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Hardangerfjordseminaret 2014
Thon Hotel Sandven, Norheimsund, 21. november
Media skriver: “Lakselusmedisin
tar knekken på rekene”
– Stemmer det?
Resultater fra prosjektet “FLUCLIM - Effects of diflubenzuron on Northern shrimps
(Pandalus borealis) at ambient and future climate conditions”
IRIS Biomiljø
Lab-team: Renée K. Bechmann, Shaw Bamber, Emily Lyng,
Stig Westerlund, Sree Ramanand, Marianne Nilsen
Elisa Ravagnan - Modelling
NIVA
Katherine Langford – Analysis of DFB
Jannicke Moe & Dag Ø. Hjermann - Modelling
University of Leicester
Paul Seear – Genomics
Université du Québec à Rimouski
Piero Calosi – Scientific advisor
Finansiert av Forskningsrådet
Havet og Kysten (2014-2016)
Markus J. Thonhaugen
nrk.no
The Problem ….. The envirnomental Challenge
Ambient
climate
pH 8.1
7C
Future climate
Ocean acidification (pH 7.6) and
increased temperature (10C)
Shrimps
Pandalus borealis
Diflubezuron
from medicated fish feed
Log Kow 3.8
A chitin
synthesis
inhibitor
Benzoylurea
pesticide
Anti-parasitic drug
against salmon lice
Controls: Normal fish feed
Shrimp larvae are exposed to DFB
from suspended particles +
dissolved DFB:
Negative effects?
How can shrimps be exposed?
14 days treatment of
salmon to get rid of
salmon lice
Medicated
fish feed
Positive effect
for salmon:
Salmon lice die
during moulting
(Re)suspended particulates
Dissolved DFB from fish feed
Experiment done spring 2014
Pilot test spring 2014
Main experiment next year
Adult shrimps eat feed waste, feces
and sediment:
Negative effects on non-target
epibenthic crustacean?
Feed waste
Feces from salmon
Sediment
Continuos flow exposure system
10°C
Temperature
controlled seawater
Heat exchangers
7°C
+ CO2
Aqua Medic
system
Pressure regulator
Connection
plug
C
Solenoid valve
CO2
Stock solutions of sediment slurry with
medicated or clean fish feed
Main DFB exposure:
Medicated fish feed
(0.66 g DFB/kg)
2g
3.5 mm
pellets
Flow: 200 ml/min
A little extra DFB:
8% fish feed in sediment:
0.5 mg/L
Shrimp larvae were exposed to the
pellets for 2 weeks from hatching
Tr e a t m e n t s & T i m e :
Ambient Climate
DFB
DFB at Ambient Climate
Future Climate
DFB at Future Climate
DFB
-14
-7
0
7
14
21
7°C, pH 8.1
x6
7°C, pH 8.1
x6
10°C, pH 7.6
x6
10°C, pH 7.6
x6
28
Age of larvae (days)
Climate acclimation of shrimps
(females with embryos)
Hatching
Two weeks exposure to medicated pellets with DFB
Ambient climate: 7°C and
X6
pH 8.1
Exposure to
DFB
X6
Future climate: 10°C and
Exposure to
DFB
X6
X6
pH 7.6
200
200
200
200
X6
X6
X6
X6
batches
Control
batches
DFB
batches
OA/T
batches
OA/T + DFB
Analysis of DFB by Katherine Langford, NIVA
Total concentration of diflubenzuron in the aquaria
(dissolved and on particles)
1 mm mesh
0.2 L/min (288 L in 24 h)
After 4 hours: 2 µg/L
After 24 hours: 1 µg/L
1.32 mg DFB in
2 g pellets
Conc. of DFB
Fish feed after 24 h in the cylinder:
15 litre
3.5 mm pellets
Analysis of DFB by Katherine Langford, NIVA
Concentration of diflubenzuron after 4 h and 24 h
Total Concentration of DFB in the aquaria (mean + SE)
i.e. DFB attached to feed particles and dissolved in the water
µg/L DFB
3,0
2,5
2,0
4h
1,5
1,0
4h
0,5
0,0
n=3
24 h
n=3
Ambient Climate + DFB
24 h
n=3
n=3
Future Climate + DFB
Controls samples: <0.01 – 0.02 µg/L
DFB was analyzed at NIVA by liquid chromatography coupled to tandem mass spectrometry (LC/MS/MS)
S U RV I VA L fo r s h r i m p l a r v a e
Mean percent survival for 6 replicate batches of shrimp larvae exposed to DFB at two climate scenarios
Percent survival of shrimp larvae
100
80
Ambient Climate Control
- 25 %
Future Climate Control
60
- 56 %
40
Ambient Climate + DFB
20
- 82 %
Future Climate + DFB
Exposure to DFB or
clean pellets
0
0
5
10
15
Days post-hatch
20
25
30
Development time (zoeal progression) for shrimp larvae
The tail of the shrimp larvae change when
they develop from stage II – III - IV
Photo: Tandberg & Arnberg
Stage I zoea
Stage II zoea
Stage III zoea
Stage IV zoea
Time
Shrimp larvae go through five pelagic zoea stages and one megalopa stage before they settle as post-larva
We followed them until stage 4
L A RVA L D E V E LO P M E N T T I M E f o r t h e s u r v i v o r s
% stage II
% stage IV
% stage III
100
0
No stage III
No stage II
No stage IV
DFB
Control
20
DFB
40
Control
60
Control
Ambient
Climate
DFB
80
100
80
0
Day 6
Day 9
Day 13
Exposure to medicated (DFB)
or clean (control) pellets
Day 17
DFB
Control
DFB
Control
DFB
Control
DFB
20
Control
40
DFB
Future
Climate
Control
60
Day 19
Day 27
Day no = age of
shrimp larvae
1 litre
Feeding rate
for stage II and IV larvae
5 shrimp larvae and
150 Artemia nauplii
in 1 litre seawater.
