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Effects of fishing gear on quality – The SEAQUID-EFF project. Daphné Deloof Karen Bekaert, Johan Robbens. 01/10/2013 Fishing gear and effective catch handling workshop 2013. Institute for Agricultural and Fisheries Research Animal Sciences Unit www.ilvo.vlaanderen.be - PowerPoint PPT Presentation
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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
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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
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