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Environment and Productivity patterns of Indian EEZ
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Marine Research -Living Resources (MR-LR)
Assessment Programme
Report
Cruise 251
FORV Sagar Sampada
Study Area – Northern Arabian Sea
(29th Nov. 2006 – 20th Dec. 2006)
Participants
National Institute of Oceanography, Regional centre, Kochi
Central Marine Fisheries Research Institute, Kochi
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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LIST OF PARTICIPANTS OF CRUISE No.251 OF FORV SAGAR SAMPADA
NIO-RC, KOCHI
1. Dr. Maheswari Nair
- Chief Scientist
2. Mr. Muraleedharan K.R
- Project Assistant III
3. Mrs. Jasmine.P
- Project Assistant III
4. Mrs. Asha Devi C.R.
- Project Assistant III
5. Ms. Jayalakshmi.K.J
- Senior Research Fellow
6. Ms. Vineetha Gopinath
- Project Assistant III
7. Mr. Mathew Paul
- Project Assistant III
8. Mr. Saneesh.A.V
- Project Assistant III
CMFRI
9. Mr. Anoop.A.Krishnan
- Research Fellow
CMLRE
10. Mr. Renjan K.A.
11. Mr. sunil Kumar K.R.
- Fishing Master
- Fishing Hand
12. Mr. Pradeep Kumar
- Fishing Hand
13. Mr. Binoy V
- Fishing Hand
M/s. NPL
14. Mr. Benny.J.Panakkal
- Service Engineer
15. Mr. Mebish Mathew
- Service Engineer
16. Mr. Sumesh T.T
- Service Engineer
17. Mr.Renjith Jose
- Service Engineer
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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Objectives
Collection of data on environmental & productivity studies and Survey of
marine Mammals
Physical
1. Collection of CTD data up to 1000 m
2. Collection of Surface Met data
3. ADCP
Chemical
1. Dissolved Oxygen
2. Nutrients
Biological
1. Primary Productivity Studies
2. Secondary Productivity Studies
3. Microzooplankton studies
4. Marine mammals
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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Cruise Track – 251 (Northern Arabian Sea)
Environment and Productivity patterns of Indian EEZ
Fig.1 Map showing the Station position of cruise 251 during winter monsoon in
the Arabian Sea overlaid on bathymetric chart.
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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INTRODUCTION
The cruise 251 of FORV Sagar Sampada was focused on the study of
Environment and Productivity patterns, in the early phase of winter cooling in
the Arabian Sea (Nov. – Dec. 2006). In addition, survey of Marine Mammals was
also carried out as a part of studies conducted by Central Marine Fisheries
Research Institute. This cruise started on 29th November from Mangalore with an
aim of covering 21 stations in the northern 4 transects (21ºN, 19ºN, 17ºN and
15ºN) under MR-LR programme.
CTD was operated at all the stations and water samples from standard
depths were collected for the study of Physical, Chemical and Biological
parameters. Primary productivity studies were carried out at 7 stations by insitu
incubation (Mooring) and 1 station by deck incubation. Multiple Plankton Net
(MPN) and Bongo nets were operated at all stations to get the vertical and
transverse profile of the zooplankton abundance.
Physical Oceanography
Mr. Muraleedharan K.R and Mr. Saneesh A.V
National Institute of Oceanography, Kochi.
During the cruise 251, twenty stations were sampled in four transects. The
major objective of this cruise was to study the environmental processes in the
northern Arabian Sea during early phase of the winter monsoon. Eighty-one
CTD castings were carried out in a spatio-temporal scale and recorded raw data,
were processed with a bin average of 1m depth to an ASCII formatted output.
Mixed layer depth was calculated according to a depth at which temperature of
0.5°C drop from SST. Thermocline was taken at a depth where temperature
shows 15°C. Surface meteorological parameters including SST were measured
manually and compared with the data from automated Integrated Data
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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Acquisition Software (IDAS). The salinity values from the CTD were corrected
against the values obtained from the ship borne Autosal (Guild line 8400b).
ADCP (Acoustic Doppler Current Profiler 153 KHz) was operated throughout
the cruise and the data was recorded at a bin size of 8m according to station wise
(stationary) and station to station (running) mode.
22
India
21
1018
20
1016
Latitude (°N)
19
1014
18
17
1012
16
1010
15
10 m/s
1008
14
66
67
68
69
70
71
72
73
74
75
76
77
78
Longitude (°E)
Fig.2 showing north south variation in the barometric pressure (shaded) with an
overlay of SST (contour) and super impose by wind vectors (arrow)
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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70
Depth (m)
60
50
40
30
MLD Coastal
MLD Open
20
15
17
19
21
Latitude (°N)
Fig.3 showing mixed layer depth variation in the coastal (200m) and open ocean
area
Salient features
 Maximum Sea Surface Temperature (SST) of 29.3°C was observed at
coastal station of the Goa transect and minimum of 25.7°C was observed
off Veravel transect.
