

Checklist, Qualitative and Quantitative Analysis of Marine Microalgae from Offshore Visakhapatnam, Bay of…

maximum and minimum chlorophyll 'c' recorded was 3.91 2.09 and 2.91 1.31 <sup>μ</sup>g l<sup>1</sup> respectively at station 7 and station 13 (Figure 4b). In the both sampling years, two way ANOVA showed significant differences between the season (p < 0.001) but not between the

The seasonal mean value for chlorophyll 'a, b, c' for the both sampling year was represented in Table 1. The seasonal mean value for chlorophyll 'a' varied between 1.07 0.86 <sup>μ</sup>g l<sup>1</sup> (MON) and 3.46 2.05 <sup>μ</sup>g l<sup>1</sup> (PRM) in the year 2011–2012. In the year 2012–2013, seasonal mean value fluctuated between 2.11 1.83 <sup>μ</sup>g l<sup>1</sup> (PRM) and 2.9 1.47 <sup>μ</sup>g l<sup>1</sup> (MON). The highest annual mean value 2.42 1.46 <sup>μ</sup>g l<sup>1</sup> was recorded in 2012–2013 and lowest annual mean value 1.98 1.35 <sup>μ</sup>g l<sup>1</sup> was recorded in the sampling year 2011–2012. In the year 2011–2012, the highest and lowest seasonal mean chlorophyll 'b' recorded in pre-monsoon and post

and lowest mean chlorophyll 'b' recorded in monsoon and post monsoon was 3.07 1.33 and

, respectively. The highest and lowest annual average of chlorophyll 'b' was

, respectively. During the post monsoon period, the

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, respectively. In the year 2012–2013, the highest

were 5.34 1.31 and 1.52 1.11 <sup>μ</sup>g l<sup>1</sup>

3.4. Seasonal mean value chlorophyll 'a, b, c'

monsoon was 2.76 1.2 and 1.13 1.07 <sup>μ</sup>g l<sup>1</sup>

stations.

year 2012–2013.

2.07 0.96 <sup>μ</sup>g l<sup>1</sup>

#### 3.2. Chlorophyll 'b'

In the year 2011–2012, the highest and lowest mean chlorophyll 'b' recorded in station 5 (PRM) and station 7 (POM) were 3.15 2.28 and 0.70 0.51 <sup>μ</sup>g l<sup>1</sup> , respectively. During the monsoon period, the maximum and minimum Chlorophyll 'b' recorded was 1.99 1.58 and 0.99 0.48 <sup>μ</sup>g l<sup>1</sup> respectively at station 4 and station 8 (Figure <sup>3</sup>a). In the year 2012–2013, the highest and lowest mean chlorophyll 'b' recorded in station 6 (MON) and station 11 (PRM) were 4.14 2.73 and 1.50 1.35 <sup>μ</sup>g l<sup>1</sup> , respectively. During the post monsoon period, the maximum and minimum chlorophyll 'b' recorded was 2.51 1.79 and 1.69 0.73 <sup>μ</sup>g l<sup>1</sup> respectively at station 7 and station 13 (Figure 3b). In the both sampling years, two way ANOVA showed significant differences between the season (p < 0.001) but not between the stations.

#### 3.3. Chlorophyll 'c'

In the year 2011–2012, the highest and lowest mean chlorophyll 'c' recorded in station 6 (PRM) and station 12 (POM) were 3.52 2.3 and 0.96 0.61 <sup>μ</sup>g l<sup>1</sup> , respectively. During the monsoon

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Figure 2. Seasonal and spatial variations in chlorophyll 'a' (a) for the sampling year 2011–2012 and (b) for the sampling year 2012–2013.

period, the maximum and minimum chlorophyll 'c' recorded was 2.81 2.13 and 1.49 0.83 <sup>μ</sup>g l<sup>1</sup> respectively at station 13 and station 6 (Figure <sup>4</sup>a). In the year 2012–2013, the highest and lowest mean chlorophyll 'c' recorded in station 6 (MON) and station 4 (PRM) were 5.34 1.31 and 1.52 1.11 <sup>μ</sup>g l<sup>1</sup> , respectively. During the post monsoon period, the maximum and minimum chlorophyll 'c' recorded was 3.91 2.09 and 2.91 1.31 <sup>μ</sup>g l<sup>1</sup> respectively at station 7 and station 13 (Figure 4b). In the both sampling years, two way ANOVA showed significant differences between the season (p < 0.001) but not between the stations.

#### 3.4. Seasonal mean value chlorophyll 'a, b, c'

500 ml was transferred into pre-cleaned polyethylene bottles. The filtrate was preserved in 3% neutralized Lugol's iodine solution. All the water samples were filtered with 60-μm size zooplankton net in order to remove the zooplankton and debris. The filtrate was collected into five liters capacity Polyethylene Terephthalate (PET) jar and kept undisturbed for 2 days to achieve complete sedimentation. After sedimentation of phytoplankton, the supernatant solution was siphoned out to concentrate the volume to accurately about 100–200 ml. Concentrated samples were examined under bright field, dark ground illumination and phase contrast at 200, 400 and 1000 magnifications with the help of Axio scope A1 and Primo Vert (Carl Zeiss, Germany) microscopes. Identification of microalgae was done using an inverted research microscope based on standard keys [6–15] and current taxonomical details were been

