hand and longlining in the vicinity

1 Pages 1-10

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Deep-water Bottom Hand and Longlining
in the vicinity of Wewak, E. Sepik
'
Province. A Preliminary Survey.
by
P. Sundberg & R. J. Campbell*
REPORT NO. 82-6.
* Wama Marine Products Pty., Ltd. ,
P. O. Box 308,
WEWAK.
EAST SEPIK PROVINCE.

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1
INTRODUCTION.
In January 1982, the Fisheries & Survey Branch commenced a deep-water
bottom fishing project. The main objectives of this project are to
�assess the potential for development of deep-water (80 - 300m) fish as
a harvestable resource, a�d.to gain basic biological information on the
fish communities living at these depths.
Surveys have so far been carried out in Milne Bay, around Port Moresby
and Manus Island (Research Report No. 82�3) . This report presents the
results of a deep-water bottom fishing survey carried out in the vicinity
of Wewak, East Sepik Province from the 26th July to 10th September, 1982
THE FISHING AREAS.
:J
/",Three main areas were fished as illustrated in Figure 1.
In section 1
the bottom slopes gently from 60m with oc c asional steeper slopes,
partic ularly on the northern side of underwater mountains. The bottom
type is mainly roc k, but some mud patc hes were found. Strong currents
were only oc c asionally enc ountered in this sec tion during the survey
period. Handlining trips numbers: 1,3 to 5 and 8 to 11 (Table 1), were
c arried out in this sec tion. In addition all longlining was undertaken
in Sec tion 1.
Section 2 is characterized by steep slopes between 60 and 250m and by
strong cu�rents'(>3 knots) which made fishing either difficult or
impossible during the survey period. Fishing in this section cannot be
recommended if these currents are persistent. They may however change
during the wet season when the direction of the prevailing winds are
north--westerly. Fishing trips 6 and 7 were undertaken in this section
(Table 1) .

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2
I
..
0
5 n.mil•
Fig.1.
The sections surveyed (1-3), to�eat:1er with the locations
of sites A and B. Shading inc.icates places where strong
currents persisted during the survey period.

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'l'ADLI!: I. Jletuilu oft.he Hot.tom Handliuini:i; cH.rried out
in the Weva.k Area.
-1!.!£. Ti.me of
lW..
llours
~
Position
L!.W .l.:!.l.:L
�
!!2.:_2!
J1.lL.l!
l
;-·u.
b
3
4
5
6
7
B
9
10
Ha
b
c
d
e
l'
g
12a
b
c
d
night
<luy
day
2.0
0.7
o.B
day
3.6
night/
morning
5.2
night
2.0
night
4.5
duy
•
afternoon/
night
10.3
afternoon/
•
night
morning
2.3
afternoon
afternoon
afternoon
night
night
night
morning
o.8
1.5
3.3
1.2
'1.9
1.3
1.8
night
2.8
night/
morning
11,Q
afternoon 2.3
night
6.3
5.5
4.5
7.5
16
10.5
22.5
•
13.5
•
6.3
25.0
41.5
1"10
03 33.2' 1113 43.3�
5
240
03 2·1.21 143 30.51
1
160
·03 31.81 143 38.3'
1
160
03 31.61 143 43.31
2
110
03 30.11 143 40.7•
26
100.
03 31.81 143 44.9•
3
210
03 21.3• 143 38,01
6
150•• 03 2li .81••1113 40.01••
170
03 30,21 143 40.7'
22
••
170
03 30.21••11i3 41.81••
125
03 31.9' 1113 44.31
15
100
03 32.81 1113 43.11
0
230
03 31.01 143 li5.01
2
150
03 30.6' 143 44.8'
7
Bo
03 31.5' 143 42.4'
0
120
03 30.61 143 41.9'
Q
95
03 31,5• 1'13 40.61
1
120
03 30.3' 143 40.6'
1
220
03 19.71 143 27.5•
2
160
03 20.01 143 27.7'
3
115
03 22.61 141 40.11
6
Bo
03 20.81 143 26.7•
23
83.3
o.'I
4.o
36.0
77 .3
6.1
112.6
2·1.·1
1.1
4.8
5.0
7.5
1.5
4.7
98.3
3.3
34.1
0
9.0
25.0
0
0
1.0
3.5
7.0
10.7
14.4
80.9
7.4
0
3.0
3.8
0
0
o.4
1.0
1.2
1.4
3.1
6.5
TOTALS
MEANS
(per trip)
58.5
152.8
4.9
12.7
126
533.6
10.5
44.5
4 .2
J
'l'vpe of:
.lli
Ml'
rock
Ml'
mud
MT
mud
MT
rock
MT
rock
DT
rock
MT
rock
MT
rock
MT
1
MT
rock
MT
mud
MT
rock
�T
rock
MT
rock
MT
rock
MT
rock
MT
rock
MT
rock
MT
rock
MT
rock
*
**
Bait:
Aborted because of strong currents.
Approx. depth and position.
MT - Mackerel tuna.
DT - Dogtooth tuna.

