heui chun review fishing technology

(1)

Heui-Chun An, Sam-Kwang Cho, S

eong-Hun Kim

National Fisheries Research & Deve

lopment Institute, Korea

anhc1@Korea.kr

Review of

Fishing Technology to

Reduce Bycatch in Asia

29th Wakeﬁeld Fisheries Bycatch Symposium

(2)

!

Catch & Bycatch of Asia

!

Bycatch Reduction Technology

( Gillnet, Pot, Towed Gears)

!

Conclusion

(3)

22.9% / 6.0%

!

 

Catch = Marine capture production (Total 93,494 million ton)

!

 

Area Grand total 360.7 , Asia Sub Total 85.9 (million

), 23.8%

Catch and area proportions by fishing area, 2011

(4)

Global catch by fishing area, 2011

Data from FAO yearbook. Fishery and aquaculture statistics Yearbook (2011)

-

Asia Total: include Region No 57,61,71

-

Area Grand total 360.7 , Asia Sub Total 85.9 (million

), 23.8%

Region No.

Nominal regions

Catch (1,000MT)

(%)

61 Northwest Pacific

21,437

22.93 Global Total

93,494

100.00

(5)

Sea Food Culture of Asia

Fish meal

Fish sauce

Salted seafood

Dried fish products(pollack )

SeaFood

http://ourdailybrine.com/

http://100.empas.com/

Salted fermented seafood

http://www.pangasius-vietnam.com/

www.tradekorea.com

(6)

6

(Prof Arimoto, FAO/SEAFDEC Workshop on by‐catch and discards 2003 Bangkok)

Alaska Sea Grant - “bycatch” include retained incidental

catch, fishery discards, and unobserved mortalities as a

result of direct encounters with fishing gear

(7)

Up-dated Global Estimates of 6.8 mil. Tons (2005)

(8)

Sub Area

Ratio

By-Catch:Shrimp

References

II~VI

B i n t u n i ,

Kaimana,

D o l a k ,

Aru

4:1~21:1

Iskandar et al. (1993), Badrudin &

Karyana (1993), others (1993~2002)

By-catch ratio to shrimps caught by shrimp trawler in the

Arafura waters, Indonesia (1992~2001)

(9)

Growth overfishing and trash fish landings, Malaysia

AREA

Trash fish landings (tonnes)

_{% trash in}

trawl Landi

ngs

Trawlers

All methods

% by trawle

rs

West Coast Peninsular Malaysia

_132,304

_169,709

_77.96

_35.99

East Coast Peninsular Malaysia

_58,777

_60,599

_96.99

_38.54

Sabah, Sarawak & Labuan

_23,899

_31,362

_76.20

_16.88

Whole Malaysia

214,980

261,670

82.16

32.49

(10)

MATSUOKA T., 2009,Negative impacts in capture fisheries: bycatch and discards and derelict fishing gear and ghost fishing. PICES meeting.

GF :Ghost fishing.

Kaeser et.al.

Erzini et.al.

Nakashima-Matsuoka

Net length (m)

Net height (m)

.

Mesh size (mm)

～

Major GF species

Cat-sharks

Nursehound

Scorpionfishes

Sea breams

Threadsail filefish

Dragonet

GF duration (days)

GF mortality

(number)

(11)

Bycatch Reduction Methods

• BRD : Bycatch Reduction Devices

• TED, Fish eye, BED, JTED, ETC..,

Fishing Gear

Selectivity

(Mesh , Bar etc. )

Vent

BRD

Gillnet

○ Pot

○

○ Dredge

○

(12)

Bycatch Reduction in Snow Crab Gillnet, Korea

Park et al. 2003

Snow crab 97.12%

Spinyhead sculpin 0.81%

Pacific cod 0.18%

Catch rate of major species in snow crab gillnet

Trap, 560MT 12%

Other 3MT 0%

Trawl 47MT 1%

(13)

Catch per net by mesh size

150

180

210

240

270

300

330 Mesh size (mm)

Catch

number

/

net

_{Male (>90 mm)}

Male (≤90 mm)

Maximum carapace length / Mesh size

Re

Mesh selectivity of male snow c

rab

- Used mesh size : 180 ~300 mm (5steps)

