Presentation PhDresearch Drs Ir Maarten Soetaert UGhent ILVO 2 Content Safety Margin for a selection of marine species Determine the injury dose ID 50 Determine the lethal dose LD ID: 411043
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Slide1
SG Electra Presentation PhD-research
Drs. Ir Maarten SoetaertUGhent - ILVOSlide2
2Content
‘Safety Margin’ for a selection of marine species
Determine the injury dose (ID
50)
Determine the lethal dose (LD
1
0)
Optimalisation
of startle pulse for sole
At ≠ frequency, field strength, waveform, wavelength, pulse type
Effect of startle pulse for sole on marine species
Effect of electrical pulses on fish qualitySlide3
3Safety Margin (I): idea
Goal: determine the injury dose (ID) and lethal dose (LD) for a selection of marine organisms:
Sole: target species
Cod: top predator, sensitive to pulses
Shrimp: target species
Sandworm: model species for
polychetes
Starting from startle pulse for C
rangon
crangon
At 50 & 100 V/m: 5 Hz → 180 Hz
invertebrate
vertebrateSlide4
4Safety Margin (II):
What?
Injury Dose x% (
IDx
):
frequency at which x % of the exposed animals shows extra injuries
Lethal Dose x% (
LDx
):
frequency at which x % of
the exposed animals dies
In
this
example
:
ID25 = 25Hz
LD50 = 45 Hz
Slide5
5Safety Margin (III): How?
Homogeneous Field
Exposure
(3s
)
2 plate-shaped electrodes
Orientation:
Euthanasia after 14 days
Autopsy
Macroscopic: hemorrhages, color,
spots, deformation, …
Rontgen photos (lateral & dorsal)
Histology: dorsal muscle, kidney,
liver, spleen, intestine, gills, heartSlide6
6Safety Margin
(IV): Why?
What can we learn out of it?
Difference in sensitivity between 4 species
Effect of field strength on effects
(injury/mortality
)
Effect of frequency on effects (injury/mortality)
Kind of injuries function of frequency?
Is there a ‘safe’ range of pulse parameters in which we can apply pulses in justifiable way?
Pulses of
Hovercran
/
Pulskor
/
Pulswing
in safe zone?Slide7
7Content
‘Safe Zone’ for a selection of marine species
Determine the injury dose (ID
50)
Determine the lethal dose (LD
50)
Optimalisation
of startle pulse for sole
At ≠ frequencies, field strengths, waveforms, wavelengths, pulse types
Effect of startle pulse for sole on marine species
Effect of electrical pulses on fish qualitySlide8
8Startle
Pulse for Sole: idea
25 % of sole jumps out of sediment during exposure to startle pulse for
shrimp
(
Chiers
et al., 2011)
Is there a ‘safe’ startle pulse that makes the majority
of the sole jump out of the sediment ?
Varying different parameters: frequency, field strength, pulse form, pulse duration, pulse type
Chiers
et al., 2011, ‘Short-term effects of low frequency pulsed direct current on captive-housed sea fish’, submittedSlide9
9Startle
Pulse for Sole: parameters
Frequency:
Field strength:
Pulse form:
Pulse duration: 0,1 to 0,5
ms
Pulse type:
Time of exposure: 1 to 2 s
Within
Safety
MarginsSlide10
10Startle
Pulse for Sole: how?
Video tracking of reaction during exposure at specific pulse, quantification & comparison
Parameter
Effect score
(A)
Weight
(B)
Total
(T)
3
2
1
= A
x
B
1.
Hight upbove bottom
(cm)
> 15
5 - 15
< 5
3
T
1
2.
Swimming speed
(% of max)
< 75
25 - 50
< 25
1
T
2
3.
Recovery time
(s)
> 3
3 - 1
< 1
2
T
3
TOTAL “EFFECT NUMBER”
(=
assesment
number of observed startle response)
T
1
+ T
2
+ T
3Slide11
11Content
‘Safe Zone’
for
a
selection
of marine species
Determine
the
injury
dose (ID50)
Determine the lethal
dose (LD
50)Optimalisation
of
startle
pulse
for
sole
At ≠
frequency
, field
strength
,
waveform, wavelength, pulse type
Effect of startle pulse for sole on marine species
Effect of electrical pulses
on fish
qualitySlide12
12Startle
Pulse for Sole: Effects
Video tracking of reaction
after
exposure at optimal sole startle pulse
Feeding response
Behavior
Euthanasia & autopsy (
cfr
ID &
LD):
Macroscopic
Rontgen photos
Histology
s
ole
&
c
od
s
ole
&
cod
s
hrimp
&
sandwormSlide13
13Content
‘Safe Zone’ for a selection of marine species
Determine the injury dose (ID
50)
Determine the lethal dose (LD
50)
Optimalisation
of startle pulse for sole
At ≠ frequency, field strength, waveform, wavelength, pulse type
Effect of startle pulse for sole on marine species
Effect of pulses on fish qualitySlide14
14Effect of
pulses on fish quality
Is there an effect on the sole quality?
≠
in appearance?
Pulse fisherman is getting a better price: why?
What/how big is the difference with beam trawl?
≠
in filet quality?
Do electric pulses have an effect on fish decay? (QIM)
f.e
. faster or slower decay
≠
in filet taste?Slide15
Thanks for your attention!
Questions?