Hydrographical and biological parameters of Thana Creek and Bombay Harbour were studied to assess the prevailing water quality. Zooplankton samples were collected from various stations during January 1975 to July 1975. The qualitative distribution of zooplankton was found to be very irregular and fluctuating. Copepods were the dominant taxa followed by lucifers, chaetognaths, decapod larvae, ctenophores, hydromedusae, fish larvae and polychaetes. To a certain extent the distribution of zooplankton is affected by variation in salinity during different seasons, also along the length of the creek. Pronounced effect of pollution on zooplankton biomass was also observed

Desai, B.N.

Gajbhiye, S.N.

Jiyalal Ram, M.

Aquatic Commons

ZOOPLANKTON POPULATION IN THE POLLUTED 
ENVIRONMENT OF THANA CREEK & BOMBAY HARBOUR 
B. N. Desai, S. N. Gajbhiye~ & Jiyalal Ram 
National Institute of Oceanography 
Regional Centre, ''Sea Shell" 
Versova, Bombay-400 061. 
ABSTRACT 
Hydrographical and biological parameters of Thana Creek & Bombay Harbomr 
were studied to ass·ess the prevailing water quality. Zooplankton samples were 
collected from various stations during January 1975 to July 1975. The qualitative 
distribution of zooplankton was found to be very irregular and fluctuating. 
Copepods were the dominant taxa followed by lucifers, chaetognaths, decapod 
larvae, ctenophores, hydromedusae, fish larvae 
th~ distribution of zooplankton is affected by 
seasons, also along the 1ength of the creek. 
zooplankton biomass was also observed. 
& polychaetes. To a certain extent 
variation in ~ty during different~ 
Pronounoed effect of poll.'ution on 
INTRODUCTION 
Much concern has been shown m recent years on the growing problem 
of marine environmentarl pollution particularly of coastal areas which are 
becoming more useful to man's growing activities. The changes on the ecology 
of marine envi,ronment on the coastal areas of India is increasingly felt in 
recent years. Bombay is an tapt example of this. 1t has a population of about 
8.2 million and is tht largest metropolitan city on the west coast of India. 
Almost 30o/o of the countty's industries are located in this dty & near by 
area. Discharge of large quantity of domestic and industrial waste is believed 
to be changing the ecological balance of the coast: (Desai 1971, Gajbhiye 
1979). It was therefore, cons!.dered desirable to investigate the hydrobiological 
parameters and to study the water quality around Bobmay specially Thana 
creek & Harbour complex. Zooplankt-on was taken as an indicative parameter 
to assess the intensity of pollution 
46 
N 
t 
~ Llrt"" l 
3CAU• 
• 1S 
.. • • • ]II '29 )Q )I 
• • . • 32 33 Jt: )) 
Fig. 1 Map showing the location of stations. 
DESCRIPTION AND HYDROGRAPHY OF' AREA 
Bombay located at 18°55N lat. ancl 72°49 E lang is the largest dty 
on the central west coast of India. Tlie Thana creek region extends over a 
distance of 40 km in length and coveres an area of 340 km2. The creek 
is 16km lang ;and very narrow and shallow compared to the Bombay harbour 
region (Fig. 1). The Thana creek is o:::mnected to the Ulhas river on one 
side and Bombay harbour to the other side. Numerous inlets joint the Thana 
creek. During thtt monsoon these inlets discharge drainage water from different 
47 
Table - 1. VARIATION OF ENVIRONMENTAL FACTORS IN THE THANA CREEK 
AND BOMBAY HARBOUR DURING PREMONSOON PERIOD JANUARY 
TO APRIL 1975 
Sm. N.o. 
1. 
2. 
3. 
4. 
5. 
6. 
'L 
8. 
9. 
10. 
11. 
12. 
13. 
14. 
15 . 
16. 
17 
18. 
19. 
20 
21. 
22-
23. 
·z4. 
25. 
26. 
27. 
28. 