 Atmospheric Pressure (AP) showed a north - south gradient in the study
area. Lowest AP of 1009.8 mb was recorded in the southern stations and
high AP of 1017 mb was recorded at northern stations.
 North- northwesterly wind with an average speed of 5.3 m/s prevailed
over the study area.
 Shallow Mixed Layer Depth (MLD) of 29 m was observed at coastal
stations (200 m) of all transects and a deep MLD was observed at all open
ocean stations.
 Sea Surface Salinity showed maximum value of 36.62 psu in the open
ocean waters (max at northern stations) and minimum of 34.72 psu in the
coastal waters.
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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 Average humidity observed during the cruise was 61% and least humidity
was observed at Veravel and Mumbai transect.
Chemical Oceanography
Dr Maheswari Nair and Mr Mathew Paul
National Institute of Oceanography, Kochi
During the cruise 251, twenty stations were sampled in four transects. A
total of about 283 samples were colleted from standard depths (0, 10, 20, 30, 50,
75, 100, 150, 200, 300, 500, 750 and 1000 m). Samples for dissolved oxygen were
immediately fixed with Winkler A and Winkler B reagents and subsequently
analyzed onboard using titration method (Dosimat model 665) after calibration.
pH was estimated using WTW pH Meter after calibrating using buffer standards
of pH 7 and 10. Nutrients (Nitrate, Nitrite, Phosphate and Silicate) were analyzed
by using the segmented flow Auto Analyser (SKALAR) onboard after calibration
using appropriate standards and following standard procedures.
Salient features
 Dissolved Oxygen showed higher concentrations (<212 µM) in the
surface waters of all transects and this is followed by an intense
oxygen deficiency in the intermediate layers (150-1000m) with DO
concentrations as low as 5.45 µM.
 The pH values in all transect ranged from 8.40 to 7.73 with maximum
values observed in surface well mixed waters (0 to 50m) followed by
minimum values in deeper layers.
 Low concentration of nutrients was observed in the surface waters (050m) of all transects followed by an increase in the concentration at
intermediate depths reaching higher values at 1000m (nitrate~48 µM,
phosphate~4.46 µM, silicate~ 65 µM).
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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Biological Oceanography
Mrs. C.R. Ashadevi, Miss .K.J Jayalakshmi Mrs. P. Jasmine & Miss. Vineetha Gopinath
National Institute of Oceanography, Regional centre, Kochi.
Primary productivity studies
Primary productivity measurements were carried out at all transects (4), at
inshore and (4) offshore stations (total eight: 7 In - situ and 1 Deck incubation).
14C
technique was used for the productivity studies by incubating the samples
from sunrise to sunset from seven discrete depths (surface, 10, 20, 50, 75, 100 &
120 meters). After inoculating the sample with 1 ml of NaH14CO3 (activity 5 µC)
the light and dark bottles were kept for insitu incubation for 12 hrs. After filtering
the samples through 47 mm Whatman GF/F filters (0.7 µm) and the filters were
exposed to HCl fumes to remove inorganic carbon and kept in scintillation vials
(8 ml) for later isotopic analysis at the shore lab.
For the estimation of
chlorophyll a, one-litre of seawater was collected upto 75m from all stations and
upto 120m from all PP stations, was filtered through 47 mm Whatman GF/F
(with a few drops of MgCO3), and kept in the refrigerator for further analysis.
For the estimation of Particulate Organic Carbon 1 litre of seawater (seven
depths) was filtered from all the PP staions and the filters were stored in freezer
till its analysis in shore lab.
Collection of Phytoplankton
250 ml of seawater was collected from each of the 7 depths at the PP
stations using CTD rosette sampler and preserved in Lugol’s Iodine solution. The
qualitative and quantitative study of the Phytoplankton will be carried out at the
shore lab.
Collection of Microzooplankton
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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8 litre of seawater was collected using CTD from the 7 depths at each of
the PP stations and sieved through 20 µm mesh and preserved in Lugol’s iodine
solution, to be analysed at the shore laboratory.
Secondary productivity studies
Zooplankton samples were collected from all stations by using Multiple
Plankton Closing Net (Hydro bios) and Bongo Net.
