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Monitoring of Noctiluca bloom in Mandapam and Keelakarai coastal waters; Southeast Coast of India

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Monitoring the Harmful Algal Blooms was carried out during July to December 2008 in Mandapam and Keelakarai coastal waters of Tamil Nadu, Southeast coast of India. In the month of October several fishes and shellfishes were died due to Noctiluca blooms along these two areas. The present investigation the following species of phyto and zooplankton were found to be common; phytoplankton such as Coscinodiscus sp., Skeletonema costatum, Bacillaria paradoxa, Thallassiothrix frauenfeldii, T. longisima, Leptocylindrus sp., and zooplankton such as Paracalanus parvus, Acrocalanus gracilis, Pseudodiaptomus serricautatus, Rhincalanus cornutus, R. nasutus, Euterpina acutifrons, Nannocalanus minor, Eucalanus attenuates, E. crassus, Fish larvae, Fish eggs, Barnacle nauplii, Bivalve larvae, Gastropod larvae, Copepod nauplii and Mysis larvae. The hydrobiological parameters also analysed during bloom and after blooms; the dissolved oxygen (2.6 – 4.9µM L -1) nutrients varied between nitrate (0.66 – 1.01µM L -1) nitrite (0.11 – 0.21µM L -1) phosphate (0.51 – 0.86µM L -1) and silicate (0.81 – 4.2µM L -1).
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Recent Research in Science and Technology 2010, 2(10): 51-58
ISSN: 2076-5061
www.recent-science.com
MARINE BIOLOGY
MONITORING OF NOCTILUCA BLOOM IN MANDAPAM AND KEELAKARAI
COASTAL WATERS; SOUTHEAST COAST OF INDIA
P. Anantharaman, G. Thirumaran, R. Arumugam, R. Ragupathi Raja Kannan, A. Hemalatha,
A. Kannathasan, P. Sampathkumar and T. Balasubramanian
CAS in Marine Biology, Faculty of Marine Science, Annamalai University, Parangipettai – 608 502, Tamil Nadu, India
Abstract
Monitoring the Harmful Algal Blooms was carried out during July to December 2008 in Mandapam and Keelakarai coastal
waters of Tamil Nadu, Southeast coast of India. In the month of October several fishes and shellfishes were died due to
Noctiluca blooms along these two areas. The present investigation the following species of phyto and zooplankton were found
to be common; phytoplankton such as Coscinodiscus sp., Skeletonema costatum, Bacillaria paradoxa, Thallassiothrix
frauenfeldii, T. longisima, Leptocylindrus sp., and zooplankton such as Paracalanus parvus, Acrocalanus gracilis,
Pseudodiaptomus serricautatus, Rhincalanus cornutus, R. nasutus, Euterpina acutifrons, Nannocalanus minor, Eucalanus
attenuates, E. crassus, Fish larvae, Fish eggs, Barnacle nauplii, Bivalve larvae, Gastropod larvae, Copepod nauplii and Mysis
larvae. The hydrobiological parameters also analysed during bloom and after blooms; the dissolved oxygen (2.6 – 4.9µM L-1)
nutrients varied between nitrate (0.66 – 1.01µM L-1) nitrite (0.11 – 0.21µM L-1) phosphate (0.51 – 0.86µM L-1) and silicate
(0.81 – 4.2µM L-1).
Keywords: Noctiluca Bloom, Fish mortality, Mandapam and Keelakarai, Southeast coast
Corresponding Author, Email: paraman_cas@yahoo.co.in, Phone: +914144243223, Fax: +914144243641
Introduction
Harmful algal blooms (HABs) are natural
phenomena that have occurred throughout history.
However, in the past two decades, these events have
increased in frequency, intensity, and geographic
distribution, causing greater public health and
economic effects. Among the 5000 species of extant
marine Phytoplankton (Sournia et al., 1991),
approximately 300 species can occur in such high
numbers that they obviously discolor the sea surface,
and approximately 40 species have the capacity to
produce potent toxins that can transfer through fish and
shellfish to humans (Hallegraeff et al., 1995).
The frequent global occurrence of harmful algal
blooms (HABs) has serious impacts on fishery
resources and the marine environment, and is thus a
pressing topic in marine science. Conventional light
and electron microscopy methods are indispensable
tools for microalgae species identification; however,
they are time consuming and tedious, making it difficult
to assay a large number of samples in long-term
monitoring and high-throughput projects (Scholin et al.,
1996). In addition, the different shapes and sizes of
microalgae in varying environmental conditions or in
different growth stages make them difficult to count,
especially when several morphologically similar algae
coexist in samples (Xin et al., 2005). Consequently,
other techniques, including flow cytometry and
microscopy (FlowCAM) (Sieracki et al., 1998; Jonker et
al., 1995), chemotaxonomy (Mackey et al., 1996; Yao
et al., 2006), spectrofluorometry for algal classes
(Koehne et al., 1999; Jeffrey and Welschmeyer, 1997),
oligonucleotide probes and immunoassays have been
introduced in the field, and now play increasingly
important roles in identifying and monitoring microalgae
(Scholin et al., 1996; Simon et al., 2000).
The bloom and impacts of the mixture on marine
plankton, such as bacterioplankton, heterotrophic
protists and zooplankton, the present investigation was
carried out field experiments through Mandapam to
Keelakarai coastal waters of Tamil Nadu, Southeast
coast of India. Field monitoring in open ocean system
is difficult to conduct because of high spatial and
temporal variability of the site. For these reasons, there
are almost no researches carried out the field
experiment on the open system. This study might be
the first attempt at the field experiment in the ocean.