Water Temp ec 
23.6-30.5 
24.0-30.0 
24.0-30.5 
24.4-28.0 
23.5-27.1 
23:3-27.0 
23.5-27.3 
24.0-26.6 
24.1-27.7 
23.4-28.0 
24.1-28.5 
23.6-28.0 
24.5-27.5 
23.2-27.4 
23.5-26.8 
24.0-27.1 
24.8-28.5 
24.0-27.7 
24.1-27.9 
24.0-27.0 
24.0-27.0 
23.6-28.0 
23.5-27.5 
24.0-27.9 
24.0-27.3 
24.1-28.3 
24.0-27.0 
23.5-28.0 
Salin.ity Oc;to 
37.03-37.21 
37.03-37. 15 
37.15-37.36 
37.06-37.13 
36.10-37.12 
'36. 47-36.95 
35.76-36. 90 
35.59-38.95 
35.70-37.20 
35. 95-36. 70 
35.60-36. 60 
35. 0-36.60 
36.13-37.63 
35.95-37.03 
35. 89-36. 26 
35.77-36.88 
36. 13-37.03 
36.17-36.70 
35.59-37.40 
35.05-36.13 
35.37-37.00 
34.69-37.30 
36.60-37.21 
35. 95-36. 38 
35.98-37.40 
35.95-37.00 
35.95-37.30 
35.95-37.10 
Dissolved 
oxygen (m1/1) 
2.51-4.80 
3. 63-4.00 
3. 65-4.05 
4.16-4.51 
5. 02-9.14 
3. 20-5. 12 
3. 43-5 .. 01 
4.57-10.8 
2. 74-2.77 
4.61.5.12 
3.58-5.71 
2. 74-5.49 
4.11-4.27 
4.57-5.49 
1.17.3.38 
3.66-6.67 
4. 39-5.71 
3.20-7.25 
4.48-4.80 
3. 84-7.62 
1. 11-6.37 
4. 81-5.59 
4. 0-12.00 
2. 97-5.23 
4. 80-8.74 
4. 27-5.71 
1. 00-5.94 
4.69-10.37 
P04 ug atjl 
(). 73-0ti. 67 
1.11-05.67 
1.11-05.77 
1.11-03.58 
1.11-05 .~8 
0.33-03.67 
1. 11-12. 77 
0. 73~04. 00 
0. 73~03 .58 
0. 33-02.44 
0. 33-02.44 
1. 11-05.67 
0. 33-04.80 
0. 23-02.78 
1. 11-01.56 
0. 73-03.35 
0. 33-03.58 
0. 73-2.16 
1. 11-3.22 
0.34-3.18 
0. 73-2.78 
0. 34-2.44 
0. 73-1.93 
0. 73-1.93 
0. 34-1.56 
0. 33-1.93 
0.33-2.36 
0. 33-2.78 
N03 ug at/1 
16.76-49.23 
06.40-49.63 
05 . 8:1-45 . 34 
06. 99-57. 79 
13.09-57.44 
15. 13-57.97 
12.51-57.40 
05 . 24-57. 97 
16.25-58.20 
15.71-29.65 
08.44-28. 52 
08. 15-46. 69 
05 . 29-66. 09 
05.05-38.41 
07.57-28.10 
15.71-28.87 
05.53-34.92 
14.08-36.38 
10.47-22.95 
04.07-38.70 
05.09-23.86 
05.06-24.61 
06.69-19.60 
02.74-15.86 
05 09-23.86 
03.01-13.86 
03. 78-25. 72 
02.17-21.55 
area of the city but also used as a convenient &Duree of drainage for dj,posal. 
of effluent by the industries clustered around. 
The tides in this regi.on are of semi diurnal type with ·an average tidal 
range of 3. 7 m. The currents i.n the creek are 2 knots. During tb.e cold 
months December ta February the water tennperature is. relatively low 
ranging from 21.°C ta23.°C and in £ummer it goes up to 28.°C-30.°C 
(Table - 1) . During the prernonsoon months variation in salinity values 
<Ire of very small range (34o/oo - 38l*;o). High salinity values were 
normally observed along the shallow <egion close to the mud flats aod 
mangroves which may be sweeping out high saline water. However, during 
the monsoon the large amount of fresrwatcr from Ulhas river and from 
numerous inlets h)wer the salinity of the (.'teek water to about 9.60o/oo near 
tile Tlunc b idge. The D. 0. values varied from 0.17 to 12mjl. 
Phosphate value was around 5 ug at/l. A higher concentration of P04 - P 
was observed in the are:t where a low D.O. was noticed. High concentration 
of nitrate in the head of the creek ranging from 23.28 - 34.92 ug atjl 
was reported (NIO Reports 1975). 