In the year 2011–2012, the highest and lowest mean chlorophyll 'a' recorded in station 13 (PRM)

monsoon period, the maximum and minimum chlorophyll 'a' recorded was 1.82 1.53 and 0.85 0.55 <sup>μ</sup>g l<sup>1</sup> respectively at station 9 and station 7 (Figure <sup>2</sup>a). In the year 2012–2013, the highest and lowest mean chlorophyll 'a' recorded in station 9 (MON) and station 3 (PRM) were

and minimum chlorophyll 'a' recorded was 2.66 1.79 and 1.92 1.34 <sup>μ</sup>g l<sup>1</sup> respectively at station 7 and station 2 (Figure 2b). In the both sampling years, two way ANOVA showed

In the year 2011–2012, the highest and lowest mean chlorophyll 'b' recorded in station 5 (PRM)

period, the maximum and minimum Chlorophyll 'b' recorded was 1.99 1.58 and 0.99 0.48 <sup>μ</sup>g l<sup>1</sup> respectively at station 4 and station 8 (Figure <sup>3</sup>a). In the year 2012–2013, the highest and lowest mean chlorophyll 'b' recorded in station 6 (MON) and station 11 (PRM)

maximum and minimum chlorophyll 'b' recorded was 2.51 1.79 and 1.69 0.73 <sup>μ</sup>g l<sup>1</sup> respectively at station 7 and station 13 (Figure 3b). In the both sampling years, two way ANOVA showed significant differences between the season (p < 0.001) but not between the

In the year 2011–2012, the highest and lowest mean chlorophyll 'c' recorded in station 6 (PRM)

significant differences between the season (p < 0.001) but not between the stations.

, respectively. During the post

, respectively. During the monsoon

, respectively. During the monsoon

, respectively. During the post monsoon period, the maximum

, respectively. During the post monsoon period, the

updated according to World Register of Marine Species and Algaebase (2015).

and station 9 (MON) were 4.81 2.86 and 0.68 0.36 <sup>μ</sup>g l<sup>1</sup>

and station 7 (POM) were 3.15 2.28 and 0.70 0.51 <sup>μ</sup>g l<sup>1</sup>

and station 12 (POM) were 3.52 2.3 and 0.96 0.61 <sup>μ</sup>g l<sup>1</sup>

3. Results

16 Microalgal Biotechnology

3.1. Chlorophyll 'a'

3.2. Chlorophyll 'b'

stations.

3.3. Chlorophyll 'c'

3.76 1.92 and 1.54 1.04 <sup>μ</sup>g l<sup>1</sup>

were 4.14 2.73 and 1.50 1.35 <sup>μ</sup>g l<sup>1</sup>

The seasonal mean value for chlorophyll 'a, b, c' for the both sampling year was represented in Table 1. The seasonal mean value for chlorophyll 'a' varied between 1.07 0.86 <sup>μ</sup>g l<sup>1</sup> (MON) and 3.46 2.05 <sup>μ</sup>g l<sup>1</sup> (PRM) in the year 2011–2012. In the year 2012–2013, seasonal mean value fluctuated between 2.11 1.83 <sup>μ</sup>g l<sup>1</sup> (PRM) and 2.9 1.47 <sup>μ</sup>g l<sup>1</sup> (MON). The highest annual mean value 2.42 1.46 <sup>μ</sup>g l<sup>1</sup> was recorded in 2012–2013 and lowest annual mean value 1.98 1.35 <sup>μ</sup>g l<sup>1</sup> was recorded in the sampling year 2011–2012. In the year 2011–2012, the highest and lowest seasonal mean chlorophyll 'b' recorded in pre-monsoon and post monsoon was 2.76 1.2 and 1.13 1.07 <sup>μ</sup>g l<sup>1</sup> , respectively. In the year 2012–2013, the highest and lowest mean chlorophyll 'b' recorded in monsoon and post monsoon was 3.07 1.33 and 2.07 0.96 <sup>μ</sup>g l<sup>1</sup> , respectively. The highest and lowest annual average of chlorophyll 'b' was

2.35 1.14 and 1.84 1.6 <sup>μ</sup>g l<sup>1</sup> in 2012–2013 and 2011–2012, respectively. In the year 2011– 2012, the highest and lowest seasonal mean chlorophyll 'c' recorded in pre-monsoon and post

Table 1. Analytical mean values (mean standard deviation) of chlorophyll a b c for the sampling years 2011–2012 and

Chlorophyll Pre-monsoon (n = 112) Monsoon (n = 112) Post monsoon (n = 112) Annual (n = 336)

2011–2012 2012–2013 2011–2012 2012–2013 2011–2012 2012–2013 2011–2012 2012–2013

Checklist, Qualitative and Quantitative Analysis of Marine Microalgae from Offshore Visakhapatnam, Bay of…

3.46 2.056 2.11 1.83 1.07 0.86 2.9 1.47 1.41 1.11 2.24 1.07 1.98 1.35 2.42 1.46

2.76 1.2 1.92 1.14 1.63 1.28 3.07 1.33 1.13 1.07 2.07 0.96 1.84 1.6 2.35 1.14

2.80 1.619 1.98 1.21 2.15 1.75 3.59 1.81 1.28 1.02 3.22 1.18 2.08 2.81 2.93 1.41

highest and lowest mean chlorophyll 'c' recorded in monsoon and pre monsoon was

chlorophyll 'c' was 2.93 1.41 and 2.08 2.81 <sup>μ</sup>g l<sup>1</sup> in 2012–2013 and 2011–2012, respectively.