Materials and Methods
Gulf of Mannar covers approximately an area of
10,500 sq. kms lying between 08˚ 35N - 09˚ 25N and
78˚ 08’ E to 79˚ 30” E. It is unique for its heterogenous
biological resources. The region is not more than 20
meter in depth. There are 21 islands covering of 625
hectares. The islands are classified into 4 groups,
namely Mandapam group, Keelakarai group, Vembar
group and Tuticorin group. The present study has been
made extensively in the Gulf of Mannar. The Gulf of
Mannar is influenced by the south west and North east
monsoon. Although the south west monsoon is rain
during June to September, it does not bring to this
P. Anantharaman et al./Rec Res Sci Tech 2 (2010) 51-58
coast much rain. The north east monsoon which is
prevalent during October to December brings heavy
rain fall to this area. The tidal amplitude here is about
0.75m during the south west monsoon, the coastal
waters in the Gulf of Mannar become turbulent owing
to strong winds. Here the Mandapam and Keelakarai is
a major in the Palk Bay and lot of trawlers are being
operated from this centre and download their catches.
Hydrological parameters
The dissolved oxygen content (ml/l) was analyzed
by modified Winkler’s method (Strickland and Parsons,
1972). For the analysis of nutrients, surface water
samples were collected using clean plastic bucket and
the samples were immediately transported to the
laboratory and filtered through millipore filtering system.
For the analysis of nutrients the standard procedure
described by Strickland and Parsons (1972) was
followed.
Plankton collection and Preservation
The bloom samples were collected using the IOE
plankton net; the mesh size was 335 micron. Paired
plankton (Bongo) nets are cast over the side to collect
phytoplankton such as diatoms and dinoflagellates and
principally zooplankton such as copepods, arrow
worms, and invertebrate larvae also collected all the
way through that. The pair of nets (known as "Bongo
nets") provides some degree of replication for spatial
sampling. Note the sampler at lower left, who is holding
a protractor that enables to estimate the angle of entry
of the wire holding the nets; with this and a measure of
the line that is paid out, one can get an estimate of the
sampling depth. Most plankton nets are equipped with
propeller - driven anemometers, in order to estimate
the linear distance towed. With the cross-sectional area,
this allows the volume of water sampled to be
estimated. Mostly phytoplankton and zooplankton can
be sampled with nets, but they are usually taken with
pumps or automatically closing bottles. The samples
were preserved using 5% diluted formalin and 5%
MgCl2 then the samples were stored in the polythene
containers. Qualitative analysis for the settling method
described by [Sucknova, 1978] was adopted.
Numerical plankton analysis was carried out using
Utermohl’s inverted plankton microscope.
Phytoplankton was identified using the standard
works of various authors [Venkatraman, 1939;
Subramanyan, 1946; Prescott, 1954; Cupp, 1943;
Desikachary, 1959 & 1987; Hendey, 1964, Steindinger
Williams, 1970 and Taylor, 1976] for the sake of
convenience, the phytoplankton collected were
assigned to five major groups diatoms, dinoflagellates.,
blue-green algae, green algae and silico flagellates.
Result
Monitoring the HABs was carried out during July
to December 2008, Mandapam and Keelakarai coastal
waters of Tamil Nadu, Southeast coast of India. In the
month of October several fin fishes and shellfishes
were died due to Noctiluca blooms along these two
areas. Identification of harmful algae (Phytoplankton),
microzooplankton and hydro chemical parameters was
also analyzed. During the study period some species of
phytoplankton were common in these two areas such
as Coscinodiscus sp, Skeletonema costatum, Bacillaria
paradoxa, Thallassiothrix frauenfeldii, T. longisima,
Leptocylindrus sp., Oscillatoria limosa and some
following species moderately occurred such as
Odentella mobiliensis, O. sinensis, Pleurosigma
elongatum, Triceratium favus, T. reticulatum,
Frangilaria oceanica, Rhizosolenia setigera,
Coscinodiscus jonesianus, C. eccentricus,
Lithodesmium undulatum, Nitzschia sp. and
Chaetoceros compressus. Single cell blooms Noctiluca
sp., (Photos 1-3) were recorded during the month of
October and some of the blooms forming species have
been recorded during the month of July and August
such as Ceratium macroceros, C. trichoceros, C. tripos,
C. harridum, C. extensum, C. falcatum, C. inflatum,
and a species of blue – greens (Cyanophyceae),
Trichodesmium erythraeum and Trichodesmium sp.
(Table-1).
P. Anantharaman et al./Rec Res Sci Tech 2 (2010) 51-58
Table 1. Shows the check list of phytoplankton in Mandapam and Keelakarai
S. No. Species Name Mandapam Keelakarai
Family: Coscinodisceae(Diatoms)
1 Coscinodiscus centralis - +
2 C. lineatus + +
3 C. asteromphalus + +
4 C. eccentricus + +
5 C. gigas +
6 C. thorii + +
7 C. jonesianus + +
8 C. radiatus +
9 Planktoniella sol - +
10 Skeletonema costatum - +
11 Thalassiosira
sp. +
12 Cyclotella seriata + +
Family : Triceratiinae (Diatoms)
13 Lithodesmium undulatum - +
14 Ditylum brightwellii + -
15 Triceratium reticulatum + -
16 T. favus - +
Family : Chaetoceraceae (Diatoms)
17 Chaetoceros affini
s
+ -
18 C. curvicetus +
19 C.compressus + +
20 C. dydymus +
21 C. diversus - +
22 C. lorenzianus + +
23 C. peruvians + -
24 C. indicus - +
25 C. diversus + +
26 Bacteriostrum hyalinum + +
27 B. delicatulum + -
28 B. comosum + -
29 B. varians + -
Family: Biddulphoidae (Diatoms)
30 Odentella sinensis + +
31 O. mobiliensis + +
Family : Solenoidae (Diatoms)
32 Leptocylindrus danicus - +
33 L. minimus - +
34 Rhizosolenia styliformis + +
35 R. robusta + -
36 R. stolterfothii +
37 R. crassipina + -
38 R. cylindrus +
39 R. alata + +
40 R. castracanei - +
41 R . setigera + +
42 Guinardia flaccida - +
43 Bacillaria paradoxa - +
44 Isthima inervis + +
Family: Euodicidae (Diatoms)
45 Hemidiscus cuneiformis - +
46 Hemidiscus sinensi
s
- +
Order:Pennales (Diatoms)