:J\tlATERIAL AND METHODS 
The survey was planned for 1a period of two ye~rs commencing from 
December 197 4. This paper presents the data dunn,g the premmuoon 
8eason which is the most impo_ tant from the puin1 of view of the effect of 
undiluted pollutant on envir.onmental ecology. Sampling stations were 
fixed on a closer gr:d of 2 kms. CollectiOns were. made at alternate spring 
and neap conditions in e1:1ch month. Samples for hydrographical parametera 
were c:olkcted either with reversing bottles or Van Doro s;~ mpler. The 
surf~.ce temperJ.ture ·was measured with ordinary thermometer and bottom 
temperature wirh reversing thermometers. 
Plankton samples were collected with H. T. net of a mouth area of 
. 25 m2 and nu·4sh size 0. 2 mm. Horizontal hauls of 10 minutes duration 
were taken for all collections. The samples were preserved in 5i7'o neutral 
formalin. The total volume of zooplankton from each haul was determined 
by diSplacement method and biomass was calculated per 100 ro3. Sampl~ 
49 
were fractLoned by plankton splitter and the number and percentage com-
position Qf the organisms were determined. 
RESULTS 
Tt>ital zooplankton biomass varied from 1.5 rn.IIIOO ms to 2'5.0 mlf 
100 Il.ls at different .stations. The lowest value was recorded at st. 18( 1. 5ml fi 
100 m3.) Taxawise distribution was also not reg~lar. Average biomass of 
zooplankton and percentage composition are given in Fig. 2 and Fjg 3 A & B 
Copepods were dominant in the majority of samples. 
"" E 
§ 
.... 
i 
., 
., 
I 
Fig. 2 
-Biomass 
G2Si 6904 
9-, p-~~-osrso sooo I : '~ I 
'I I 
I I I 
I l I 
I I I 1.000 '1 I I I 
• 
' 
I ~ I I I t I , I I I' 
I I 3000 ~ I 
"' I I I I ! I l I 
' I I I ::> 
I I I z 
I I I 
I I 2000 I I I I I 
I I 
I r 
lj 
"· 
10001 
a 
4 s 7 8 10 u 12 18 21 2t. 2'> 26 JQ . 
THANA CAU1t 80Mf' ,6.'1' HARBOUR 
PIG. 2 
V arlation in the mean values of tot~l pop~ation and biomass of 
zooplankton in the thana cmek & bombay Harbour. 
Different groups observed in the zoopM,nkton sap1ples collected from 
various stations were flagellates, medusae, siphnophores, ctenophores, poly-
chates, chaetognaths, cop~pods, decapods larvae, amphipods, lucifers, mysids 
fish eggs aq.d fish larvae. Besides these ostracods and gastropods, appeared in 
a few •umbers. 
50 
STN.' 
LO 
30 
~0 
10 
STN 7 
10 
STN. 10 
STN 1/ 
i.O 
)0 
29 
lQ 
Fig. 3a 
Bi 
~ ~ i i .. 
' 
~ 
&6 
"' ;! 
" ~
; 
Percentage composition 
sele,cted stations. 
STN. ~ 
~ 
13, e: :rl 
1.0 
-30 m 
20 B 
10 t•••l 
STN 6 
l.fJ 
30 
"" 
20 I 
... 
10 I 
II 
sm 11 
LO 
30 
20 
10 
STN. 18 
t.O 
30 
20 
10 
of different groups of 
51 
C~t,.eds 
OtC:lljiUidS 
Chul&pths 
Ftsh tog t 
Larva. 
MHu.sn 
lvctltf Sp. 
"' 
"' I I l. I 0 .. 
" ~ "' ! ... ... 
., 
... ... 
"' ! 0 "' I ~ .. l , ·~ 0 0 ~ :r 
o: >- ~ v; v 
" 
zooplankton at 
STN .. 2l STN. 2l. 
. STN. 26 STN. )0 
<.0 
)0 
"' "' 
"' .. 
... 
! Q 20 f ... ~ ~ 
' 
~ ... 
r ... I (l. 0 ~ ~ ~ .. .. ~ ... 2 10 ... ! z .. ~ x: 
"' 
:> ,. 
I? " 
X wJ G .. ... 3 r ~ ... 3 "' .. -, .. v, 
" 
G: ... 
fiG. 3 6 
PerceDltage composition of different groups of zooplankton at 
selected s~tations. 
Medusae 
The highesf number of medusae were observed at ·st. 5 (7. 520"o) and 
the lowest density was recorded at St. 20 (0.08o/o). They were not 
noticed at stations 4, 7, 12, 18, 21, 24 and 26. The dominant species 
belonged to the genera Phi.alidium> Eirene~ and Blackfona'ia. 