Bongo net was operated horizontally for 10 minutes at 2 knots ship speed
at all stations for the collection of zooplankton especially for fish eggs and larvae.
After the measurement of live biomass, zooplankton samples were preserved in
4% formalin-seawater.
MPN (mesh size 200 micron and mouth area 0.25 m2) was used for the
stratified sampling of zooplankton from five different standard water columns
(0 – TT, TT – BT, BT – 300, 300 – 500 and 500 – 1000m). The hauling speed of
MPN was limited to one meter per second. After the measurement of live
biomass, the zooplankton samples were preserved in 4 % formalin-seawater.
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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Biomass (ml/m-3)
22
21
20
Latitude (°N)
19
18
17
16
15
14
66
67
68
69
70
71
72
73
74
75
76
77
78
Longitude (°E)
Fig.4 showing the mesozooplankton biomass (ml.m-3) in the mixed layer of
Northern Arabian Sea during the cruise.
Salient features
 Highest mesozooplankton biomass was observed in the mixed layer of the
offshore stations than the coastal stations.
 In the offshore regions maximum biomass (1.33ml.m-3) was observed at
21°N 67°E ( Stn. 1928 B).
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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 Among the coastal stations, the maximum biomass (0.73ml.m -3) was
observed at 21°N & 69°E (Stn. 1926) followed by coastal station (Stn. 1921)
of 19° N
 The lowest biomass (0.109ml.m-3) was seen at the coastal station of 15°N
(Stn. 1911B)
 Northern transects (21° and 19°N ) showed high mesozooplankton
biomass than the southern transects (15 and 17°N)
Issac - Kidd Mid water Trawl operation
IKMT was operated at offshore stations of 15° and 17°N transects. The
operation was carried out for 30 minutes duration with a ship speed of 2 knots.
Major composition of the sample was eel larvae (11 ml.m-3) and euphausiids
(7ml.m-3).
Marine mammals observation
ANOOP. A. KRISHNAN
RESEARCH FELLOW, CMFRI.
The study on the geographical distribution of cetaceans is taken as an
objective during the present Cruise 251 along the west coast of India. As a part
of survey on cetaceans following work were carried out.
 Sightings and photography of whales, dolphins and porpoises.
 Recording of hydrographical and meteorological data’s from the region of
cetaceans sightings.
Studies were carried along the west coast of India (Arabian Sea) from
Mangalore to Veravel and back to Kochi. Continuous watch (6.00 – 18.00 hrs) of
cetaceans was carried out mainly from the bridge of the vessel. A binocular and
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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Nikon F 80 wide angle zoom camera were employed to observe and capture
appearance of cetaceans in the form of spouts, dorsal fin, upper body, flipper,
flukes and body coloration whenever possible. Only if the species of a whale or
dolphin is unmistakably identified based on the reported description, its name is
recorded.
In case there was a doubt the species name was mentioned,
accompanied by “possible”. All others were treated as “unidentified”. Exact
location of cetacean sighted along with the general hydrographical (CTD) and
meteorological data (AWS) and a detailed description (to the possible extent)
along with the numbers were recorded. With the help of these data, the species
identity could be ratified in the future.
A total of 90 dolphins were sighted in the area between 10°N to 21° N
latitude and 66° to 74° E longitudes during the present cruise. Altogether 6
sightings were done and 94% of the sighted cetaceans could be unmistakably
“identified”, while the remaining was “unidentified”. Photos have been taken
wherever possible and would certainly lead to identification up to genus or
species level once other expertise are sought for ratification based on detailed
description. Around 99% of the sighted cetaceans were dolphins while remaining
was whales. The species that were identified in the cruise were (identified)
Stenella longirostris (Spinner dolphin) and (possible) Delphinus delphis (Common
dolphin). The whale sighted off Goa could not be identified.
During this cruise abundance of deep Ocean dolphins were prominent mostly off
Ratnagiri. As the survey was mostly along deeper waters the cetacean
distribution was scanty.
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Preliminary report of Cruise 251
Environment and Productivity patterns of Indian EEZ
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Fig. 5 Distribution of Marine mammals during cruise 251
Acknowledgements
The chief scientist and the scientific team of cruise No. 251 are highly
indebted to the Master Y Poojary and the crew of FORV Sagar Sampada for their
cooperation rendered through out the cruise. Words of indebtedness are also due
to the Fishing Master Mr. K.A Renjan and his associates, for their round the clock
service rendered during the sampling operation. The technical support given by
the Service Engineers of Norinco Pvt Ltd, Cochin is gratefully acknowledged.
Chief Scientist
Cruise 251
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Preliminary report of Cruise 251