Results of bottom trawling in inshore areas off Paradeep with reference to total catch composition and catch per unit effort during 1962-1978 are reported. With increase in fishing effort, benthic species recorded the highest catch in 1969-'70 and thereafter it fluctuated. Fluctuations till 1968-'69 may be due to seasonal migration of fishes. The decline after 1971-'72 can be attributed to overfishing. Off Mahanadi, Devi and Rushikulya river mouths, showed a north-south migration of fishes from october. Presently off Devi river mouth is a rich ground for demersal fishes

Biswas, K.P.

Aquatic Commons

Fish. Techno!. (1979) 16, 101-107 101 
Inshore emersal Fisheries off rissa. oa.st 
K. P. BISWAS':' 
Co-ordinated Research Project on Utilisation of Trash Fish, Kujang, Paradeep 
Results of bottom trawling in inshore areas off Paradeep with reference to total 
catch composition and catch per unit effort during 1962-1978 are reported. With 
increase in fishing effort, benthic species recorded the highest catch in 1969-'70 and 
thereafter it fluctuated. Fluctuations till 1968-'69 may be due to seasonal migra-
tion of fishes. The decline after 1971-'72 can be attributed to overfishing. Off 
Mahanadi, Devi and Rushikulya river mouths, showed a north-south migration of 
fishes from Octo bel'. Presently off Devi river mouth is a rich ground for demersal 
fishes. 
Orissa has 480 km of coast line. The 
broad continental shelf in the northern 
region extends from 25 to 35 km and is a 
rich ground for pelagic fishes (Roy & Roy, 
1972). The continental shelf narrows 
towards south (Borisov, 1962) and is a 
favourable trawling ground for pelagic and 
demersal fishes. Even though trawling 
started in 1962 at Paradeep (Biswas, 1978) 
attempts to evaluate demersal fishery reso-
urces have not been made so far. The 
present communication based on catch 
per unit effort (Bane1ji & Krishnan, 1973) 
attempts to evaluate the demersal fish 
stock off Paradeep. 
Materials and Methods 
Bottom trawlings were conducted at 
Paradeep (Lat. 20°15' N, Long. 86°45' E) 
off Astarang (Lat. 20°N, Long. 86°23' E) 
and off Damodarpur (Lat. 19°25' N, 
Long. 85°5' E) situated on Mahanadi, Devi 
and Rushikulya river mouths (Fig. 1). 
Wooden trawlers of 9.75 to 13.1 m OAL 
fitted with 55 to 90 B.H.P. engines were 
employed. Otter trawls with 18 to 23 m 
head rope and 2.5 em stretched cod-end 
mesh were operated between Mahanadi 
and Jatadhar river mouths (Fig. 2) at 6 to 
15 fathoms during October to March from 
0700 h to 1600 h. Duration of each haul 
varied from 90 to 120 min. Monthly and 
yearly variations in catch and its composi-
tion were recorded for prawns, pomfrets, 
*Present address: Orissa Maritime and Chilka Area 
Development Corporation Ltd., Bhubaneswar-3 
Vol. 16 
clupeiform fishes, polynemids, sciaenids, 
tibbon fishes, silver bellies, glass fishes and 
cat fishes. The rest are grouped as mis-
cellaneous. The meteorological conditions 
were similar to that reported by Biswas 
(1978). Since data pertaining to the effi-
ciency of nets, fishing techniques and catch 
were available, the actual fishing perfor-
mance of steel trawlers alone were evaluated. 
In wooden trawlers, the fishing efficiency 
varied with reference to design, size, mater-
ial and ownership of nets and hence data 
collected by government trawlers were 
taken as the basis. In case of private 
trawlers, the efficiency was calculated by 
random sampling. 
uo' 
.,· 
•o' 
10 
'--"'--/---------'---------'"' 
Fig. 1. Location of fishing base 
102 
Results and Discussion 
The total landings from 1962-'78 
(Table 1) indicate a maximum of 3,088.92 
tonnes during 1975-'76 employing 25 tra-
wlers. As the effort varied with the size 
of the boat, engine horse power, size of 
nets, and period of the year, the catch per 
trawling hour was taken as the index. The 
total catch per trawling hour was 126.30 kg 
during 1962-'63 (Table 3). It fluctuated 
during subsequent years with the highest 
in 1969-'70 (221.88 kg/h). The catch/h 
was lowest in 1976-77 (27.40 kg/h). Ins-
pite of fewer boats (4 to 19) operated during 
1962-'63 to 1970-'71, the catch per unit 
2() 
·o 
"' .. .. 