- Retention Probability 0.5

_→

RL/m=0.356

(RL: Maximum carapace length, m: mesh size)

(14)

Item

Before 2002

After 2002

Mesh size of gillnets

180 – 270 mm

240 mm

≤

Fishing season

11.01 ~ 05.31

12.01 ~ 05.31

Landing size

(carapace length)

90mm

Female

×

Park et al. 2003

(15)

Use of escape vents to improve size and species selectivity of

collapsible pot for

Portunus pelagicus

in Thailand

- Collapsible crab pot: box shaped with size of 36

×

54 ×

19 cm

Boutson et al. (2009) - Four different shapes of escape vent (a), located a

t the bottom sides of the lower slope panel (b) use d to observe the escape behavior of blue swimmi ng crabs from the pot

http://en.wikipedia.org

Boutson et al. [2005] immature blue swimming crab catch: 32–42%

- Square-shaped escape vents were located at five pairs of different positions: on the lower slope panel at the corner (

1) and center (2), on the side panel at upper (3) and lower ( 4) positions, and at the top panel corner (5) to observe esca pe behavior of crabs from the same pot for the vent positio n experiment

"

 

Escape rate :

Square(70%) > Circle(18%) > Rectangular(10%) > Ellips(2%)

(16)

A Size selectivity for blue swimming crab acco rding to escape vent length when vent height w as fixed at 35 mm, b master curve for crab size (CL) according to vent length (VL)

- Blue swimming crab size sampl ed with conventional pots (open columns) and vented pots (shad ed columns)

- Size selectivity of 35 x 45 mm esca pe vent for blue swimming crab fro m the field trials with L50% = 46.9 mm, a = -25.9403, b = 0.5528, and SR = 4.0 mm, in comparison with t he result from the laboratory observ ation

Boutson et al. (2009)

First maturity size of crab

:

46 mm CL

L50%(vent

35 ×

45 mm)

= 46.9 mm

(17)

Tottori 2009 report

-

 

Red queen crab trap with vent.

-

 

Mesh size 130mm, vent dia 95mm

Size selectivity of red queen crab traps in Japan

- Selectivity curve of vented traps, the commercial trap

(150 mm mesh size)

- Selectivity master curve of circular escape vent in

trap for male red queen crab.

Landing

�� (��):

90mm,

L50 escape vent dia: 93mm

- Specification for the vents trap used in experiment

Mesh size 150mm, escape vents: 90, 100, 110 mm

(18)

Selectivity of Venus Clam Dredge in Korea

- Beam of dredge: 1,200L

×

_{370H mm, net 4m}

- Bar space : 12, 16, 20, 24, 35 mm

- Mesh size of net: 22, 24, 30, 41, 47 mm

Shellfish Dredge

KIM & Jo (2001)

http://terms.naver.com/entry.nhn?d ocId=774312

645 370

420

300 1,200

(19)

(b) Selection shell length

- Selection curves for venus clam,

Gomphina melanaegis

.

KIM & Jo (2001)

Mesh size (cm)

Sh

• First maturity length 25mm

• Optimum mesh size for 25mm Venus clam: 40.5mm

• Regulation: mesh size

≥

_{40mm , bar space}

≥

_15mm,

0.05 1.05 2.05 3.05 4.05 5.05 6.05 Shell length (cm)

Re

te

nt

io

n

(20)

Crab separator for flatfish seine

• Developed to exclude snow crab while retaining flatfish

wing

Belly

slope

Selection

mesh

Chaffer

Belly

slope

Snow crab reduction : approx. 90 %

Flatfish retention : approx. 85%

(21)

Plan of codend

Schematic diagram of codend

- Plan of codend and schematic diagram of codend and grid separator used in the fishing experiment

.