Microalgae characteristics were given in Table 2. A total of 191 species of microalgae were identified from the 14 study sites along the Visakhapatnam offshore region, Bay of Bengal. Of these, 131 species were recorded under Ochrophyta division (68.58%) (127 species are diatoms (40.84% Centrales, 25.65% Pennales), 3 species belong to silicoflagellates 1.57% and 1 species in Eustigmatophyceae 0.52%), 35 species (18.3%) belong to dinophyta, 11 species (5.76%) belong

1. Ochrophyta 4 38 66 131 68.5 2. Dinophyta 1 7 10 35 18.3 3. Cyanophyta 1 6 8 11 5.76 4. Chloropyta 3 5 5 7 3.66 5. Euglenozoa 1 2 2 4 2.09 6. Haptophyta 2 2 3 3 1.57 Total 12 59 91 191 100 Centrales 1 21 33 78 40.84% Pennales 1 15 30 49 25.65% Dictyochaceae 1 1 2 3 1.57% Monodopsidaceae 1 1 1 1 0.52

, respectively. In the year 2012–2013, the

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, respectively. The highest and lowest annual mean value of

Class Family Genus Species % of species

monsoon was 2.80 1.62 and 1.28 1.02 <sup>μ</sup>g l<sup>1</sup>

3.59 1.81 and 1.98 1.21 <sup>μ</sup>g l<sup>1</sup>

Division Characteristics

Table 2. Characteristics of microalgae for the both sampling years.

3.5. Microalgal diversity

Chlorophyll 'a' (μg l<sup>1</sup> )

Chlorophyll 'b' (μg l<sup>1</sup> )

Chlorophyll 'c' (μg l <sup>1</sup> )

2012–2013.

Figure 3. Seasonal and spatial variations in chlorophyll 'b' (a) for the sampling year 2011–2012 and (b) for the sampling year 2012–2013.

Figure 4. Seasonal and spatial variations in chlorophyll 'c' (a) for the sampling year 2011–2012 and (b) for the sampling year 2012–2013.

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Table 1. Analytical mean values (mean standard deviation) of chlorophyll a b c for the sampling years 2011–2012 and 2012–2013.

2.35 1.14 and 1.84 1.6 <sup>μ</sup>g l<sup>1</sup> in 2012–2013 and 2011–2012, respectively. In the year 2011– 2012, the highest and lowest seasonal mean chlorophyll 'c' recorded in pre-monsoon and post monsoon was 2.80 1.62 and 1.28 1.02 <sup>μ</sup>g l<sup>1</sup> , respectively. In the year 2012–2013, the highest and lowest mean chlorophyll 'c' recorded in monsoon and pre monsoon was 3.59 1.81 and 1.98 1.21 <sup>μ</sup>g l<sup>1</sup> , respectively. The highest and lowest annual mean value of chlorophyll 'c' was 2.93 1.41 and 2.08 2.81 <sup>μ</sup>g l<sup>1</sup> in 2012–2013 and 2011–2012, respectively.

#### 3.5. Microalgal diversity

Figure 3. Seasonal and spatial variations in chlorophyll 'b' (a) for the sampling year 2011–2012 and (b) for the sampling

Figure 4. Seasonal and spatial variations in chlorophyll 'c' (a) for the sampling year 2011–2012 and (b) for the sampling

year 2012–2013.

18 Microalgal Biotechnology

year 2012–2013.

Microalgae characteristics were given in Table 2. A total of 191 species of microalgae were identified from the 14 study sites along the Visakhapatnam offshore region, Bay of Bengal. Of these, 131 species were recorded under Ochrophyta division (68.58%) (127 species are diatoms (40.84% Centrales, 25.65% Pennales), 3 species belong to silicoflagellates 1.57% and 1 species in Eustigmatophyceae 0.52%), 35 species (18.3%) belong to dinophyta, 11 species (5.76%) belong


Table 2. Characteristics of microalgae for the both sampling years.

to cyanophyta, 7 species (3.66%) belong to chlorophyta, 4 species (2.09%) belong to euglenozoa and 3 species (1.57%) belong to haptophyta. The community composition of phytoplankton was dominated by Centrales, which represented by 21 families with 33 genera. Chaetoceros (15 species), Bacteriastrum (5 species), Coscinodiscus and Thalassiosira (6 species) genus were encountered with more than five species and Rhizosolenia and Triceratium genus were recorded with four species under centric diatoms. Pennate diatoms were recorded with 30 genera and 49 species. In pennate diatoms, maximum four species were recorded under the same genus of Pleurosigma and three species were encountered in each genus of Nitzschia, Amphora, Diploneis and Fragilariopsis. In Dinophyta, 7 families and 10 genera were recorded, maximum number of species found in the genus were Neoceratium (8), Protoperidinium (8) Prorocentrum (3) and Dinophysis (4). In Cyanophyta, six families and eight genera were recorded. Trichodesmium, Lyngbya and Schizothrix genus were encountered with two species and remaining genera was observed with single species. In the division of Chlorophyta, 3 classes, 5 families and 5 genera were recorded, in this division species two species was encountered with Tetraselmis and Dunaliella genus. The division Haptophyta was observed with 3 species and 3 genera. In the Euglenozoa division, 2 genera with 4 species were noted and Silicoflagellates was observed with 2 genera and 3 species. During the course of study phytoplankton showed distribution pattern as: Centric diatoms>PennateDiatoms>Dinophyta>Cynophyta>Chloropyta>Euglenozoa>Haptophyta.

