“ Analysis and Identification of biological production of Dimethyl Sulphide(DMS) andDimethyl Sulponiopropionate(DMSP) by Phytoplankton in the Cochin Estuarine System (CES)”

Dayala V.T, Akhil P.S, Sujatha C.H*Department of Chemical Oceanography,Cochin University of Science and Technology,Kerala,India.

*E-mail: drchsujatha@yahoo.co.in

ICES CM2010/L:24

The present Scenario is facing a severe threat in the form of climatic variability. Most of the earth is covered by oceans and hence these play a pivotal role in controlling the climate. Studies have been proved to the fact that the tiny phytoplankton residing in the ocean can c o n t r o l t h e c l i m a t e b y production of clouds. These species emit dimethyl sulphide to the atmosphere which undergoes series of reactions and ends with the formation of sulphate aerosols, thereby reflecting sunlight .Thus DMS is inevitably the cloud creator and global coolant.

MATERIAL AND METHODSINTRODUCTION

Fifteen different stations in the Cochin estuary were taken into account.

Water samples were collected.

Identification of phytoplankton’s were done using microscope.

Macro and micro nutrient analysis were extensively detected.

The general hydrographical parameters were measured.

SAMPLING SITES

760 17.744’E 14

760 17.906’E 15

760 17.049’E 13

760 16.924’E12

760 16.043’E 11

760 15.789’E 10

760 16.084’E 9

760 16.919’E 8

760 18.253’E 7

760 18.409’E 6

760 21.430’E 5

760 23.359’E4

760 24.019’E 3

760 24.607’E 2

760 25.708’E 1

Longitude

760 17.744’E 14

760 17.906’E 15

760 17.049’E 13

760 16.924’E12

760 16.043’E 11

760 15.789’E 10

760 16.084’E 9

760 16.919’E 8

760 18.253’E 7

760 18.409’E 6

760 21.430’E 5

760 23.359’E4

760 24.019’E 3

760 24.607’E 2

760 25.708’E 1

LatitudeStations

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

9

0 05.502’N 0 04.993’N

0 05.656’N

0 03.999’N

0 03.255’N

0 01.857’N

0 59.213’N

0 57.77’N

0 55.070’N

0 53.105’N

0 49.793’N

0 49.508’N

0 48.495’N

0 47.887’N

0 47.646’N

0 05.502’N 0 04.993’N

0 05.656’N

0 03.999’N

0 03.255’N

0 01.857’N

0 59.213’N

0 57.77’N

0 55.070’N

0 53.105’N

0 49.793’N

0 49.508’N

0 48.495’N

0 47.887’N

0 47.646’N

DMS PRODUCING PHYTOPLANKTONS IN THE CES FLOWCHART

Salinity

0.000

10.000

20.000

30.000

40.000

50.000

60.000

S1

S3

S5

S7

S9

S11

S13

S15

B2

B4

B6

B8

B10

B12

B14

Stations

PS

U

Post Monsoon

Pre Monsoon

Monsoon

Concentration of Iron

0

0.5

1

1.5

2

2.5

3

3.5

S1s

S4s

S7s

S10s

S13s

B1

B4

B7

B11

B14

Stations

Co

nc

en

tra

tio

n(m

g/l

)

Post Monsoon

Pre Monsoon

Monsoon

GRAPHICAL REPRESENTATION

RESULT AND DISCUSSIONProrocentrum minimum, Skeletonema costatum, Heterocapsatriquetra, Scrippsiella trochoidea, Prorocentrum micans, Thalassiosira weissflogii these are the DMS producing phytoplankton species found in Cochin estuary.

The station no: 7 is highly populated with the above species, especially in the premonsoon season.

The concentration of iron was rich in station no: 7 in the premonsoon season.

CONCLUSIONThe marine micro algae in the niche play a vital role in regulating the climate by participating in the global sulphur cycle.

The high abundance of DMS producing phytoplankton in selected sampling sites has enriched its studies.

Positive correlation between DMS and Salinity were reported and further study in this area strengthens the justification of the above trend.

REFERENCE

D. M. Shenoy et al (2006) “Spatial variations of DMS, DMSP and phytoplankton in the Bay of Bengal during the summer monsoon 2001” Marine Environmental Research62: 83-97

Sciare J et al (2002) “ Spatial & Temporal variability of dissolved sulfur compounds in European estuaries” Biogeochemistry 59:121-141.

Stefels J (2000) “Physiological aspects of the production and conversion of DMSP in marine algae and higher plants” Journal of Sea Research 43:183-197