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4
Section 3 is similar to 2 in bottom topography, but strong currents
were only encountered in one area (marked by shading in Figure 1) .
Trip 12 was carried out in this section.
Two spots outside these three main sections were tried, A and B in
Figure 1 (Trip 2) . Both are situated on a gently sloping mud bottom
In our experience rock bottom is more productive than mud and these
two spots are not recommended for further fishing.
BOAT AND EQUIPMENT
},Fishing was carried out from M.V, 'Tangir'.
A plywood, 8.6m catamaran
of Alia design, powered by a 25hp outboard motor. The handling gear
consisted of two wooden hand reels each carrying 400m of 80-150kg test
monofilament line. The design of the handreels and the terminal rig
are illustrated in. Figures 2 and 3. A boat of this size could be fitted
with four hand reels. A Furono 600 echosounder was used for finding
suitable fishing spots.
j-The longlining gear used during this survey consisted of 10 PVC pipes
attached to a submerged horizontal float line carried between two
vertical main lines which had weights 9n the bottom and floats on the
� top (Figure 4a). Each PVC pipe carried 14 hooks attached to the PVC
pipe by a swivel to reduce tangling (Figure 4b) . The pipes were
suspended from a float and weighted, at the bottom, by a lkg lead weight.
This arrangement caused the PVC pipe to stand vertically near the
bottom. To avoid entanglement during transportation, each dropline
(consisting of a PVC pipe, baited hooks, a float and a weight) was stored
inside another, larger diameter, PVC" pipe. Details of the method are
given in Australian Fisheries, volume 41, number 2, February 1982.

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A---------=~ -==) - - - \\
I
w
"-
>-
...
z
<
0
:>:
<
Vl
z
"'
w-w'
w "'
V.l..
0
z
w <(
� ::c
w
"'
"
<!)

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6
Longline
1- 30cm----t
Mustad tuna circle
hook No.39960ST.
(size 3,4,5,6, or 7).
1 or 2kg lead weight.
Fig.3. Terminal rig for deep bottom fishing.

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7
A
main
lin•
float line
B
drepl ine
unit
Fig.4.
Bottom longlining gear.
A. Showing the main, float and drop lines.
B. Showing a 14 hook, PVC pipe dropline.

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8
FISHING PROCEDURE,
All handling was carried out from an anchored position. Depending on
wind and current direction, anchoring was done on the shallow or deep
part of the slope, so that by paying out anchor rope, a suitable fishing
dept.h was reached. The terminal rig was allowed to reach the bottom,
and an extra one or two meters of fishing line was then paid out to
make sure that the hooks were always close to the bottom.
The longlines were set whilst the boat drifted and the ready baited
droplines were removed from their containers one at a time, and snapped
on to the mainline loops as they passed over the stern. It took about
10 minutes to set a 140-hook set, and between 15 and 20 minutes to haul
it. Although much more rapid than the conventional longline, the system
has some drawbacks, the main one being that the droplines became
entangled in the mainline when hauled from great depths.
Locally caught tuna, mainly mackerel tuna, was used for bait and when
possible these were caught by trolling whilst steaming to and from the
fishing grounds. Unfortunately the M.V. 'Tangir' was too slow to keep
up with the majority of the schools of mackerel tuna, which are
abundant in the area, and tuna was only occasionally caught.
The deep-water fish were identified to species, or t·o the nearest higher
group, w�ichever was possible, and weighed. The gutted fish were stored
on ice and sold fresh on arrival in Wewak.
RESULTS AND DISCUSSION.
A total of 58. 5 hours of bottom handling and 3. 5 soak hours of longlining
was completed during the survey. Details of the trips are given in Tables
I and II. The combined total catch was 121 bony fish, representing 17
species (Table III); with a total weight of 362 kg.