diatoms ranged from 33 (MON) to 42 (PRM) from the total of 46. Dinoflagellate showed the variation between 23 (PRM) and 28 (MON) species in the total of 35. Cyanobacteria found to be low in post monsoon (8) and high during pre-monsoon (11) in the total of 11. In the division of haptophyta, species abundance fluctuated between 2 and 3 during pre-monsoon and monsoon, respectively and chlorophyta species ranged from 4 to 7 during monsoon and pre-

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Checklists (species composition) of microalgae on the Visakhapatnam offshore region were summarized in Appendix A. The samples of all station were pooled for seasonal distribution analysis into samples of three season (pre-monsoon, monsoon and post monsoon) which helped in obtaining information about the distribution and species composition (or) diversity of the sea surface water. Abundance of phytoplankton during the study period (191 species) was reported along the Visakhapatnam Coast throughout the sampling years. Six divisions of microalgae Ochrophyta, Dinophyta, Cyanophyta, Chlorophyta, Euglenozoa and Haptophyta were recorded. The class Bacillariophyceae and Coscinodiscophyceae comprised of 36 families, 63 genera and 124 species. Altogether 191 species of microalgae belonging to the classes of Bacillariophyceae, Coscinodiscophyceae, Dinophyceae, Euglenophyceae, Chlorodendrophyceae, Chlorophyceae, Eustigmatophyceae, Dictyophyceae, Prymnesiophyceae, Pavlovophyceae, Trebouxiophyceae and Cyanophyceae were identified. Of these, Tetraselmis gracilis, Dicrateria inornata, Thalassiosira subtilis, Chaetoceros muelleri, Chaetoceros diversus, Skeletonema costatum, Thalassiosira subtilis and Asterionella inflata were considered important species based on the order of their abundance and frequency of occurrence. Present study indicates that the diatoms are the

Microalgal diversity is extremely important to analyze the status of an ecosystem. Local microalgae species have a competitive advantage under the local geographical, climatic and ecological conditions [16]. The levels of chlorophyll are the proof of photosynthetic activities and there was a distinct seasonality observed in the levels of phytoplankton biomass at the study sites. Total phytoplankton representing the maximum concentration of chlorophyll 'a' was recorded along the Visakhapatnam Coast during pre-monsoon (2011–2012) and monsoon (2012–2013). Surface phytoplankton abundance (as chlorophyll 'a' concentration) levels,

monsoon and monsoon periods of the sampling year 2011–2012. In the year 2012–2013, peak

was reported during pre-monsoon (2011–2012) coincided with the period of upwelling and in the year 2012–2013, and the monsoon coincided with large scale mixing between surface river

phyll 'a' was reported for the entire euphotic zone of EEZ of Arabian Sea and it ranged from 0.1 to 96.4 μg l <sup>1</sup> [18]. Chlorophyll 'a' was found between 3.31 and 99.12 μg l <sup>1</sup> in surface

waters and deeper nutrient rich bottom waters [17]. The annual average (13.4 μg l<sup>1</sup>

, occurred in pre-monsoon, with the further smaller peaks in post

, in monsoon. Highest chlorophyll 'a' concentration

) chloro-

monsoon, respectively.

4. Discussion

reached up to 4.81 μg l<sup>1</sup>

chlorophyll levels reached up to 3.76 μg l<sup>1</sup>

3.5.2. Seasonal variations in qualitative abundance of microalgae

dominant group followed by the dinoflagellates and others.


#### 3.5.1. Seasonal variations in qualitative abundance of microalgae

Seasonal variation in microalgae qualitative abundance was given in Table 3. Seasonal fluctuations of species composition in both sampling years varied from 150 (MON) to 161 (PRM). The species from phylum Ochrophyta fluctuated between 103 (PRM 2012–2013) and 115 (PRM 2011–2012). Centric diatoms varied between 66 (POM) and 70 (PRM) in the total of 78. Pennate

Table 3. Quality abundance of microalgae.

diatoms ranged from 33 (MON) to 42 (PRM) from the total of 46. Dinoflagellate showed the variation between 23 (PRM) and 28 (MON) species in the total of 35. Cyanobacteria found to be low in post monsoon (8) and high during pre-monsoon (11) in the total of 11. In the division of haptophyta, species abundance fluctuated between 2 and 3 during pre-monsoon and monsoon, respectively and chlorophyta species ranged from 4 to 7 during monsoon and premonsoon, respectively.