"' 
' 
' 
' 
---
---
/ 
I 
I 
'- -
Fig. 2. Trawling ground between Mahanadi and 
Jatadhar 
effort was nearly 2.5 to 8.0 times more 
than that of 1976-'77. But in 1977-'78, 
with 5 boats covering 4572 trawling hours 
(Table 2), the catch rate was only 43.89 kg. 
It was 126.3 kg/h in 1962-'63, 67.61 kg/h 
in 1964-'65 and 81.2 kg/h in 1967-'68 even 
though the fishing effort in those years 
never exceeded 3886 trawling hours. A 
substantial increase in fishing effort during 
1971-'72 to 1976-'77 failed to increase the 
catch rate proportionately (Table 3). 
From 1962-'63 to 1967-'68, only govern-
ment trawlers were engaged in fishing. 
From 1968-'69 onwards, private trawlers 
started fishing, reaching a maximum of 25 
boats in 1975-'76. Consequently, there was 
K. P. BISWAS 
a sudden increase in the fishing effort 
(37,396 trawling hours) and catch rate (82.60 
kg/g) as shown in Fig. 3. With further 
increase in fishing effort (81,476 
trawling hours) in 1976-77, total catch rate 
lowered significantly (27.40 kg/h), indica-
ting the attainment of maximum sustainable 
yield as observed by Gulland (1968). In 
1977-'78, by reducing the fishing effort, the 
catch per hour increased only marginally 
(43.89 kg/h), suggesting that the increased 
fishing effort in 1976-'77 completely explo-
ited the fishes in the area and the migration 
of fishes could not replenish the stock to 
the earlier level. According to Bane1ji & 
Krishnan (1973), when both the catch and 
catch per unit effort in a steady population 
shows a downward trend, it can be con-
cluded that the increased fishing activities 
result in a reduction of the yield, and the 
fishing effort has to be reduced. 
To obtain a measure of the activity 
of the fishing fleet, estimates for the total 
trawling hours with catch, percentage of 
total trawling hours without catch, trawling 
hours with catch per boat and total boat 
days availed in the season (Table 2) were 
made. The first estimate of total fishing 
effort of steel trawlers was obtained by 
adding trawling hours with catch and esti-
mated trawling hours without catch per 
year. The second estimate was arrived at 
by multiplying boat days and average tra-
wling hours per boat in each fishing season. 