Selectivity of grid separator with horizontal bars

for beam trawl fishery in Tokyo Bay

Schematic diagram of grid separator

bar space: 13

1 5

2 0, 24 mm

Ohata et al. (2008)

(22)

Landing size:

marbled flounder- 15cm total length, with 11~21 mm

white-spotted conger- 35cm total length, with 5~17 mm

Ohata et al. (2008)

- Selectivity of grid separator for marbled flounder Pleuronectes yo kohamae plotted against a function of (body width) / (bar space) an d that for white-spotted conger Conger myriaster plotted as a functi on of (head height) / (bar space),

□: bar space 13 mm X: bar space 15 mm ▲:bar space 20 mm, ○ : bar space 24 mm.

white.spotted conger

- Proportion retained of each bar space from the master cur ve. Three arrowed lines indicate the range of head height fr om 8 to 14 mm for white-spotted conger Conger myriasfer

(23)

Development of JET

(Jellyfish excluder for Towed fishing gear)

Takayanagi (2007)

Nemopilema nomurai

Bell diameter 25~106 cm

Producing area of Nemopilema nomurai

Kuroshio Current

(24)

Jellyfish (damaging to fishery)

Distribution ratio of fish and jellyfish in survey trawl (2004~2007

)

(25)

□

_{Development of the JSS}

Jellyfish separator system

Cod-end

Cover net

Guiding net

S eparator net

Outlet

Net

Cutting net

Outlet

Chain

(26)

Cod-end

Cover-net

Jellyfish Exclu

sion rate

Catch loss rate

Jellyfish (kg)

Fish (kg)

Jellyfish (kg)

Fish (kg)

442.0

330.9 3,184.3

157 87.8%

(74.0~92.7)

32.2%

Experiment Results

(27)

Method of designing and manufacturing JET

(Jellyfish excluder for Towed fishing gear) for various towed fishing gears

- Separation of Jellyfish from target species by JET.

- A part of towed fishing gear where JET is inserted.

(28)

Research on by-catch of shrimp trawl fishery in Arafuru Sea

(volume, reduction devices, and utilization of discarded by-catch)

SEAFDEC (2005)

Ari Purbayanto, Ph.D

Professor in Fishing Technology

Department of Fisheries Resource Utilization Faculty of Fisheries and Marine Sciences

BOGOR AGRICULTURAL UNIVERSITY

Purbayanto (2013)

(29)

• The by-catch

is still the main problem on shrimp

trawl fishery in Arafuru sea, Indonesia.

• A large volume

of the by-catch is

discarded

• Presidential decree No. 39/1980 to ban the operation of Trawl

Net in Indonesia waters

• BED - Equipped Trawl(shrimp trawl) is permitted to be operate

d only in Arafuru sea at geograpic position of 130º E to the east

• Bycatch Excluder Device (BED) or Turtle Excluder Devices (T

ED)

– must be attached on shrimp trawl

net during operation

(30)

Mahiswara (2004) reported that:

TED super shooter decreased bycatch/towing/hour by 5% (12 cm grid space) an

d by 60% (4 cm grid space).

TED performance (815 shots, 3 years period)

turtle reduction

99%

stingray reduction

96%

large shark reduction

80%

sponge reduction

80%

shrimp loss

2 – 38%

Source: Eayrs (2006)

(31)

(a) TED super shooter (US type)

(b) Square mesh window

(c) Fish eye

Kind of Bycatch Reduction Devices

Purbayanto et al. (2007)

Mesh opening

22.50mm

31.75mm

Bar distance

(32)

Comparison between BRDs in reduncing by-catch

The by-catch reduction and shrimp loss of the BRDs tested compared to the control net

Percent reduction by weight

US-TED

Square Mesh

_Window

Fish Eye

By-catch reduction

_-(4.66)*

_5.98

_13.36

Shrimp loss

32.29

22.13

21.25 *) The bycatch increase compared to the control net.

(33)

JTED bar 1.75 mm saved 33 % young fish

80 Immature and trash fish

60 67 %

40 33 %

20

0 Retained

Escaped

pen = 12 cm

Widodo & Mahiswara (2007)

Purbayanto, 2013. Research on by-catch of shrimp trawl fishery in Arafuru Sea.WGFTFB 2013 meeting.

(34)

Utilization of discarded by-catch

utilizing the discarded by-catch

Increasing efficency of fisheries resource utilization in order to sustain

bio-diversity, environment, and food security for people prosperity

Development of

environmentally

friendly fishing tech.

Target

species

Fishing

By-catch

Processing

technology to utilize

discarded by-catch

Food

Purbayanto, 2013. Research on by-catch of shrimp tra wl fishery in Arafuru Sea.WGFTFB 2013 meeting.