Siphlmophores 
They w:ere · observed rarely at a few stations. The highest number of 
siphonop•hores were observed at st. 26 (1 .12o/o) in the month of March. 
Ctenophores 
They were observ-ed at six 
dominant SP. of Pleurobrachia 
observed at St. 18 (13 . 21 o/o) 
observed at St. 30 · ( 0. 07o/o). 
different stations in large number with the 
The highest number of ctenophores were 
in the month of February and lowest were 
52 
Polychaetes 
Large number of polychaetes were observed in the sample collected at 
st. 10 jn Japuary. The lowest ·number of polychaetes were f·:::mnd at st. 25 
in March. At St. 4, 5, 7, 8, 12~ 18; 21 and 26 they were not observed. 
The recorded species belong to the genus Tompop.etris. 
C hate tognaths 
Chaetognaths were observed in almost all samples excepting st. 5 and 
12 . Maxim urn population ( 14 . 99o/o) was ·observed in January. The lowest 
number of chaetognaths were found at St. 25 in March. The dominant 
species were S. bedoti and S. enflata. 
Copepods 
They were dominant m the majority of samp~es except in the samples 
collected from St. 12, 24 & 25 where lucifers and flagellates were dominant. 
The number of copepods in the harbour area was higher than that of the 
creek area. The highest number of copepods were observed at St. 26 in 
March 8160/100 m3 and the lowest found at st. 25 (1.33o/o) where the 
N octduca bloom was observed. 
of genus Acartia, Paracalanus, 
Eucalanu·. 
DECAPODS LARVAE 
The copepods were represented by species 
Acrocalanus, Oitlwna, Centrophages & 
Ex,cept St. 7 and 24, they were observed in all samples anJ their· inci-
dence varied between 0. 04o/o to 29. 5o/o. At st. 21 they formed the second 
abundant group in March (about 29. 5o/o) . The decapods were represented 
mainly by zoea, protozoea and other stages of larvae. 
Lucifers dominated the sampLe at statk:m 18 and 24 in February 19'75 
with a v,alue of about 66. 46<1o and 44. 03o/o respectively. The lowest 
number of lucifers were observed at st. 25 ( 0. 15o/o) in March. 
53 
More fish eggs and larvae were observed in the creek area. The 
highest number of fish eggs were observed at st. 10 in January and the fish 
farvae were observed at st. 11 in February. The . lowest number of fish 
eggs and larvae were observed in the harbour area i, e. 0, 005<1o at station 
25 and 0. 16o/o at station 24 . 
DISCUSSION 
The results have indicated that the average production of zooplankton 
Is very irregular & fluctuating in Thana creek and harbour oomplex. The 
Thana creek is connected ro the Uihas river on one side and Bombay Harbour 
on the other side. It is also characterised by high saline water during the 
dry months between 'October to May and very hw saline water between Juee 
~to October. (Zingde et al 1979) & (NIO Report 1975) . It exhibits salinity 
g.radient 1along its. length from the harbour mouth to the Ulhas on the otller 
side. 
Almost 1/3 of the country s industries are located in this region which 
discharge effluents in the upper reaches of the Thana creek. Domestic 
sewage is al&-~ discharged from Bombay, Tharia and other adjoining suburbs. 
Desai (1971) has reported marine pollution and disposal of sewage around 
Bombay. 
Zooplankton like any other living p·~pulation, are generally affected by 
the environmental conditions like temperature, salinity, dissolved oxygen 
etc. Also, the changes brought ab-~ut by the introduction of vadous type 
of waste may bring about significant differences in zooplankton population .. 
The average biomass is ranging from 1.5 to 25.0 mi,flCO m& 
which is considerably low compared .t,o the unpolluted regions of the we:s:.t 
coast of India. (Paulinose & Aravindakshan 1977, Menon and Geotge 1977). 
Although some stations represent normal vaiues. Stations along the length of 
the creek where the industrial effluents are discharged i.e. the stations 7, 
10 and 18 have been adversely affected. __ Zooplankton production is how.-
ever, higher in the station near the head of the creek and the harbour on the 
other side (Fig 2). The average maximum values were recorded in the 
month of March & April coinciding with one of the peak period& of 
54 
zooplankton production. A bimodal peak in zooplankt·m1 abundance in 
Bombay waters has been reported by Pillai (1968), and Gajbbiye (1979). 