Family: Fragilarioideae
47 Climacosphenia moniligera + -
48 C. elongata + -
49 Frangilaria oceanica + -
50 Rhaphoneis
amphiceros - +
51 Thalassionema nitzschioides + +
52 Thalassiothrix frauenfeldii + +
53 Thalassiothrix longissima + +
54 Astrionellapsis
sp. + +
P. Anantharaman et al./Rec Res Sci Tech 2 (2010) 51-58
Family: Naviculaceae
55 Pleurosigma angulatum - +
56 P. elongatum - +
57 Pleurosigma
sp. +
58 P.
normanii - +
59 Gyrosigma sp. - +
60 Nitzshia longissima + +
61 N. sigma +
62 N. seriata - +
63 Nitzschia
sp. - +
64 Navicula hennneydii - +
65 Navicula
sp. + +
66 Cymbella marina - +
67 Pinnularia alpina +
Dinophyceae (Dinoflagellates)
Class: Pyrrophyceae
Order: Dinophysiales
68 Dinophysis caudata + +
Order:Peridiniales
69 Ceratium macroceros + +
70 C. furca +
71 C. tripos + +
72 C. trichoceros + +
73 C.kofoidii +
74 C. falcatum - +
75 C. minutum + +
76 C. horridum - +
77 C. teres - +
78 Protoperidinium oceanicum
79 P.depressum + -
80 Noctiluca
sp. - +
Cyanophyceae (Blue green algae)
81 Trichodesmium
sp. + +
82 Oscillatoria
sp. - +
+ Present - Absent
The present investigation the zooplankton and
microzooplankton was also recorded; from that some
species of zooplankton frequently recorded such as
Paracalanus parvus, Acrocalanus gracilis,
Pseudodiaptomus serricautatus, Rhincalanus cornutus,
R. nasutus, Euterpina acutifrons, Nannocalanus minor,
Eucalanus attenuates, E. crassus, Fish larvae, Fish
eggs, Barnacle nauplii, Bivalve larvae, Gastropod
larvae, Copepod nauplii and Mysis larvae. Some
species were found to be rare in these two coastal
regions such as Luciferhanseni, Microsetella sp.,
Acartia erythrea, Temora turbinata, Centropages
furcatus, Pseudodiaptomus aurivilli and Eucalanus sp.
The microzooplankton like Favella philippinensis, F.
brevis, Globigernia opima and Tintinnopsis sp were
commonly observed during bloom time (Table 1). The
hydrological parameters also analyzed during bloom
and after blooms; the dissolved oxygen (2.6 – 4.9µM L-
1) nutrients varied between nitrate (0.66 – 1.01µM L-1)
nitrite (0.11 – 0.21µM L-1) phosphate (0.51 – 0.86µM L-
1) and silicate (0.81 – 4.2µM L-1) Fig (1-5).
P. Anantharaman et al./Rec Res Sci Tech 2 (2010) 51-58
Table 2. Shows the check list of zooplankton in Mandapam and Keelakarai
S. No. Species Name Mandapam Keelakarai
Zooplankton
Order:Copepoda
Sub order: Calanoida
Family: Calanidae
1 Nannocalanus minor + +
2 Canthocalanus pauper + -
Family: Eucalanidae
3 Rhincalanus sp + +
4 Eucalanus elongatus - +
5 E. crassu
s
- +
Family: Paracalanidae
6 Paracalanus parvus + +
7 P. aculeatus + +
8 Acrocalanus gibber + -
9 A. gracilis + +
10 A. monachus - +
Family: Centropagidae
11 Centropages orsinii + +
12 C. furcatus + -
13 C. tenuiremiss + +
14 C. alcocki + -
15 Isias tropica + -
Family: Pseudodiaptomidae
16 Pseudodiaptomus aurivilli + +
17 P. serricautatus + +
Family:Temoridae
18 Temora
sp. + -
Family: Arietellidae
19 Metacalanus aurivilli + -
Family: Candaciidae
20 Candacia
sp. - +
Family: pontellidae
21 Calanopia
sp. - +
22 C. minor + -
23 Labidocera acuta + -
24 L. pectinata + +
25 L. pavo + -
Family: Acartiidae
26 Acartia spinicauda + +
27 A. erythraea + -
28 A. danae + -
29 A. southwelli - +
Suborder: Harpacticoida
Family: Ectinosomidae
30 Microsetella norvegica + +
Family: Macrosetellidae
31 Macrosetella gracilis + -
32
M. oculata + -
Family: Clytemnestridae
33 Clytemnestra scutellata
+ +
Family: Tachidiidae
34 Euterpina acutifrans + +
Family: Metidae
35 Metis jousseaumei + +
Suborder:Cyclopoida
Family: Oithonidae
36 Oithona similes + +
37 O. brevicornis + +
Family:Corycaeidae
38 Corycaeus danae + -
39 C. catus + -
P. Anantharaman et al./Rec Res Sci Tech 2 (2010) 51-58
Micro-zooplannkton
Foraminifera
40 Globigerna opima + -
41 Globigerna sp. + -
Spirotricha
42 Tintinopsis cylindrica - +
43 T. tocantinesis + -
44 T. beroidea + +
45 Tintinopsis sp. + -
46 Favella brevis + -
47 F. philipiensis + +
Hydroida
48 Obelia
sp. + +
Cladocera
49 Evadne sp. + -
Decapoda
50 Lucifer hanseni + +
Sagittoida
51 Sagitta sp. + -
Larval forms
52 Bivalve veliger + +
53 Gastropod veliger + +
54 Crustacean nauplii - +
55 Copepod nauplii + +
56 Barnacle nauplii + +
57 Cypris larvae of barnacle + -
58 Shrimp larvae + -
59 Crab zoea + +
60 Polychaete larvae - +
61 Fish eggs + +
62 Fish larvae + -
63 Mysis larvae + +
+ Present - Absent
Fig 1. Shows the Dissolved oxygen content during Bloom & after
Bloom Period
MBT - Mandapam Bloom Time; MABT – Mandapam After Bloom
KBT – Keelakarai Bloom Time; KABT – Keelakarai After Bloom
Fig 2. Shows the Nitrate content during Bloom & after Bloom
Period
MBT - Mandapam Bloom Time; MABT – Mandapam After Bloom
KBT – Keelakarai Bloom Time; KABT – Keelakarai After Bloom
P. Anantharaman et al./Rec Res Sci Tech 2 (2010) 51-58
Fig 3. Shows the Nitrite content during Bloom & after Bloom
Period
MBT - Mandapam Bloom Time; MABT – Mandapam After Bloom
KBT – Keelakarai Bloom Time; KABT – Keelakarai After Bloom
Fig 4. Shows the Phosphate content during Bloom & after Bloom
Period
MBT - Mandapam Bloom Time; MABT – Mandapam After Bloom
KBT – Keelakarai Bloom Time; KABT – Keelakarai After Bloom
Fig 5. Shows the Silicate content during Bloom & after Bloom
Period
MBT - Mandapam Bloom Time; MABT – Mandapam After Bloom
KBT – Keelakarai Bloom Time; KABT – Keelakarai After Bloom
