Fishing experiments were conducted simultaneously with frame nets and trammel nets in the Hirakud Reservoir and the results indicated the relative superiority of frame nets, whose catch rate was two times more than that of the trammel nets

Khan, A.A.

Naidu, R.M.

Narayanappa, G.

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co RATIVE EFFICIE CY OF FRAME 
ND TRAM El NETS 
ETS 
R. M. NAIDU, A. A, KHAN & G. NARAYANAPPA 
C. I. F. L Sub-station, Bur/a, Orissa 
Fishing experiments were conducted simultaneously with 
frame nets and trammel nets in the Hjrakud Reservoir and 
tbe results indicated the relatjve superiority of frame nets, 
whose catch rate was two times more than that of the trammel nets. 
Jf NTRODUCTION 
The entangle nets are known for 
their fish catching efficiency in a water 
body where the fishery is of a diffused 
nature. Sulochanan et al. (1968) con-
ducted comparative studies with simple, 
vertical line and frame nets and recorded 
that frame nets were 1.4 to 4.76 times 
more effective than simple gill nets. 
Naidu and George (1972) subsequently 
experimented for the effectiveness of 
frame size and recommended that frame 
nets with 1. 75 m. compartments were 
more effective for the endemic population 
of the Hirakud reservoir. The other 
entangling gear 1ike trammel nets proved 
to be 2.5 to 5 times more efficient than 
the 'Rangoon' nets, when they were 
operated in the Mettur-Dam reservoir 
(Gulbadam::w, 1962). Since the frame and 
trammel nets come under the same 
category of entangling gear, comparative 
fishing experiments were carried out with 
both the type;; in order to evaluate the 
relative efficiency of each gear. 
VoL 13 No. 1 1976 
MATERIALS AND METHODS 
Ten units each of frame and trammel 
nets having 35 im. length and 5.25 m. 
hung depth were operated. The 
compartments in the frame nets were 
1. 75 m. and the ratio of inner and outer 
mesh in trammel nets was 1:3. The 
design details of nets have a-lready been 
given by Kuriyan (1973). During oper-
ations the nets were set both parallel 
and perpendicular to the shore. The net 
positions were interchanged every day so 
as to give equal chance to b.)th the 
units. The weight and number of each 
species of fish caught by both units were 
recorded separately. 
RESULTS AND DISCUSSION 
The catch per l 000 sq. m. of webbing 
of frame and trammel nets for each 
year and for the [Otal period are given 
m Table I. 
From the Table it IS evident that 
frame nets are more efficient and on an 
59 
Naidu, 1(f1an & Nnrnyanapp(ll cfficienq; o{ f-rame and trammel nets 
TABLE I 
Catch details of frame and trammel nets for the years 1972-74 
Year Total area in sq. m. Total catch in kg. 
Catch/100 sq. m. 
of webbing in kg. 
frame trammel frame trammel frame trammel 
~------------------------------- --------------------------------------------------------
1972 197125 191380 888.90 440.80 4.50 2.30 
1973 153565 149750 856.30 244.30 5.57 1.63 
1974 143375 131400 387.05 252.60 2.69 1.92 
For the total 
period 494065 472530 2132.25 937.70 4.31 1.98 
TABLE II 
Analysis of variance of fish catch 
Source S. S 
Total 50736.2394 
Between nets 416.1637 
Between species 1120.9772 
Between days 8539.3364 
Net X species 262.7144 
Net X days 32283.5293 
Species X days 25681.3983 
Residual 11431.1201 
t Significant at 5% level. 
* Significant at 1% level. 
average the catch of frame nets was 
two times than that of the trammel 
nets. 
The data were subjected to statistical 
analysis to assess the efficiency of the 
particular gear and also to ascertain 
whether a particular species has any 
preference in respect of any of the gear 
experimented. The analysed data are 
presented in Table II. 
Though the place, time and duration 
of operation of the nets were identical, 
60 
D. F. MS 
3229 
1 416.1637 * 
4 280.2443 "' 
322 26.5196 * 
4 65.6786 * 
322 18.1972 t 
1288 19.9389 * 
1288 8.8758 
frame nets gave better catches than 
trammel nets, the difference between 
the nets being significant at 1% level. 
When the proportion · of catch 'of 
one species to the total catch is different 
for the two nets, the interaction between 
net and species can be significant. Here 
it is significant at 1% level. The seasonal 
variation in availability of fish and 
difference in the pattern of seasonal 
variation of individual species account 
for the significance of the difference 
between days and the interaction between 
Fish. Techno!. 
Naidu, 'Kiian & Narayanappa: efficiency of frame and trammel nets 
TABLE III 
Catch details of frame and trammel nets during summer and winter 
Area of nets 
Season opera ted in sq. m. 
frame trammel 
Summer 150850 138770 
Winter 207940 201400 
species and days. The difference between 
the species is significant as the avail-
ability of different species differs. Catla 
catla and Silondia silondia were the 
dominant species am Jng the catch. The 
catch of Cirrihina . mrigala and Labeo 
fimbriatus were insignificant. Th~ 'other 
varieties' comprised mostly of unec_ono-
mical species. The frame net registered 
a higher catch rate and the catch can-
sisted of commercially important species. 
It is a known phenomena that during 
summer and winter seasons, the turbidity 
is less and hence the visibility is more. 
In order to ascertain the seasonal vari-
ation, if any, in the catch of the 
different types of . nets, the data were 
-analysed as shown in Table III. 
:rhe result of this analysis is also 
in conformity with that of the result 
given in Table I. The lower landings 
from the trammel nets can be attributed 
to the visibility factor. The trammel 
net with its three-welled structure make 
it more conspicuous in this case. 
VoL 13 No. 1 1976 
Catch in kg. Catch/1000 sq. m. 
of net in kg. 
frame trammel frame trammel 
448.20 180.55 2.97 1.30 
589.70 400.75 2.35 1.98 
ACKNOWLEDGEMENT 
The authors are highly indebted to 
Shri. G. K .. Kuriyan, Director, Central 
Institute of Fisheries Technology, Cochin 
for his encouragement in this study and 
to Shri. M. Velu, Officer-Tn-Charge, Craft 
& G.~ar Wing for critical evaluation of 
the manuscript. Thanks are due to 
Shri. A. K. Kesavan Nair, Assistant 
Statistician for the statistical analysis of 
the data. Initial help rendered by Shri. 
Y. _ Sreekrishna, former Assistant Fishery 
Scientist (Craft and Gear) is also grate-
fully acknowledged. 
REFERENCES 
Gulbadamov, S. B. 1962. FAO Report 
No. 1499. 
Kuriyan, G. K. 1973. Fish. Techno!; 10, 
1 : 1. 
Naidu, R, M. & V. C. George. 1972. 
Fish. Techno!; 9, 1 : 31. 
Sulochanan, P., V. C. George and R. M. 
Naidu. 1968. Fish. Techno!; S, 2 : 8 I. 
61 


Comparative efficiency of frame nets and trammel nets

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Comparative efficiency of frame nets and trammel nets

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