#### 3.5.2. Seasonal variations in qualitative abundance of microalgae

Checklists (species composition) of microalgae on the Visakhapatnam offshore region were summarized in Appendix A. The samples of all station were pooled for seasonal distribution analysis into samples of three season (pre-monsoon, monsoon and post monsoon) which helped in obtaining information about the distribution and species composition (or) diversity of the sea surface water. Abundance of phytoplankton during the study period (191 species) was reported along the Visakhapatnam Coast throughout the sampling years. Six divisions of microalgae Ochrophyta, Dinophyta, Cyanophyta, Chlorophyta, Euglenozoa and Haptophyta were recorded. The class Bacillariophyceae and Coscinodiscophyceae comprised of 36 families, 63 genera and 124 species. Altogether 191 species of microalgae belonging to the classes of Bacillariophyceae, Coscinodiscophyceae, Dinophyceae, Euglenophyceae, Chlorodendrophyceae, Chlorophyceae, Eustigmatophyceae, Dictyophyceae, Prymnesiophyceae, Pavlovophyceae, Trebouxiophyceae and Cyanophyceae were identified. Of these, Tetraselmis gracilis, Dicrateria inornata, Thalassiosira subtilis, Chaetoceros muelleri, Chaetoceros diversus, Skeletonema costatum, Thalassiosira subtilis and Asterionella inflata were considered important species based on the order of their abundance and frequency of occurrence. Present study indicates that the diatoms are the dominant group followed by the dinoflagellates and others.

## 4. Discussion

to cyanophyta, 7 species (3.66%) belong to chlorophyta, 4 species (2.09%) belong to euglenozoa and 3 species (1.57%) belong to haptophyta. The community composition of phytoplankton was dominated by Centrales, which represented by 21 families with 33 genera. Chaetoceros (15 species), Bacteriastrum (5 species), Coscinodiscus and Thalassiosira (6 species) genus were encountered with more than five species and Rhizosolenia and Triceratium genus were recorded with four species under centric diatoms. Pennate diatoms were recorded with 30 genera and 49 species. In pennate diatoms, maximum four species were recorded under the same genus of Pleurosigma and three species were encountered in each genus of Nitzschia, Amphora, Diploneis and Fragilariopsis. In Dinophyta, 7 families and 10 genera were recorded, maximum number of species found in the genus were Neoceratium (8), Protoperidinium (8) Prorocentrum (3) and Dinophysis (4). In Cyanophyta, six families and eight genera were recorded. Trichodesmium, Lyngbya and Schizothrix genus were encountered with two species and remaining genera was observed with single species. In the division of Chlorophyta, 3 classes, 5 families and 5 genera were recorded, in this division species two species was encountered with Tetraselmis and Dunaliella genus. The division Haptophyta was observed with 3 species and 3 genera. In the Euglenozoa division, 2 genera with 4 species were noted and Silicoflagellates was observed with 2 genera and 3 species. During the course of study phytoplankton showed distribution pattern as: Centric diatoms>PennateDiatoms>Dinophyta>Cynophyta>Chloropyta>Eugleno-

Seasonal variation in microalgae qualitative abundance was given in Table 3. Seasonal fluctuations of species composition in both sampling years varied from 150 (MON) to 161 (PRM). The species from phylum Ochrophyta fluctuated between 103 (PRM 2012–2013) and 115 (PRM 2011–2012). Centric diatoms varied between 66 (POM) and 70 (PRM) in the total of 78. Pennate

1. Ochrophyta 115 106 107 110 103 107 2. Dinophyta 23 27 26 26 28 28 3. Cyanophyta 11 9 9 10 9 8 4. Chlorophyta 6 7 6 7 4 5 5. Euglenozoa 4 3 2 3 3 3 6. Haptophyta 2 3 2 2 3 2 Total 161 155 154 158 150 153 Centrales 69 68 68 70 67 66 Pennales 42 36 38 37 33 38 Dictyochaceae 3 1 2 2 2 2 Monodopsidaceae 1 1 1 1 1 1

PRM MON POM PRM MON POM

zoa>Haptophyta.

20 Microalgal Biotechnology

Table 3. Quality abundance of microalgae.

3.5.1. Seasonal variations in qualitative abundance of microalgae

Division 2011–2012 2012–2013

Microalgal diversity is extremely important to analyze the status of an ecosystem. Local microalgae species have a competitive advantage under the local geographical, climatic and ecological conditions [16]. The levels of chlorophyll are the proof of photosynthetic activities and there was a distinct seasonality observed in the levels of phytoplankton biomass at the study sites. Total phytoplankton representing the maximum concentration of chlorophyll 'a' was recorded along the Visakhapatnam Coast during pre-monsoon (2011–2012) and monsoon (2012–2013). Surface phytoplankton abundance (as chlorophyll 'a' concentration) levels, reached up to 4.81 μg l<sup>1</sup> , occurred in pre-monsoon, with the further smaller peaks in post monsoon and monsoon periods of the sampling year 2011–2012. In the year 2012–2013, peak chlorophyll levels reached up to 3.76 μg l<sup>1</sup> , in monsoon. Highest chlorophyll 'a' concentration was reported during pre-monsoon (2011–2012) coincided with the period of upwelling and in the year 2012–2013, and the monsoon coincided with large scale mixing between surface river waters and deeper nutrient rich bottom waters [17]. The annual average (13.4 μg l<sup>1</sup> ) chlorophyll 'a' was reported for the entire euphotic zone of EEZ of Arabian Sea and it ranged from 0.1 to 96.4 μg l <sup>1</sup> [18]. Chlorophyll 'a' was found between 3.31 and 99.12 μg l <sup>1</sup> in surface

water off Gopalpur, East coast of India, Bay of Bengal [19] and varied between 0.21 and 30.82 μg l <sup>1</sup> off Mangalore, West Coast of India [20] and the highest value 8.28 μg l <sup>1</sup> was observed during the post monsoon off Cape Comorin [21]. In the present work, the higher concentration of chlorophyll 'b' was recorded during monsoon, 2012–2013 and the West coast also recorded the highest concentration of chlorophyll 'b' (20.41 μg l <sup>1</sup> ) during the monsoon [22]. Relatively high chlorophyll 'b' indicates the presence of ultra or nano-planktonic microalgae coming under the class Chlorophyceae/Euglenophyceae/Prochlorophyceae [23].