Discussion
Harmful algal blooms (HABs) appear to have
increased in frequency, intensity and geographic
distribution worldwide. This increase is not only a threat
to the coastal fish/shellfish aquaculture throughout the
world (Anderson, 1998; Hallegreaff et al., 1995). It is,
however, difficult to quantify such outbreaks in order to
document trends since there are so many different
types of blooms with so many different impacts
(Anderson, 1998). According to the earlier study the
present investigation has reported that fishes and
shellfishes were affected due to Noctiluca bloom.
Available external nutrient supplies can have a
major influence on microalgal. Various workers (Pratt,
1966; Keating, 1977; Sharp et al., 1979) have reported
the presence of toxic metabolites in culture filtrates
from various algae. Myklestad et al. (1995) showed
that cell-free filtrates of P-deficient cultures of
Chrysochromulina strongly inhibited the growth of the
diatom Skeletonema costatum. The addition cultures of
microalgae under nutrient-deficient conditions (N or P)
had a strong negative effect (Skovgaard and Hansen,
2003). The earlier reports strongly supportive to our
present investigation for the period bloom the (N and P)
content is more which enhance the growth of Noctiluca.
In summary, southeast Indian coastal waters has
many HAB species, most of which have increased in
frequency, abundance, regional extent and impact over
the past few decades as population, agriculture and
animal operations, and fertilizer usage have increased.
In addition to increased nutrient loads, the estuaries,
rivers and embayments of the region are also highly
modified by declines in shellfish stocks and wetlands
(e.g., Steel, 1991; Rothschild et al., 1994), leading to
multiple stressors which collectively and synergistically
lead to habitat change and alterations in tropic
structure, including HAB proliferations.
Acknowledgement
This work was supported by a Ministry of Earth
Sciences (Centre for Marine Living Resources and
Ecology – V. N. Sanjeevan) New Delhi, India and the
higher authorities of Annamalai University, Tamil Nadu,
India, for which the authors are grateful.
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... The Indian Ocean (IO) has a distinctive geography amongst the world's oceans; it being the only partially enclosed ocean basin in the world (Rais, 1986). Moreover, bio-physical, bio-chemical and bio-geographical processes of the IO region are not well known compared to the Pacific and the Atlantic Oceans (Alpers, 2013). The knowledge on biogeochemistry of the IO is closely linked to seasonally reversing summer and winter monsoonal winds particularly in the northern IO (Bay of Bengal and Arabian Sea). ...
... Ólafsson and Elmgren, 1997;Moens and Vincx, 1997;Vanaverbeke et al., 2004aVanaverbeke et al., , 2004bFranco et al., 2008). Our findings are also in agreement with global observation; heterogeneity in distribution of trophic status in the study area possibly coincided with the phytoplankton bloom reported from the study region (Anantharaman et al., 2010). Nematode structure and their functions in shelf ecosystem are majorly depended on inputs of materials from the upper euphotic zone (Danovaro, 2012) as well as their interactions with sediments and other organisms (e.g. ...
Article
Depth and latitudinal patterns of nematode functional attributes were investigated from 35 stations of Bay of Bengal (BoB) continental shelf. We aim to address whether depth and latitudinal variations can modify nematode community structure and their functional attributes (trophic diversity, size and biomass spectra). Global trend of depth and latitudinal related variations have also been noticed from BoB shelf in terms of nematode abundance and species richness, albeit heterogeneity patterns were encountered in functional attributes. Index of trophic diversity values revealed higher trophic diversity across the BoB shelf and suggested variety of food resource availability. However, downstream analysis of trophic status showed depth and latitude specific patterns but not reflected in terms of size and biomass spectrum. The peaks at different positions clearly visualized heterogeneity in distribution patterns for both size and biomass spectrum and also there was evidence of availability of diversified food resources. Nematode biomass spectra (NBS) constructed for nematode communities showed shift in peak biomass values towards lower to moderate size classes particularly in shallower depth but did not get reflected in latitudes. However, Chennai and Parangipettai transects demonstrated shift in peak biomass values towards higher biomass classes explaining the representation of higher nematode abundance. Our findings concluded that depth and latitudes are physical variables; they may not directly affect nematode community structure and functional attributes but they might influence the other factors such as food availability, sediment deposition and settlement rate. Our observations suggest that the local factors (seasonal character) of phytodetrital food flux can be very important for shaping the nematode community structure and success of nematode functional heterogeneity patterns across the Bay of Bengal shelf.