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TABLE II.
Details of the Longlining carried out during the Survey
in the Wewak Area.
Set No.
Soak time
No. of hooks ( mins )
Depth
(m)
1
140
2
i4o
3
100
4
100
5
80
20
210
25
180
50
190
50
160
55
190
TOTALS
200
MEANS ( per set)
40
Position
Lat.
Long.
�To. fish
Weight (kg)
03 31.01 143 43,3'
6
03 31. 01 143 42.9•
0
03 30.9' 143 42. 71
0
03 30. 2' 143 42.21
1
03 30. 21 143 41. 8'
0
11. 1
0
0
3. 2
0
7
14.3
1.4
2.9
Soak time is the time between when the first dropline was set and the last was hauled.
\\0

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TABLE III.
List of the species, number of fish for each species,
weight (in kg), percentage of total weight, mean weight
and depth distribution for the species encountered in the
survey around Wewak,
No. of
fish
Total
weight
(kg)
% of
total
weight
Mean
weight
( kg )
Depth
distribution
(m)
PA.l6ti.pomoide;.1 mu£tiderv.,
Large-Scaled Jobfish
71
Ca.Jta.nX -6pp
Trevally
13
La.mni�M�
Sharks
12
E£e£.l6 eMbuneu£M
Short-tailed Red Snapper 11
Lutja.nM ma.£a.b�ieM
Scarlet Sea-Perch
6
Epinepha.£u<1 eompAU<lu-6
Black-Banded Rock-Cod
4
E. ma.gnieuti.-6t
3
Ma.eo£M nig�
Black-and-White Rock-Cod
2
Epinepha.£M moAAhua.
Brown-Striped Grouper
2
E:te£.l6 oeu£a.:tM
Long-Tailed Red Snapper
1
PA.l6ti.pomoide;.1 �i!a.mentn<1.l6-
Rosy Jobfish
1
S�io£a. dumeAi!ii
Deep-Water Amberjack
1
Lu:tja.nM <Ip,
1
E£ega.:t.l6 bipinnu£a.�
Rainbow Runner
·1
Lu:tja.nM bohM
Red Sea-Bass
1
Le:thAinM minia.�
Long-Nosed Emperor
·1
Ca.££0<1phyAa.ena. :toxeuma.
Foster's Sea-Pike.
1
Lefuinida.e
1
196. 1
33. 8
181. 6
33. 6
11. 2
25. 0
12. 8
6. 8
4. o
3. 2
7. 0
6.o
2. 5
3. 6
4. o
4. 4
4.5
3. 2
35. 8
6. 2
33. 2
6. 1
2. 0
4. 6
2. 3
1. 2
0. 7
0.6
1. 3
1. 1
0. 5
0. 7
0.7
0. 8
0. 8
o. 6
2. 8
2. 6
15. 1
3. 1
1. 9
6. 3
4. 3
3. 4
2. 0
3. 2
7.0
6. o
2. 5
3. 6
4. o
4. 4
4. 5
3. 2
80-210
80-170
95-240
210-240
80-140
80-170
160-210
80
80-170
210
170
230
125
80
80
80
80
115
I-'
0

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11
� In addition 12 sharks ere caught and these weighed '18lkg, The average
weight pe• fish was 2.9kg which is very similar to the 2. 6 average
weight reported by Fusimalohi & Crossland (1980) from an earlier survey
in Papua New Guinea. It is however lower than the average fish weight
3. 6kg reported by Sundberg & Richards (Research Report No. 82-3).
However, Sundberg & Richards fished generally in deeper water, and in
their report noted that mean weight tends to increase with depth,
The species composition varied between the three sections and the greatest
diversity was found in Section 3 (Figure 1) . The catch in Section 1
(Figure 1) mainly consisted of P�i-0tipomoidcv., muitidel'I/.>, whilst the
�"" dominant species in Section 2 was E:teii-0 cattbuncuiU-O • However the number
of hours spent fishing is insufficient to draw conclusions concerning
species diversity.
The mean catch rate, including sharks, for the survey was 4,2kg ungutted
weight/reel x hours. This figure is similar to those obtained in earlier
surveys in Papua New Guinea; Fusimalohi & Crossland, (1980) : 4.9kg,
Sundberg & Richards, ( op. cit): 3. 7kg (excluding sharks) . The mean catch
rate in this survey was slightly lower than those obtained in other areas
of the South Pacific, 5. 6kg, Table IV.
A feature of the fishing, especially in Section 1, was the large number
of sharks• caught. They caused problems by attacking hooked fish and by
damaging the gear, but there is a good market for sharks in Wewa.k and it
may be profitable to actively fish for them. We found1t- he most effective
method of catching sharks was to attach a baited hook on a two meter long
leader wire (or better still a chain) to a float with a diameter of around
30cm. The float was connected to the boat by a 20m long rope. The sharks,
hav1ng followed the fish which were caught on the handline upto the

