Fishing gear and methods

This volume is a result of the surveys on marine fishing gear and methods in Vietnam from January 1997 to December 1999. The survey locations are selected from provinces where fisheries developed and are shown in Figure 1 . The abbreviations and symbols used in illustrations and the surveys are in accordance with the use as in the first, second and third volumes ( Thailand , Malaysia and Philippines ). The number of surveyed fishing gear types is shown in Table 6 . The data, which are introduced in this monograph, were based on the data contained in reports of Vietnamese Ministry of Fisheries and the data from practical surveys conducted by the Research Institute of Marine Products.

1) Drawing of the horizontal length of surrounding nets, seine net and gill net depends on the length of the float line, and the vertical depth depends on the vertical hanging ratio of netting. In the case of gill nets with side lines, the depth of the side line is drawn same scale to float line. The width of netting panels, or sections of trawl are drawn as a half of the stretched netting width, and the depth or length according to the vertical hanging ratio of netting. Some

Table 6. Amount of fishing gear designs and technical papers collected from the surveys in Vietnam .types of fishing gear are shown by schemata or overall sketches with the dimensions indicated applicably.

Group of Fishing gear	Amount of designs
Beam trawl	8
Bottom otter trawl	8
Bottom oter trawl with booms	8
Bottom pair trawl	19
Purse seine	22
Beach seine	2
Drif gill net	22
Bottom gill net	22
Trammel net	9
Hook and line	21
Lift net	12
Traps	14
Cast net	3
Scoop net	6
Dredge	1
Total	177

2) General outline drawings, such as of the rig of a complete gear, and detailed drawings of components, are not to scale, but the main dimensions are given.

3) Dimensions are given only in meters (m) and millimeters (mm). The units are not indicated but can be easily be recognized, as follows:

Meter : Length of footropes, headlines, floatlines, etc. used with decimals of hundredths (e.g., 5.25, 90.20).

Millimeter : Mesh size (stretched), diameter of ropes, floats, etc. used without decimal or with decimals of tenths (e.g., 15; 325 or 2.5 ; 15.8)

4) Mass and weight are indicated in the units of kilogram (kg) and gram (g). Buoyancies of floats and sink load of net yams or ropes are shown by kilogram-force (kgf) or gram-force (gf).

7) The mesh size given in millimeters (mm) is understood to be the distance between the centers of two opposite knots in the same mesh when fully stretched.

8) The number of meshes in a straight row along the edge shows the width and length or depth of net panels or sections.

9) The shape of netting section is indicated by the cutting rate at its edge. A tabulation of common cutting rates for a practical rang of taper ratios is shown in Appendix 2 .

10) The term hanging ratio (E) designates the ratio between the length of a given portion of the mounting rope and the length of the stretched netting hung on this portion of the rope.

11) When there are two or more variants in the construction of gear or manner of use, there are indicated in the title and opposite thedrawing by Roman numerals (I, II,...). Where these variants refer to only one component part of gear, other possible ways of making this part are shown with the abbreviation ALT.

12) Sequence in fishing operation is shown by sketches with circled Arabic numerals (1, 2,...) which indicate the sequence of operational stages.

13) Parts of gear drawn in detail are indicated by circled capital letters (A B...).

Loa	Length of over all fishing boat
GT	Gross tonnage
Hp	Horse power
EG	Electric generator
LL	Luning lamp
BAM	Bamboo
BR	Brass
CEM	Cement
CLAY	Baked clay
COMB	Combination rope
Fe	Iron
Fp	Foam plastic
MAT	Material
MONO	Monofilament
PA	Polyamid
Pb	Lead
PE	Polyethylene
PL	Plastic
PP	Polypropylen
RUB	Rubber
S	S Twist
SST	Stainless steel
SW	Swivel
WD	Wood
WIRE	Steel wire rope
Z	Z Twist
o/	Diameter
	Upper panel
	Lower panel
ll	Side panel
	Purse ring
ll	Thichness
	Approximately
	Circumference
xxxxx	Braided
zzzzzz	Twisted
	Current
	Wind

	1	2	3	4	5	6	7	8	9	10
1	AB	1T2B	1T1B	3T2B	2T1B	5T2B	3T1B	7T2B	4T1B	9T2B
2	1N2B	AB	1T4B	1T2B	3T4B	1T1B	5T4B	3T2B	7T4B	2T1B
3	1N1B	1N4B	AB	1T6B	1T3B	1T2B	2T3B	5T6B	1T1B	7T6B
4	3N2B	1N2B	1N6B	AB	1T8B	1T4B	3T8B	1T2B	5T8B	3T4B
5	2N1B	3N4B	1N3B	1N8B	AB	1T10B	1T5B	3T10B	2T5B	1T2B
6	5N2B	1N1B	1N2B	1N4B	1N10B	AB	1T14B	1T7B	1T4B	1T3B
7	3N1B	5N4B	2N3B	3N8B	1N5B	1N12B	AB	1T14B	1T7B	3T14B
8	1N2B	3N2B	5N6B	1N2B	3N10B	1N6B	1N14B	AB	1T16B	1T8B
9	4N1B	7N4B	1N1B	5N8B	2N5B	1N4B	1N7B	1N16B	AB	1T18B
10	9N2B	2N1B	7N6B	3N4B	1N2B	1N3B	3N14B	1N8B	1N18B	AB
11	5N1B	9N4B	4N3B	7N8B	3N5B	5N12B	2N7B	3N16B	1N9B	1N20B
12	11N2B	5N2B	3N2B	1N1B	7N10B	1N2B	5N14B	1N4B	1N6B	1N10B
13	6N1B	11N4B	5N3B	9N8B	4N5B	7N12B	3N7B	5N16B	2N9B	3N20B
14	13N2B	3N1B	11N6B	5N3B	9N10B	2N3B	1N2B	3N8B	5N18B	1N5B
15	7N1B	13N4B	2N1B	11N8B	1N1B	3N4B	4N7B	7N16B	1N3B	1N4B
16	15N2B	7N2B	13N6B	3N2B	11N10B	5N6B	9N14B	1N2B	7N18B	3N10B
17	8N1B	15N4B	7N3B	13N8B	6N5B	11N12B	5N7B	9N16B	4N9B	7N20B
18	17N2B	4N1B	5N2B	7N4B	13N10B	1N1B	11N14B	5N8B	1N2B	2N5B
19	9N1B	17N4B	8N3B	15N8B	7N5B	13N12B	6N7B	11N16B	5N9B	9N20B