... Moreover, from October to December, favorable conditions such as bright sunlight with less cloud cover and estuarine mechanisms seem to stimulate plankton abundance (Gomes et al., 2000;Jyothibabu et al., 2018;Khan et al., 2019). As like our findings, high abundances of plankton during the post-monsoon (October to December) season were also recorded due to the nutrient accumulation during monsoon season in coastal areas of the BoB including Tamil Nadu, Gulf of Mannar, Orissa, Goa and Mangalore (Gopakumar et al., 2009;Sanilkumar et al., 2009;Anantharaman et al., 2010). Furthermore, the plankton biomass from January to June is limited mainly due to inadequate influx of nutrients from the upstream riverine discharge during the dry season and since the entrainment of nutrient-rich water by wind mixing is not efficient in the BoB (Shenoi et al., 2002). ...
Article
Multifaceted linkages among eco-physiological factors, seasonal plankton dynamics and selective feeding behavior of the green mussel (Perna viridis) in the southeast coast of the Bay of Bengal ABSTRACT Feeding behavior of marine bivalves is largely regulated by the interactive effects of various intrinsic biological factors and extrinsic ecological factors. Therefore, an integrated multivariate approach was applied to explore a deeper knowledge about the feeding biology of the green mussel (Perna viridis), collected from the southeast coastal regions of the Bay of Bengal in Bangladesh, by interlinking among ecological factors, seasonal plankton dynamics, reproductive traits and plankton ingestion data. The correlation test, multivariate approaches and cluster analysis displayed that both the water parameters and ingested gut plankton abundance and their compositions were predominantly influenced by the seasonality and ecological factors of the environment. The se-lectivity indices analysis confirmed that green mussels preferentially ingested on the selective taxa of plankton. The multivariate analyses revealed that plankton ingestion by green mussels was not discriminated by their sexual dimorphism, however, it displayed an enhancement during their gonad development and maturation stages confirming that P. viridis espouses opportunistic patterns to build up their gonads by utilizing energy from the ingested planktons available in the water column. The correlation outcomes consistently demonstrated that the quantitative ingestion of plankton was positively correlated with the gonadosomatic index value of the green mussels. Although, green mussels predominantly ingested the Coscinodiscophyceae (20-60% of total ingestion), they also selectively ingested an increased amount of Bacillariophyceae, Fragillariophyceae, Dinophyceae and zooplankton during their gonad development and maturation stages to meet the special and unique metabolic requirements of crucial gametogenesis stages. Taken together all datasets, principal component analysis (PCA) was applied: the first two principal components showed that seasonality and reproductive cycle explained >47% of the variability. In both cases, PCA analysis revealed that the multiplex scenario of selective ingestion of P. viridis on different plankton taxa were predominantly interlinked with the seasonality, ecological drivers, and plankton biomass and their community structure in the water column depending on the metabolic energy requirement during their crucial gametogenesis stages. Finally, the outcomes from these broad datasets provide a better understanding about the selective feeding behavior of P. viridis, which is essential to maintain the sustainability of the ecosystems as well as to improve the growth and productivity of the existing production systems of this important species.
... Till date, in the Mandapam region Rhizosolenia alata and Rhizosolenia imbricata [8], Noctiluca miliaris [17,19]. T. thiebautii [3] and T. erythraeum [1,2,4,13] were reported during the pre-monsoon season. Among these algal blooms, T. erythraeum had resulted mortality of Holothuria atra and fishes in Krusadai Island [2], fishes and crabs in Pamban [4], tuna [13], and several other finfish and shellfish [3]. ...
Article
In April 2019, massive blooms of Trichodesmium erythraeum (8×10 5 filaments/ml) forming several long chains extended up to few kilometres were observed nearby the Mandapam group of islands, Southeast coast of India, Tamil Nadu. Bloom of Synechococcus sp. (3×10 5 cells/ml) was also recorded near the Kundukal jetty, Mandapam region merely. There were no indications of mortality of any fish or other marine organisms during this event. The most probably, "blooms" were favoured by the elevated temperature and salinity. Seasonal monitoring of water quality parameters and observations on these bloom are underway to evaluate the ecological impacts of these cyanobacteria species on coastal fauna for devising management strategies.
... Increasing occurrences and adverse effects of MMBs in marine ecosystems have continued to stir interest in the scientific community ( Anantharaman et al., 2009 ). Coastal habitats are amongst the most affected due to their shallow nature and high susceptibility to changing environmental conditions ( Anderson et al., 2012 ). ...
Article
Full-text available
The Indian marine environment supports employment for over 200 million people, including revenue of nearly $7 billion per annum. However, ecological goods and services of the shallow coast and the marine environment of the Indian peninsula are being affected by recurrent blooms of microalgae. One hundred and six published literature, starting from the first report in 1908 to 2017, were reviewed to investigate the historical occurrences of marine microalgal blooms (MMBs) around the Indian peninsula. 154 MMBs comprising 24 genera and 7 classes were reported during the study period. Noctiluca (dinophyceae) and Trichodesmium (cyanophyceae) bloom contributed 34.4% and 31.8% of total blooms. PCA revealed that high sea surface temperature (SST) and salinity were significant driving forces for Trichodesmium blooms formation, while high nutrients (NO 3-N, PO 4-P, and SiO 4-Si) and low salinity triggered prymne-siophyceae, raphidophyceae, bacillariophyceae and most of the dinophyceae blooms. Noctiluca blooms were linked with both eutrophication and the abundance of prey organisms. HABs were generally dinophyceae dominated and were associated with mass mortality of aquatic fauna, human intoxication, paralytic, and ciguatera shellfish poisoning and even death. Increasing SST and anthropogenic influences around the Indian peninsula could increase the occurrences of MMBs (including HABs) and the number of causative taxa. Proper safety measures such as rou-*
... Moreover, from October to December, favorable conditions such as bright sunlight with less cloud cover and estuarine mechanisms seem to stimulate plankton abundance (Gomes et al., 2000;Jyothibabu et al., 2018;Khan et al., 2019). As like our findings, high abundances of plankton during the post-monsoon (October to December) season were also recorded due to the nutrient accumulation during monsoon season in coastal areas of the BoB including Tamil Nadu, Gulf of Mannar, Orissa, Goa and Mangalore (Gopakumar et al., 2009;Sanilkumar et al., 2009;Anantharaman et al., 2010). Furthermore, the plankton biomass from January to June is limited mainly due to inadequate influx of nutrients from the upstream riverine discharge during the dry season and since the entrainment of nutrient-rich water by wind mixing is not efficient in the BoB (Shenoi et al., 2002). ...