Allowance was made for the increased effi-
ciency of the vessels, such as higher horse 
power, use of large synthetic nets and 
length of towing hours at sea. Saetersdal 
et a!. (1965) observed 3% annual increase 
in fishing efficiency of boats that employ 
000 
300 
200 ~ 
' 
' 
100 j 
" 
Fig. 3. Correlation between fishing effort and catch 
per hour 
1979 
DEMERSAL FISHERJES OFF ORISSA COAST 103 
Table 1. Annual trmvl landings of demersal fishes at Paradeep 
Total catch of Total annual landings 
prawn and fish by tonnes 
government boats 
Year Government Total boats in Prawn & 
boats the region tonnes fish Prawn 
1692-'63 4 4 192.99 192.99 11.54 
1963-'64 6 6 317.26 317.26 19.42 
1964-'65 10 10 262.75 262.75 23.65 
1965-'66 15 18 794.54 794.54 45.13 
1966-'67 19 22 614.74 614.74 43.03 
1967-'68 11 14 250.21 250.21 27.52 
1968-'69 12 22 565.79 1541.49 83.67 
1969-'70 13 23 1399.60 2954.65 278.11 
1070-'71 10 20 911.87 1912.73 192.85 
1971-'72 21 29 1708.39 3249.86 454.55 
1972-'73 23 31 2468.74 4599.56 313.74 
1973-'74 24 36 1110.59 2292.03 142.90 
1974-'75 24 41 518.35 1089.92 235.42 
1975-'76 25 208 3088.92 26681.14 3232.75 
1976-'77 21 344 2232.22 16029.88 1336.97 
1977-'78 5 242 200.67 14102.80 2368.24 
Table 2. Total fishing effort and estimated fishing effort of all the boats at Paradeep 
Year Depth Fishing Trawling Trawling 
fathoms effort of hours hours 
govern- with without 
ment catch catch 
boats in '000 h % 
trawling 
hours 
1962-'63 6-10 1528 1.764 4.69 
1963-'64 6-10 2245 2.754 4.94 
1964-'65 6-10 3886 4.500 7.63 
1965-'66 6-10 7080 10.545 7.99 
1966-'67 6-10 7676 11.350 9.37 
1967-'68 6-10 3080 5.605 9.81 
1968-'69 11-15 5064 15.930 11.45 
1969-'70 11-15 6308 15.816 11.96 
1970-'71 11-15 4864 12.948 13.00 
1971-'72 11-15 20332 37.854 18.35 
1972-'73 ll-15 28032 48.930 21.56 
1973-'74 11-15 10324 23.178 22.59 
1974-'75 11-15 8824 19.302 25.03 
1975-'76 20--25 37396 387.109 26.93 
1976-'77 20-25 81476 674.739 28.01 
1977-'78 20--25 4572 411.590 29.84 
larger purse seines. Using data on horse 
power of boats, size, design and constru-
ction of nets, estimates of increase in 
efficiency as in Table 4 were obtained. A 
revision has been made of the estimate on 
the effect of increase in towing hours with 
no catch on the efficiency (Table 5). 
The relative increase in effort was found 
Vol. 16 
First Total traw- Effi- Corrected 
estimate ling hoursx ciency estimate 
'000 h Average factor (2nd esti-
trawling mate) 
hours 'OOOh 
'OOOh 
1.847 1.568 0 1.568 
2.890 2.448 0.257 2.511 
4.843 4.000 0.443 4.177 
11.387 9.490 1.474 10.889 
12.413 10.215 1.666 11.917 
6.155 5.605 1.177 6.265 
17.754 11.947 1.884 14.198 
17.708 11.862 1.927 14.148 
14.631 10.790 2.326 13.300 
44.800 31.545 1.838 37.343 
59.479 40.775 1.829 48.232 
28.414 21.246 2.003 25.501 
24.133 19.302 2.183 23.515 
491.357 265.446 3.511 358.644 
863.733 501.234 3.556 679.472 
534.408 288.113 3.406 386.244 
significant (Table 2). The total annual 
landings of demersal fish as a whole and 
prawn caught in bottom trawl (Table 1) 
divided by various estimates of fishing 
effort (Table 2) provided the estimates of 
catch per unit effort (Table 3). All the 
estimates of catch per unit effort declined 
in three stages, that is, from 1962-'63 to 
Table?. Monthly average catch per hour 
October November December January February March 