Seasonal succession of phytoplankton population indicated that dinoflagellates mainly Neoceratium and protoperidinium as well as silicoflagellates; Dictyocha were dominant population in pre-monsoon periods. In diatoms Rhizosolenia, Guinardia, Thalassiosira, Chaetoceros and Asterionella genus were relatively more dominantly throughout the sampling years. The same sequences in the phytoplankton abundance were reported at East Coast India [45] and from Pakistan 15 species in Navicula was reported [46]. Generally, Skeletonema costatum found to be dominant in this Coast coincides was agree with earlier studies [45, 47, 48]. Chaetoceros species have contributed high in total population of centric diatoms and it is coincided by the findings during pre-monsoon periods [45, 49]. In Sundarbans also diatom reported as dominant group in the overall phytoplankton group and Skeletonema and Chaetoceros are more abundant species

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In the current study, genus Asterionella and Fragilariopsis were observed throughout the year but the highest numbers were observed in the months of April and June 2013. Asterionella japonica bloom and discoloration Off Waltair, East coast [51] and north western Bay of Bengal [52] strongly supporting our findings. Pleurosigma species with five different classes was reported as dominant species in Nizampatnam, East Coast of India [53]. The maximum numbers of diatoms recorded in post monsoon period was only five numbers more than that of pre-monsoon. In waters off Visakhapatnam Coast, some genera of green algae under the division of Chlorophyta i.e. Chlorella, Tetraselmis, and Dunaliella were recorded throughout in both samplings years. Prasinophyceae and Trebouxiophyceae classes were found predominantly along with some prokaryotic and eukaryotic picoplankton species in the same Coast [54]. Highest number of species under chlorophyta was recorded during pre-monsoon periods like cyanophyceae. In contrary, Southwest Coast of India had recorded that the cyanophycean and chlorophycean species distributed during the monsoon period of the years 2006–2008 [22]. As like as centric diatoms, cyanophyta also showed a maximum number of species during premonsoon period, however, the maximum values were obtained for dinoflagellates during monsoon period. The annual mean water temperature 29C for both sampling years supported for the abundance of flagellates throughout the year. The abundance of flagellate species was commonly occurring at higher water temperatures [55]. In the Visakhapatnam coastal waters, Haptophyceae and Prasinophyceae classes were most abundant [56] and 17 species of flagellates represented by 6 diverse groups in the same coastal waters [57]. Dictyocha fibula was recorded during monsoon periods of both the sampling years except during post monsoon (2011–2012) and the same sequence were reported the lower abundance of oceanic species

Chlorophyll concentrations and diversity of microalgae in Visakhapatnam offshore region studied in detail for a period of 2 year (2011–2012 and 2012–2013). Our results revealed that the diatoms were found to be dominant with number of species in Visakhapatnam offshore waters, Bay of Bengal. From this study, we had found the suitable spatial and season to get sea water to isolate particular species of microalgae and which is use full for shrimp hatchery in

East Coast of India [50].

Dictyocha fibula during pre- and post-monsoon [58].

5. Conclusion

Chlorophyll 'c' was recorded in lower concentrations during the pre and post monsoon season (2012–2013) and the same pattern was also observed in West Coast of India [22]. Lowest chlorophyll and DO concentrations were recorded during pre-monsoon period (2012–2013) has clearly indicated that plankton growth during pre-monsoon was reduced because of oxygen demand by the organic matter in the period of May and June [24]. The highest seasonal average of chlorophyll 'a', 'b' and 'c' in all stations were recorded during the monsoon of 2012– 2013 due to the nutrient rich land runoff water in to the coastal areas. Monsoon rains and associated land runoff and nutrient loading determines the balance of organic to inorganic loadings which act as major factors controlling community responses of microalgae [25].

Earlier studies have reported that the nutrient supply could have significant effect on community composition of phytoplankton [26]. The nitrogen limitation is known to have a significant effect on phytoplankton composition. To determine the growth of phytoplankton, nutrients are the primary factors. The highly seasonal nature of monsoon rains might have increased the concentration nutrients (nitrite, nitrate and silicate) in monsoon period. The recorded low values during pre- and post-monsoon period may be due to its utilization by phytoplankton as evidenced by high photosynthetic activity and the dominance of neritic seawater having a negligible amount of nitrate [27]. In East Coast of India, Bay of Bengal a total number 249 species of phytoplankton comprising of 131 species of dinoflagellates, 111 species of diatoms and 7 species of cyanobacteria were recorded during 2004 [28]. In 2012, EEZ micro algae distributed studies reported 71 species, 30 genera with 22 families under Bacillariophyceae and 88 species of dinoflagellates encountered with 22 genera and 18 families [29]. In Cyanophyceae, 3 genera with 4 species and in Dictochophyceae one species were also reported in their studies.