Article
Full-text available
Feeding behavior of marine bivalves is largely regulated by the interactive effects of various intrinsic biological factors and extrinsic ecological factors. Therefore, an integrated multivariate approach was applied to explore a deeper knowledge about the feeding biology of the green mussel (Perna viridis), collected from the south-east coastal regions of the Bay of Bengal in Bangladesh, by interlinking among ecological factors, seasonal plankton dynamics, reproductive traits and plankton ingestion data. The correlation test, multivariate approaches and cluster analysis displayed that both the water parameters and ingested gut plankton abundance and their compositions were predominantly influenced by the seasonality and ecological factors of the environment. The selectivity indices analysis confirmed that green mussels preferentially ingested on the selective taxa of plankton. The multivariate analyses revealed that plankton ingestion by green mussels was not discriminated by their sexual dimorphism, however, it displayed an enhancement during their gonad development and maturation stages confirming that P. viridis espouses opportunistic patterns to build up their gonads by utilizing energy from the ingested planktons available in the water column. The correlation outcomes consistently demonstrated that the quantitative ingestion of plankton was positively correlated with the gonadosomatic index value of the green mussels. Although, green mussels predominantly ingested the Coscinodiscophyceae (20-60% of total ingestion), they also selectively ingested an increased amount of Bacillariophyceae, Fragillariophyceae, Dinophyceae and zooplankton during their gonad development and maturation stages to meet the special and unique metabolic requirements of crucial gametogenesis stages. Taken together all datasets, principal component analysis (PCA) was applied: the first two principal components showed that seasonality and reproductive cycle explained >47% of the variability. In both cases, PCA analysis revealed that the multiplex scenario of selective ingestion of P. viridis on different plankton taxa were predominantly interlinked with the seasonality, ecological drivers, and plankton biomass and their community structure in the water column depending on the metabolic energy requirement during their crucial gametogenesis stages. Finally, the outcomes from these broad datasets provide a better understanding about the selective feeding behavior of P. viridis, which is essential to maintain the sustainability of the ecosystems as well as to improve the growth and productivity of the existing production systems of this important species.
... Nutrient enriched waters and increased sea surface temperature are the major causes of Noctiluca blooms which substantially affecting marine communities (Gopakumar et al. 2008). In South east coast of India, Noctiluca bloom was reported from Gulf of Mannar and Palk Bay which results in sudden death of fishes, sea shells, sea snakes and other benthic fauna (Gopakumar et al. 2008, Prasad 1953, Sampathkumar and Balasubramanian 2010. Gulf of Mannar (GoM) harbours a rich marine biodiversity which composed of 4,223 species of flora and fauna. ...
Article
Full-text available
On 11 th September, 2019, coastal waters near to offshore islands of Mandapam region appeared in dark green colour, which is caused by bioluminescent dinoflagellate Noctiluca scintillans, commonly called as Sea Sparkle. Extensive monitoring was carried out during 11 th to 25 th September, 2019 to assess the impact of this bloom on offshore islands of Mandapam region of Gulf of Mannar coastal fauna. Mass mortality of variety of fish, sea shells and sea snakes washed ashore on Kundukal area in Mandapam region was observed due to the sudden raise of Noctiluca scintillans bloom. No negative impact on coral reefs was recorded from Mandapam group of Islands. Reef building corals remain healthy during and after the bloom formation. There is no significant (p value 0.2111, p<0.05) difference was found in the environmental parameters investigated before and after the bloom formation. Nutrient rich environment and favourable environmental parameters might have helped coral symbionts to respond positively which in turn accelerate the density of zooxanthellae without doing any negative effect on coral holobiont and consequently that leads to maintain a healthy reef condition during this bloom formation.
... centralis (7 × 10 6 cells l −1 ) from Kodikkal, Kerala (Padmakumar et al., 2007) and C. centralis (9.5 × 10 7 cells l −1 ) from Junglighat, South Andaman (Karthik et al., 2014). Studies suggest that diatom algal blooms are common in Indian waters (Bhat and Matondkar, 2004;D'Silva et al., 2012), among which, Trichodesmium and Noctiluca blooms were most frequent (Anantharaman et al., 2010). About, twenty-five algal blooms have been reported in the Indian waters (Table 4) Although C. oculus-iridis has been widely distributed along the Indian coast (Rajkumar et al., 2009;D'Costa and Anil, 2010;, the present study is the first report of an intense bloom of this species. ...
Article
The role of allochthonous nutrient inputs in governing phytoplankton distribution and abundance were assessed from the estuarine regions of the Amba River, west coast of India. A total of 35 species belonging to 24 genera were recorded, where the diatom Coscinodiscus oculus-iridis (99%) dominated the estuarine mouth with a density of 3.5 × 10⁵ cells l⁻¹. Community analyses indicate that diversity (H’) decreased towards the estuarine mouth (0.002 ± 0.001) compared to the middle (0.38 ± 0.06) and inner estuary (1.83 ± 0.14) due to the diatom outbreak. Chlorophyll a reached an average of 12.51 μg l⁻¹ at the estuarine mouth, which is over three times the value determined in the middle estuary (4.25 μg l⁻¹). The key sources of these land-based nutrients are identified as agricultural land and urban runoff for nitrogen (N) and phosphorus (P), extensive sand mining for silica (Si) and aeolian deposition of iron minerals from industrial conveyor belts. A linear correlation between cell density and chlorophyll a with chemical variables indicated that silicate coupled with excess nitrogen input was crucial causative factors for the bloom. The nutrient enrichment towards the estuarine mouth is due to the dispersal of these land derived nutrients by complex hydrological forces.
