Effects of fishing gear on quality – The SEAQUID-EFF project

01/10/2013 Fishing gear and effective catch handling workshop 2013

Daphné DeloofKaren Bekaert, Johan Robbens

Institute for Agricultural and Fisheries ResearchAnimal Sciences Unit

www.ilvo.vlaanderen.beAgriculture and Fisheries Policy Area

Aim of the study

2

To compare the beam trawl, otter trawl and gillnets and entangling nets trawl in terms of quality of whiting and sole

Sequid technology: objective alternative for QIM?

Aim of the study

3

Convincing the ship owners and their national association to turn away from the beam trawl in order to switch to an alternative methods

Improving the image and sustainability of the Belgian fleet, dominated by beam trawlers

Materials and methods

4

2011 : data collection on commercial ships (spring;summer;autumn/winter)

Analysis on board of commercial ships: Initial muscle pH Onset of rigor mortis External damages – Injury Index Method (IIM) Mortality rate

Analysis in the lab by shelf life study: QIM TVB-N

pH and rigor mortis in sole

5

pH Rigor mortis

Visser ijmethode; U nweig hted M eansWilks lambda= ,91818, F (4, 4306)= 46,943, p= 0,0000

Effective hypothesis decompositionVertical bars denote 0,95 confidence intervals

staand want dr ieling boomkor

Visser ijmethode

6,00

6,02

6,04

6,06

6,08

6,10

6,12

6,14

6,16

6,18

6,20

6,22

6,24

pH

gill & ent. otter trawl beam trawl

Otter BeamGill & ent

pH and rigor mortis in whiting

6

pH Rigor mortis

Visser ijmethode; U nweig hted M eans

Wilks lambda= ,75060, F (4, 2716)= 104,73, p= 0,0000

Effective hypothesis decomposition

Ver tical bars denote 0,95 confidence intervals

staand want dr ieling boomkor

Visser ijmethode

6,30

6,35

6,40

6,45

6,50

6,55

6,60

6,65

6,70

6,75

6,80

pH

gill & ent. otter trawl beam trawl

Otter BeamGill & ent

Injuries

7

Visser ijmethode; U nweig hted M eansWilks lambda= ,91818, F (4, 4306)= 46,943, p= 0,0000

Effective hypothesis decompositionVertical bars denote 0,95 confidence intervals

staand want dr ieling boomkor

Visser ijmethode

0,2

0,3

0,4

0,5

0,6

0,7

0,8

0,9

1,0

1,1

1,2

1,3

IIM

gill & ent. otter trawl beam trawl

sole

V is s eri jm e th ode ; Un we igh te d Me a n s

W i l ks lam b d a=,7 50 60 , F(4 , 27 16 )=1 04 ,7 3 , p=0 ,0 0 00

E ffe c tive h yp oth e s is de c om po s i tion

V e rtic a l b a rs de n ote 0 ,9 5 c o n fi de n c e in te rva ls

s ta an d wa n t drie l in g bo om kor

V i s s e ri jm e thod e

0,4

0 ,6

0 ,8

1 ,0

1 ,2

1 ,4

1 ,6

1 ,8

2 ,0

IIM

gill & ent. otter trawl beam trawl

whiting

Mortality

8

sole whiting

Otter trawl 9% 7%

Beam trawl 60% 100%

Gill & ent.nets 15% 100%

TVB-N and QIM (shelf life studies)

9

0 5 10 15 20 250

5

10

15

20

25

30

sole

gill & ent. netsLinear (gill & ent. nets)Linear (gill & ent. nets)beam trawlLinear (beam trawl)Linear (beam trawl)otter trawl

Shelf life on ice (days)

QIM

0 5 10 15 20 250

5

10

15

20

25

30sole

gill & ent.netsbeam trawlotter trawl

shelf life on ice (days)

TVB

-N (m

gN%

)

TVB-N and QIM (shelf life studies)

10

0 5 10 15 20 250

5

10

15

20

25

whiting

max. shelf lifebeam trawlLinear (beam trawl)Linear (beam trawl)Linear (beam trawl)otter trawlLinear (otter trawl)Linear (otter trawl)Linear (otter trawl)Linear (otter trawl)Linear (otter trawl)

Shelf life on ice (days)Q

IM

2 4 6 8 10 12 14 16 18 2005

1015202530354045

whiting

beam trawl

otter trawl

Shelf life on ice (days)

TVB-

N (m

gN%

)

Conclusions

11

Sole : Gill& ent.nets trawling is less stressful than beam and otter trawling Less injuries with gill& ent.nets trawl, followed by beam trawl Few mortality with otter trawl and gill & ent. nets trawl Shelf lifebeam trawl < shelf lifeotter trawl < shelf lifegill&ent.nets

Whiting : Gill& ent.nets trawling is less stressful Significant more injuries with otter trawl Few mortality with otter trawl Shelf life: no significant difference between beam & otter trawl

Changing trawling methods promotes better quality and contributes to more sustainable fisheries

Sequid device: principle

12

XXXXXXXX

------------------

Objective alternative for QIM? (fish auction/ evaluation of catching methods in terms of fish quality)

Tested species: sole and plaice Technology: diëlectric spectroscopy TDR-measurements

Sequid device: principle

13

Sequid device : TDR measurement => Statistical PCA analysis Fourier transformation

Sequid device: results

14

Measurements RMSE (sole) Measurements RMSE (plaice)

Dark skin side 2.3 days Dark skin side 2.1 days

White skin side 2.1 days White skin side 1.7 days

Deskinned 1.5 days Deskinned -

Fillets 1.4 days Fillets 1.6 days

Sequid device: conclusions

15

R²: 70% → 82% RMSE with skin > RMSE deskinned

RMSE dark skin > RMSE white skin

> RMSE fillet

Experiments: tagged samples => reality = more complex!

Need for optimization of hard- and software for sequid device