Microalgal population (Diatoms>Dinoflagellates>Cyanophyta>Chlorophyta) pattern of this record was similar to that reported from Coastal waters off Rushikulya estuary, East Coast of India [30, 31]. Eurythermal and euryhaline nature of diatoms in all the three season leads to their dominance [32] and have been observed to bloom regularly along the Indian Coast during June to October [33, 34]. Dominance of diatom over dinoflagellates coincides to the report from Indian coastal water [35–37] and world oceans [38, 39]. A cosmopolitan genus such as Chaetoceros was dominant with 15 species followed by other major genera such as Coscinodiscus (6 species), Nitzschia (3 species) and Rhizosolenia (4 species) in this study. Oscillatoriaceae and Phormidiaceae were the dominant family in Cyanophyceae class with 3 species and followed by Schizotrichaceae (2 species) and the trend was similar to the studies in the same coast [40, 41]. Epiphytic cyanobacteria, Dactylococcopsis and Synechococcus and 17 genera belonging to chlorophyceae including Oocystis, Chlorella vulgaris was recorded in Palk Strait [42] and a total 44 species of Cyanobacteria from Tamilnadu [43] and Kerala [44].

Seasonal succession of phytoplankton population indicated that dinoflagellates mainly Neoceratium and protoperidinium as well as silicoflagellates; Dictyocha were dominant population in pre-monsoon periods. In diatoms Rhizosolenia, Guinardia, Thalassiosira, Chaetoceros and Asterionella genus were relatively more dominantly throughout the sampling years. The same sequences in the phytoplankton abundance were reported at East Coast India [45] and from Pakistan 15 species in Navicula was reported [46]. Generally, Skeletonema costatum found to be dominant in this Coast coincides was agree with earlier studies [45, 47, 48]. Chaetoceros species have contributed high in total population of centric diatoms and it is coincided by the findings during pre-monsoon periods [45, 49]. In Sundarbans also diatom reported as dominant group in the overall phytoplankton group and Skeletonema and Chaetoceros are more abundant species East Coast of India [50].

In the current study, genus Asterionella and Fragilariopsis were observed throughout the year but the highest numbers were observed in the months of April and June 2013. Asterionella japonica bloom and discoloration Off Waltair, East coast [51] and north western Bay of Bengal [52] strongly supporting our findings. Pleurosigma species with five different classes was reported as dominant species in Nizampatnam, East Coast of India [53]. The maximum numbers of diatoms recorded in post monsoon period was only five numbers more than that of pre-monsoon. In waters off Visakhapatnam Coast, some genera of green algae under the division of Chlorophyta i.e. Chlorella, Tetraselmis, and Dunaliella were recorded throughout in both samplings years. Prasinophyceae and Trebouxiophyceae classes were found predominantly along with some prokaryotic and eukaryotic picoplankton species in the same Coast [54]. Highest number of species under chlorophyta was recorded during pre-monsoon periods like cyanophyceae. In contrary, Southwest Coast of India had recorded that the cyanophycean and chlorophycean species distributed during the monsoon period of the years 2006–2008 [22]. As like as centric diatoms, cyanophyta also showed a maximum number of species during premonsoon period, however, the maximum values were obtained for dinoflagellates during monsoon period. The annual mean water temperature 29C for both sampling years supported for the abundance of flagellates throughout the year. The abundance of flagellate species was commonly occurring at higher water temperatures [55]. In the Visakhapatnam coastal waters, Haptophyceae and Prasinophyceae classes were most abundant [56] and 17 species of flagellates represented by 6 diverse groups in the same coastal waters [57]. Dictyocha fibula was recorded during monsoon periods of both the sampling years except during post monsoon (2011–2012) and the same sequence were reported the lower abundance of oceanic species Dictyocha fibula during pre- and post-monsoon [58].

## 5. Conclusion

water off Gopalpur, East coast of India, Bay of Bengal [19] and varied between 0.21 and 30.82 μg l <sup>1</sup> off Mangalore, West Coast of India [20] and the highest value 8.28 μg l <sup>1</sup> was observed during the post monsoon off Cape Comorin [21]. In the present work, the higher concentration of chlorophyll 'b' was recorded during monsoon, 2012–2013 and the West coast

[22]. Relatively high chlorophyll 'b' indicates the presence of ultra or nano-planktonic microalgae coming under the class Chlorophyceae/Euglenophyceae/Prochlorophyceae [23].

Chlorophyll 'c' was recorded in lower concentrations during the pre and post monsoon season (2012–2013) and the same pattern was also observed in West Coast of India [22]. Lowest chlorophyll and DO concentrations were recorded during pre-monsoon period (2012–2013) has clearly indicated that plankton growth during pre-monsoon was reduced because of oxygen demand by the organic matter in the period of May and June [24]. The highest seasonal average of chlorophyll 'a', 'b' and 'c' in all stations were recorded during the monsoon of 2012– 2013 due to the nutrient rich land runoff water in to the coastal areas. Monsoon rains and associated land runoff and nutrient loading determines the balance of organic to inorganic loadings which act as major factors controlling community responses of microalgae [25].