... Consistently, post-monsoon blooms were usually observed in some coastal areas of the BoB including coast of Mangalore, Goa, Tamil Nadu, and Gulf of Mannar, Orissa. [22][23][24][25] Ideally, after monsoon, cloud cover is reduced and sunlight irradiance enhanced, and therefore, phytoplankton appeared to benefit from both improved light conditions and nutrient inputs from estuarine mechanisms and river runoff. [15] However,the blooming process in the BoB is mainly influenced by seasonal upwelling and monsoonal forcing that causes high riverine discharge, resulting in nutrient-reached water that provides a competitive edge for blooms of phytoplankton species. ...
Article
Full-text available
To test the hypothesis "eutrophication enhances phytoplankton abundances," we analyzed the temporal distribution of phytoplankton and its relationship with nutrients and environmental parameters in the Maheshkhali channel, the southeastern coast of the Bay of Bengal, Bangladesh. The highest abundance of phytoplankton (33 × 10 5 ± 19 × 10 5 cells l −1) was found in October during post-monsoon, which might be due to comparatively higher concentration of nitrate-nitrogen (NO 3-N) (11.62 ± 0.43 µM) and phosphate-phosphorus (PO 4-P) (29.17 ± 02.15 µM), those might have increased from freshwater discharge and precipitation. Phytoplankton was found to be significantly positively related with NO 3-N (r = 0.533, P < 0.01) and PO 4-P (r = 0.719, P < 0.01), and significantly negatively related with temperature (r = −0.424, P < 0.05) and salinity (r = −0.613, P < 0.01). In contrast, the lowest abundances of phytoplankton (6 × 10 5 ± 1 × 10 5 cells l −1) were recorded in June, during the early monsoon due to the lowest concentration of NO 3-N (4.3 ± 0.34 µM) and PO 4-P (6.11 ± 2.99 µM). However, moderate phytoplankton abundance (20 × 10 5 ± 1.5 × 10 5 cells l −1) was found in August, during the late monsoon when the highest concentration of NO 3-N (15.7 ± 1.8 µM), PO 4-P (29.17 ± 5.15 µM), temperature (31.67 ± 0.29°C), and lower salinity (17.67 ± 1.53) was observed. This result, therefore, suggests that fluctuation of nutrients is crucial in controlling phytoplankton bloom dynamics in the Maheshkhali channel, Bay of Bengal, Bangladesh.
... Bhat & Matondkar (2004) have reported the events of harmful algal blooms from coastal waters of Tamil Nadu, Karnataka, Maharashtra, and Kerala. Among all, Trichodesmium and Noctiluca blooms have been the most frequently observed in the Indian waters (Anantharaman et al., 2010). Andaman waters indicate the blooms of N. scintillans, C. centralis, R. alata, R. imbricata, T. erythraeum, Phaeocystis sp., P. divergens and C. furca to be caused by the land runoff that was initiated by heavy rainfall, carrying high nutrient concentration into the coastal waters ( Eashwar et al., 2001;Dharani et al., 2004;Karthik et al., 2012;Arun Kumar et al., 2012;Sachithanandam et al., 2013;Karthik & Padmavati, 2014;Karthik et al., 2014a & b). ...
Chapter
An algal bloom is a rapid and prolific increase in phytoplankton biomass in freshwater, brackish water or marine water systems and is recognized by the discolouration in the water based on the phytopigments in the algal cells (either innocuous or toxic). Algae can be considered to be blooming at widely varied concentrations, reaching millions of cells per millilitre, or tens of thousands of cells per litre. Occurrence of bloom and its persistence are a complex environmental process involving multiple factors such as anthropogenic nutrient (eutrophication), solar radiation, temperature, current patterns and other associated factors. This natural but stochastic event leads to severe ecological health hazards, degradation of water quality and productivity and pelagic community structure. Proliferations of toxic microalgae in aquatic systems can cause massive fish kills, contaminate seafood with toxins and alter ecosystems in ways that humans perceive as harmful. The chapter addresses a comprehensive account regarding basic features related to algal bloom, such as Redfield ratios, eutrophication and hypoxia (deoxygenation). This is followed by detailed account of the major bloom causative agents (diatoms, dinoflagellates and cyanobacteria) and the remote sensors usually in practice for water quality monitoring. Finally a comprehensive account of the analytical instruments has been discussed generally used for microalgal studies for taxonomic and chemical component analyses.
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Present automated systems for counting and measuring marine plankton include flow cytometers and in situ plankton video recorders. Neither of these approaches are optimal for the microplankton cells which range in size from 20 to 200 mu m and can be fewer than 10(4) l(-1). We describe here an instrument designed for rapid counting, imaging and measuring of individual cells and particles in the microplankton size range from cultures and natural populations. It uses a unique optical element to extend the depth of focus of the imaging lens, allowing a sample stream flow rate of 1 ml min(-1) The instrument stores a digital image of each particle along with real time fluorescence and size measurements. An interactive cytogram links a dot-plot of the size and fluorescence data to the stored cell images, allowing rapid characterization of populations. We have tested the system on live phytoplankton cultures and bead standards, proving the system counting and sizing accuracy and precision. The system provides images and size distributions for cultures or natural marine samples. It has been used successfully at sea to continuously monitor particles while underway. It may prove useful in studies of plankton community structure, ocean optics and monitoring for harmful algal species.