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12
TABLE IV.
Average catch per unit effort in countries where the
South Pacific Commission Deep Sea Development Project
has operated (from Mead, 1980).
American Samoa
Trust Territory of the
Pacific Islands
New Caledonia
Niue
Vanuatu
Tonga
Fiji
MEAN VALUE:
Kg/reel x hours
4. 4
9.6, 3,3, 4.1, 6. 9
7. 6
2. 8, 7,0
3. 1
3.6, 5.7
9, 3
5,6

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J:3
surface, circled around the boat for a while and were easily caught on
the baited hook hanging from the buoy. Sharks caught in this way are
not included in the catch rates reported in this paper.
Only about 30% of the trip hours were actually spent fishing. This was
due to several reasons, the main ones being: the long distances to the
fishing grounds, a slow boat, bad weather, and also because the crew
were unfamiliar with both the fishing technique and the area. One way
of increasing the catch per trip would be to increase the proportion of
time spent fishing. This can be done by using faster boats, spending
more time at the fishing ground per fishing trip and by basing the fishing
vessels closer to suitable reefs. This proportion will also increase with
increasing experience and knowledge of both fishing techniques and fishing
areas.
RECOMMENDATIONS.
There seems to be a commercial number of bottom fish in the surveyed areas,
but before any final conclusions are made on the viability of a year round
commercial or artisanal fishery, we recommend that:
1. Bottom fishing trials, preferably from a commercially operated
vessel, should continue over at least one full year, and the
I
results be carefully monitored.
2. More trials should be carried out with the type of bottom
longlining used inthe survey.
3. Other areas, for example the Tarawai and Wallis Islands, should
be surveyed together with the ones discussed in this report.
4. Methods of increasing the ratio of fishing time to total trip
time should be investigated.
5. Marketing and handling of sharks should be fully investigated.

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lli
An economic analysis is presented in Table V. This shows that it is
possible, with the catch rate obtained during the survey, to support
a crew of three using a plywood catamaran of the Alia design provided
that the same catch rate can be achieved throughout the year.
ACKNOWLEDGEMENTS.
It would not have been possible to carry out this survey without the
help and support of Otto Abu, Andrew Gobikambe, Mongop Waramapi, Andrew
Panjap, Konni Bakan and Bo Alexander and we thank them all for the
interest they have shown.
REFERENCES.
Fusimalohi T & J. Crossland. 1980. Report on the South Pacific
Commission Deep Sea Fisheries Development Program in West New
Britain, Papua New Guinea. S.P.C. Noumea, March 1980. 14 p.
Mead, P. 1980. Report on the Visit of the South Pacific Commission
Deep Sea Fisheries Development Project to Fiji. S.P.C. Noumea,
December 1980. 21 p.

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15
TABLE V. Cost benefit analysis of 8. 6m Alia-type catamaran bottom
fishing from an island in the East Sepik Province.
ASSUMPTIONS.
1. Vessel operating in deep water close to a village.
2. Five vessels serviced three times a week by a 8. 6m inboard diesel
powered collection vessel.
3. Fishing vessels powered by 15hp outboard motors. Total
construction cost (including motor) of K4300,.-/fishing vessel.
4. Vessel depreciated over five years.
5, Vessel operated by three crew using three reels.
EARNINGS/YEAR.
3 trip/week, 40 weeks/year, 120 trips/year
10 hours bottom fishing/trip
Total hours/boat using three reels
Catch rate of 4. 2kg/reel and hour
Total catch/year ungutted fish
Total gutted fish (80% recovery)
Sold at 80t/kg.
3600 hours
15120kg
12096kg
K9676.
EXPENSES/YEAR.
Replacement cost of vessel and motor over
5 years.
Fuel costs/year (120 trips at K5/trip)
Vessel maintenance and repair
Fishing gear replacement
Bait KB/trip
Ice costs (10,000kg at 6t/kg)
K860
K600
K360
K300
K960
K600
Total expenses
Returns to crew/year
K3680
K5996
NOTE.
For a family crew this return gives approximately K76 per man per
fortnight which is a reasonable rural wage. A vessel operated on a
family basis may also exceed 120 trips per year by rotating crews,
thereby increasing the gross family income.