Para- Asta- Damo- Para- Asta- Damo- Para- Asta- Damo- Para- Asta- Damo- Para- Asta- Damo- Para- Asta- Damo-
deep rang darpur deep rang darpur deep rang darpur deep rang darpur deep rang darpur deep rang darpur 
Prawns 0.47 1.6 1.37 1.11 23.79 2.33 1.40 13.14 0.73 0.46 2.38 0.51 1.07 11.80 0.24 1.06 8.55 0.06 
Pomfret 0.21 1.5 - 0.56 3.24 - 0.84 5.26 1.24 0.29 5.11 0.59 0.79 4.62 4.26 0.80 4.64 0.03 
Clupeiform fishes 0.51 0.2 1.02 1.36 1.29 1.11 3.48 0.67 3.78 4.67 1.09 2.13 4.84 0.51 2.17 5.09 0.73 0.98 
Polynemids - - - - 0.02 - 0.59 0.03 - 0.66 0.08 0.59 0.02 - 0.78 0.03 
Sciaenids 2.98 2.1 2.29 5.94 23.14 2.68 10.61 26.97 4.35 12.42 44.56 3.07 13.04 7.59 3.39 14.15 7.73 1.26 
Ribbon fishes 0.28 - 0.35 0.47 2.66 0.37 1.89 3.23 0.41 2.44 2.86 0.39 2.49 0.94 0.43 1.81 1.56 0.29 
Silver bellies & glass fishes 0.10 - 0.12 0.45 - 0.17 2.97 - 0.34 1.26 - 0.29 1.77 - 1.21 1.25 
Catfishes 0.14 0.6 0.41 0.21 5.02 0.76 0.44 2.43 0.91 0.47 6.82 0.67 0.46 1.64 0.71 0.30 2.37 0.37 
Eel - 1.0 - - 5.27 - - 3.76 - - 6.44 - 2.58 - 1.30 
Carangids - - - - 0.25 - - 0.92 - 2.14 - - 0.96 - 1.22 
Soles - 0.8 - - 2.14 - - 0.62 - - 0.93 - - 0.50 - - 0.51 
Elasmo branchs - 0.5 - - 1.36 - - 0.77 - - 1.26 - - 0.55 - - 0.87 
Miscellaneous 2.20 2.0 3.1 7.15 4.39 5.63 10.92 1.80 13.44 12.40 2.79 5.01 14.35 1.39 5.63 15.71 2.06 3.16 
Total 6.89 10.3 8.54 16.92 73.05 12.88 30.34 62.59 24.86 34.15 77.71 12.37 37.92 34.88 16.83 40.91 32.84 6.10 
....... 
0 
0'\ 
0 
:-o 
l:ti 
H 
IZl 
::€J 
>--IZl 
DEMERSAL FISHERIES OFF ORISSA COAST 107 
At Astarang, during the same period, 
prawns, clupeiform fishes, soles, elasmo-
branchs and miscellaneous groups showed 
a peak in November followed by pomfrets, 
ribbon fishes and silver bellies in December. 
In January, polynemids, sciaenids, cat 
fishes, eel and carangids dominated the catch 
(Table 7). The demersal fish stock was 
maximum from November to January. 
The results show that off Devi river mouth 
is more productive and under exploited. 
The fishes appear to migrate to inshore 
waters from north to south, first to off 
Mahanadi area in October and off Devi in 
November. 
The co-operation rendered by the officers of 
State Fisheries Department, Exploratory Fisheries 
Project (Government of India) and private boat 
owners at Paradeep is gratefully acknowledged. 
References 
Bane1ji, S.K. & Krishnan, T.S. (1973) 
Proc. Symp. Living Resources of the 
Seas Around India, Cochin, p. 158 
Vol. 16 
Biswas, K.P. (1978) Fish. Tee/mol. 15, 37 
Borisov, N. I. (1962) Experimental and 
Exploratory Fishing in the Bay of Bengal, 
FAO Report to the Government of India, 
1466 
Gulland, J. A. (1968) The Concept of 
Maximum Sustainable Yield and Fishery 
Management, FAO Fish Stock Evalua-
tion Branch Report 
Misra, P.M., Roy, A.B. & Sengupta, S.K. 
(1972) Pro c. Seminar on M ariculture 
and Mechanised Fishing, Madras, p. 180 
Poliakov, M.P. (1962) Exploratory Tra-
wling in Bay of Bengal, FAO Report to 
Government of India, 1573 
Roy, J.C. & Roy, S. (1972) Proc. Indo-
Pacif Fish. Coun. 15, 40 
Saetersdal, G., Tsukayama, I. & Alegre, B. 
(1965) Bol. Inst. Mar. Peru. 1, 85 


Inshore demersal fisheries off Orissa coast

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Inshore demersal fisheries off Orissa coast

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