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The oyster population in the Maryland portion of Chesapeake Bay, USA, has declined by more than 50-fold since the early part of this century. The paper presents evidence that the mechanical destruction of habitat and stock overfishing have been important factors in the decline, even though it is commonly thought that 'water quality' and, more recently, oyster diseases are critical. Quantitative analyses show that the long-term decline of oysters largely results from habitat loss associated with intense fishing pressure early in this century, and stock overfishing from early in the century through recent times. Furthermore, the major ecological effects on Chesapeake Bay occurred well before World War 11, before industrialization and the reported prevalence of disease. To effect the recovery of the ailing Chesapeake Bay oyster stock, a 4-point management strategy is proposed.
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The photosynthetic pigments of 12 species (14 strains) of cultured diatoms from six genera under specific conditions were examined by the HPLC. The diatom genera were Skeletonema, Thalassiosira, Chaetoceros, Nitzschia, Phaeodactylum and Meuniera. All strains were isolated from China seas and most of them were from the Jiaozhou Bay, China. Fifteen pigments were identified and eight of them were various chlorophyll a derivatives. Chlorophyll a, c2 and c1 and the carotenoids fucoxanthin, diadinoxanthin, diatoxanthin and β,β-carotene existed in all species. The ratios of each pigment to chlorophyll a were compared with the results in literatures. The pigment ratios of this study generally fall within the ranges reported by the literatures although the maximum ratio of fucoxanthin to chlorophyll a was higher and the ratios of chlorophyll c and diatoxanthin to chlorophyll a were low. The pigment ratios are useful to understanding the pigment signatures of diatoms in the Jiaozhou Bay, China, and to setting up the chemotaxonomic method ofphytoplankton in these sea areas.
Article
Large-subunit ribosomal RNA (LSU rRNA)-targeted of oligonucleotides specific for Pseudo-nitzschia ausiralis Frenguelli were Used to discriminate (hill species front cultured isolates of P. pungens (Grunow) Hasle, P. multiseries (Hasle) Hasle, P. delicatissima (PT Cleve) Heiden, P. pseudodelicatissima (Hasle) Hasle. P. fraudulenta (P.T. Cleve) Heiden, P. heimii Maguin, and P. americana (Hasle) Fryxell using whole Cell (in situ) and sandwich hybridization. Whole cell hybridization involved application Of fluorescently labelled probes to chemically preserved (intact) cells. Cells that retained the probe were visualized Using epifluorescence microscopy. In contrast, sandwich hybridization wits initiated by homogenizing live cells to liberate their contents. Detection of P. australis wits accomplished by capturing LSU rRNA from unpurified cell lysates Using a species-specific Oligonucleotide attached to a solid support. Captured molecules were washed free of other lysatc and hybridized to a biotinylated signal probe that bound more conserved regions of the molecule. The signal probe served its it platform for an enzyme-driven colourimetric reactions presence Of P. australis in the sample resulted in a macroscopic colour change of the solid support. Both whole cell and sandwich hybridization methods are Useful techniques for discriminating P. australis from its closely related congeners. The relative advantages and disadvantages of each technique are discussed. With respect to future applications, choice of one method over another will likely depend on the particular question at hand and the type of data one wishes to obtain. At present, sandwich hybridization appears faster. easier. and more amenable to automation. For these reasons, it may be a more appropriate technique for routine, rapid enumeration of potentially toxic microalgal species in large numbers of environmental samples.
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Toxin production is widespread among aquatic microalgae, suggesting a functional advantage for organisms producing toxic compounds. However, the biological role of algal toxin production is only vaguely understood. Here, we show that excretion of a toxic substance in the phagotrophic phytoflagellate Prymnesium parvum(Prym- nesiophyceae) constitutes a mechanism to immobilize and seize motile prey. Feeding frequency of P. parvum in dilute batch cultures was low when fed the motile prey Heterocapsa rotundata (dinoflagellate). However, dense cultures caused immobilization of H. rotundata cells, thereby allowing P. parvum to feed on them. In contrast, when fed a nonmotile prey—the diatom Thalassiosira pseudonana—feeding frequency was high, even in dilute P. parvum cultures. We could demonstrate that feeding frequency of P. parvum on H. rotundata was positively cor- related with the measure of the toxic effect causing immobilization and lysis of prey cells. The fact that the toxic effect on H. rotundata was found in cell-free filtrate of P. parvum cultures suggests that immobilization and lysis of prey cells were caused by the excretion of toxins. Blooms of planktonic algae are common in aquatic envi- ronments, and harmful algal blooms cause substantial com- mercial problems for the exploitation of marine and fresh- water resources, as well as for recreational purposes (e.g., Hallegraeff 1993). The harmful effects of algal blooms are typically from toxins produced by the algae. The question of why algae produce toxins has, therefore, been a point of much speculation, but few facts exist on possible biological or ecophysiological roles of toxin production. Toxins might
Article
Weekly observations over a 7-year period show that the phytoplankton of Narragansett Bay, Rhode Island, is alternately dominated, from May through October, by brief blooms of the diatom Skeletonema costatum and the flagellate OZtihodiscus Zuteus. The two species are almost never abundant simultaneously. When grown together in culture, one or the other dominates, the outcome of competition depending on the relative ages and concentrations of the inocula. Culture experiments in which each species was grown in medium conditioned by growth of the same or the other species, with nutrients restored, showed that 1) each species somewhat inhibits its own growth, 2) Skeletonema does not inhibit OZisthodiwus, and 3) Skeletonema is inhibited by high concentrations of OZ&&odis~s-conditoned medium, but is stimulated by low concentrations. It is pro- posed that OZtihodticus achieves dominance by production of large amounts of an ectocrine (of suggested tannoid nature) that inhibits Skeletonema and that Skeletonema achieves dominance primarily by virtue of its superior reproductive rate, but that in addition, in small competing populations, its growth is accelerated by the OZisthodiscus ectocrine-a stimulant in low concentrations. These mechanisms are shown to explain satisfactorily events observed in bialgal culture and are believed to be operative in nature.