Tht predominance of cupepods was noticed many times during the highest 
population density peak recorded at sts. 11, 30 & 8. Acartia & Paracalamts 
were the deminant gen~.ra in these samples. The cmnmon .copepods 
of Bnmbay have ~already been reported by many previous workers in different 
periods. ( Sreenivasan 1942 & Pillai 1968). chaetognaths wen:. represent-
ed by S. bedoti at Thana creek and S. bedoti & S. born!Jayensis at Harbour. 
The other common group was hydromcdusae which was represented by the 
g;;nera phia/Jidium, Eirene and Blackfordia at Thana and 
Phialid'ium.. Black.fordia, Eutima and SolumundeNa h1 the 
harbour. The dominance of medusae and ctenophores in Thana .is significant. 
Choprq ( 1960) noticed a sudden outburst of ctenophores al·ong with medusae 
in Bombay wateL Lucifers, polychat larvae, were l1lso present in good 
numbers whereas larvae & gastropods \'\'ere very poor. 
Parameters like low DO, high BOD and very high nutrient values as 
revealed can be very wdJ ~attributed , to the poHutional condil.ions due to 
disch~trge .nf large amount of industrial effluent from Thana. Comparison of 
the result obtained during the present study on ithe distribution and abundllilce 
of zooplankton with those of Gae (1934), BaJ & Pradhan (1945, 1952) 
and Pillai ( 1968) clearly indicated the changes brought about by the adverse 
effect of iltd scrimluate discharge of pollut~;<nt in 1:0 the creek 
ACKNOWLEDGEMENT 
The authors are thankful to Dr. S. Z. Qasim Director Na.tional InstitUte 
uf Oceanography, for his keen interest the work and crit:cal comments on 
the manuscript. We are grateful to Dr. (Mrs) Vijayalakshmi R. Nair for 
cri:tical and constructive comments on this manuscript. vVe wish to thank all 
of our colleagues for tl1~ir assistance in the field work. 
REFERENCES 
B 1 D \ ' d ·p dl•·• L.B'. 194-". a , . . . an ra ...<.n .• 
Plankton of Bombay Harbour Curr. Sci 14(8) 
55 
A preliminary note on th.e 
111·212. 
Bal, D. V. and Pradhan, L. B. 195 2. Records of Zooplankton in 
Bombay waters during 1944-47. J. Univ. Bombay, B 20 : 72-80. 
:Belsare, S. G. Mhaswade, D. M. and GOIIe, P. S. 1975 Observations on 
the plankton and Hydrological features. J. Bio[. Sci. 18 11-21. 
Chopra, S. 1960. A note on the sudden outburst~ of ctenophores and 
medusae in the waters off Bombay, Curr. Sai. 27 : '392-393. 
Desai B. N. 1971. Disposal of sewage and marine pollution mountl 
Bombay (Abstraet) Bull. N.J.S). 
Gae Piroja B. 1934. A thesis on a contribution to the study of the 
macroplankton of the Bombay Harbour. M.Sc. Thesis submitted to 
Bombay University. 
Gajbhiye S. N. 1979. Compar.,.at: ve study of zo-::>plankton population 
from unpolluted and polluted waters around Bombay. M.Sc. thesis 
submitted to Bombay University. 
Menon M. Devidas and George K. C. 1977. On the abundance of 
zooplankton along the southwest coast of India during the year 1971-7 5. 
Proc. Symp. Warm. Water oopl. Sp. Pub. NIO Goa} 205-213. 
N. I. 0. Report 1975. Pollution study of Thana creek & Bombay 
Harbour - sponsored by MWPB. 
Paplinose. V. T. and Aravindak~1an, 1977. Z8oplankton biomass 
abundance and distribution in the north and northeelstern Ar1abian sea. 
Proc. Symp. Warm Water zoopl. Sp. Pub. N1.t. lnst. NJO} Goa 132-136. 
Pillai V. K. 1968. Observations on the plankton off Bombay coast 
with remarks on the hydrographic condition and .fishery. J. mar. biol. 
Ass. India. 10(2) 237-244. 
Sreenivasan, H. M. 1942. Study on the copepods of Bombay Harbour. 
M.Cc. thesis submitted to Bombay University. 
Zi.ngde M.D. Trivedi S. K. & Desai B. N. 1979. Physico-chemical 
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56 


Zooplankton population in the polluted environment of Thana Creek and Bombay Harbour

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Zooplankton population in the polluted environment of Thana Creek and Bombay Harbour

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