Earlier studies have reported that the nutrient supply could have significant effect on community composition of phytoplankton [26]. The nitrogen limitation is known to have a significant effect on phytoplankton composition. To determine the growth of phytoplankton, nutrients are the primary factors. The highly seasonal nature of monsoon rains might have increased the concentration nutrients (nitrite, nitrate and silicate) in monsoon period. The recorded low values during pre- and post-monsoon period may be due to its utilization by phytoplankton as evidenced by high photosynthetic activity and the dominance of neritic seawater having a negligible amount of nitrate [27]. In East Coast of India, Bay of Bengal a total number 249 species of phytoplankton comprising of 131 species of dinoflagellates, 111 species of diatoms and 7 species of cyanobacteria were recorded during 2004 [28]. In 2012, EEZ micro algae distributed studies reported 71 species, 30 genera with 22 families under Bacillariophyceae and 88 species of dinoflagellates encountered with 22 genera and 18 families [29]. In Cyanophyceae, 3 genera with 4

Microalgal population (Diatoms>Dinoflagellates>Cyanophyta>Chlorophyta) pattern of this record was similar to that reported from Coastal waters off Rushikulya estuary, East Coast of India [30, 31]. Eurythermal and euryhaline nature of diatoms in all the three season leads to their dominance [32] and have been observed to bloom regularly along the Indian Coast during June to October [33, 34]. Dominance of diatom over dinoflagellates coincides to the report from Indian coastal water [35–37] and world oceans [38, 39]. A cosmopolitan genus such as Chaetoceros was dominant with 15 species followed by other major genera such as Coscinodiscus (6 species), Nitzschia (3 species) and Rhizosolenia (4 species) in this study. Oscillatoriaceae and Phormidiaceae were the dominant family in Cyanophyceae class with 3 species and followed by Schizotrichaceae (2 species) and the trend was similar to the studies in the same coast [40, 41]. Epiphytic cyanobacteria, Dactylococcopsis and Synechococcus and 17 genera belonging to chlorophyceae including Oocystis, Chlorella vulgaris was recorded in Palk Strait [42] and a total 44 species of Cyanobacteria from Tamilnadu [43] and Kerala [44].

species and in Dictochophyceae one species were also reported in their studies.

) during the monsoon

also recorded the highest concentration of chlorophyll 'b' (20.41 μg l <sup>1</sup>

22 Microalgal Biotechnology

Chlorophyll concentrations and diversity of microalgae in Visakhapatnam offshore region studied in detail for a period of 2 year (2011–2012 and 2012–2013). Our results revealed that the diatoms were found to be dominant with number of species in Visakhapatnam offshore waters, Bay of Bengal. From this study, we had found the suitable spatial and season to get sea water to isolate particular species of microalgae and which is use full for shrimp hatchery in that coastal zone. And another advantages of this study was pin point spatial of this coastal area may help to isolate microalgae can be grown in open pond without any major contamination to produce biomass for biodiesel production.

CENTRIC DIATIOMS Phylum: Ochrophyta (Cavalier-Smith in Cavalier-Smith & Chao, Class: Coscinodiscophyceae (Round & Crawford in Round, Crawford & Mann, 1990)

16 Chaetoceros diadema (Ehrenberg)

18 Chaetoceros didymus (Ehrenberg,

20 Chaetoceros lorenzianus (Grunow,

21 Chaetoceros messanense (Castracane,

23 Coscinodiscus curvatulus (Grunow in

25 Coscinodiscus radiatus (Ehrenberg,

26 Coscinodiscus centralis (Ehrenberg,

27 Coscinodiscus jonesianus (Greville)

28 Coscinodiscus perforatus (Ehrenberg,

32 Actinoptychus campanulifer (Schmidt,

33 Hemiaulus hauckki (Grunow) ex van

34 Hemiaulus membranaceus (Cleve,

22 Chaetoceros paradoxus Var. eibenii (Grounow) Grounow, 1896

Schmidt, 1878)

19 Chaetoceros laevis (Leudugerfortmoral, 1892)

Gran, 1897

1845)

1863)

1875)

1840)

1844)

1844)

1875)

1873)

Heurck, 1882

Ostenfeld

S. No Family S. No Species PRM MON POM PRM MON POM

Checklist, Qualitative and Quantitative Analysis of Marine Microalgae from Offshore Visakhapatnam, Bay of…

13 Chaetoceros tortissimus (Gran, 1900) — + ++ — +

14 Chaetoceros curvisetus (Cleve, 1889) ++ + + + + 15 Chaetoceros decipiens (Cleve, 1873) ++ + + + +

17 Chaetoceros diversus (Cleve, 1873) ++ + + + +

24 Coscinodiscus granii (Gough, 1905) + + — + + —

29 Corethron hystrix (Hensen, 1887) ++ + + + + 30 Corethron inerme (Karsten, 1905) ++ + + + +

31 Gosleriella tropica (Schutt 1892) + — — + — —

2011–2012 2012–2013

http://dx.doi.org/10.5772/intechopen.75549

25

— — + — + —

+ — — + — —

++ + + + +

— + ++ + +

+ + — + + —

+ + — + — —

++ + + + +

+ + — + — —

++ + + + +

— — + — + +

— — + — + +

++ + — + +

++ + + + +

+ — — + + —

1996)

4 Coscinodiscaceae (Kutzing, 1844)

5 Corethraceae (Lebour, 1930)

6 Gossleriellaceae

7 Heliopeltaceae (Smith, 1872)

8 Hemiaulaceae (Heiberg, 1863)

(Round in Round et al. 1990)