Pandalus borealis larvae
Wait 5 hours.
Count remaining Artemia.
Artemia nauplii
Feeding rate for the survivors
Stage II zoea
Stage IV zoea
6
Number of Artemia eaten per
shrimp larvae per hour
Number of Artemia eaten per shrimp larvae per hour
Control
Control
5
DFB
DFB
4
Control
Control
3
No stage 4,
these are
stage 3!
DFB
2
DFB
1
0
Ambient
Climate
1
2
Future
Climate
3
4
Ambient
Climate
5
6
code B
Future
Climate
7
8
Shaw Bamber, IRIS
BST
«Bamber ’s Swimming Test»
Light
IR light
Detector
Shrimp larvae are
photo-positive
(they swim towards the light)
- Will DFB affect
swimming activity at
ambient or future
climate conditions?
Shaw Bamber, IRIS
Swimming activity
Future Climate
Ambient Climate
•
Similar swimming activity
for control and DFB
exposed STAGE I and II
larvae.
•
STAGE I: Similar swimming activity for control
and DFB exposed larvae.
STAGE II: Lower swimming acitivity for DFB
exposed larvae than control larvae.
STAGE I:
Before first moult
STAGE II:
Those that survived first moult
Control
(future climate)
DFB
(future climate)
Example - Raw data
Conclusions from the shrimp larvae experiment
DFB medicated pellets caused high mortality of
shrimp larvae and negative effects on the surviving
larvae
More mortality and more negative effects on the
survivors at future climate
- What about the adult shrimps?
- Are they more tolerant to DFB?
Pilot experiment
Effect of DFB exposure on post-hatch moulting
• Shrimps in large tanks and in 15 litre aquaria
• Exposed to a few grams of medicated or clean
fish feed in the water for 2-4 weeks
Upubliserte resultater fra HAVKYST prosjekt #234407/E40.
Prosjektleder: Bechmann, IRIS Biomiljø.
Pilot experiment
Control shrimps moulted successfully in the
lab a few weeks after all eggs had hatched
Shrimp exit
Pilot experiment
Pilot experiment
Shrimps died during moulting when exposed to medicine
pellets containing DFB (diflubenzuron)
Flubenzurones are chitin synthesis inhibitors:
they stop the organism from casting its exuvium
during the molting process resulting in death.
Exposed to a few grams of medicated
fish feed in the water for 2-4 weeks
The Score
Controls – DFB exposed
Successfull moults:
14
Dead of unknown cause:
Dead during moulting:
vs
-
0
1
-
3
0
-
13
Oppsummering!
Medisinfôr med
flubenzuroner
Rekelarver og andre krepsdyr i planktonet
kan få i seg dette…
Rekelarver er veldig følsomme for
diflubenzuron fra medisin-fôr!
Fôr - spill
Strømmen tar med seg
rester av medisin-fôr,
feces og forurenset
sediment
Voksne reker kan spise dette og få problemer
under skallskiftet
Lite metaboliseres
Alt skilles ut raskt
Feces med flubenzuroner
Flubenzuroner har «lang holdbarhet»
i det marine miljø
Konklusjon!
Både rekelarver og voksne reker dør under skallskifte når de utsettes for
medisin-fôr med diflubenzuron
Mer negative effekter ved høyere temperatur (framtidig klimascenarie)
Så svaret er:
Ja! Lakselusmedisin kan ta
knekken på rekene hvis for mye
slippes ut i fjordene våre.
- So what?
- Kan vi både beskytte ville krepsdyr og laksens helse?
?
- Bør vi bruke «føre-var-prinsippet» hvis vi er usikre på hvor mye
flubenzuroner lokale krepsdyrpopulasjoner tåler? Eller bør vi forske
mer?
- Kan vi kun bruke andre metoder enn pesticider for å kvitte oss med
lakselus …. mens vi venter på lakselus-vaksinen til Frank Nilsen & co?
…. eller i hvert fall droppe pesticider med lang holdbarhet og høy
toksisitet for ville krepsdyr?
Please!
On-going project work:
Genomics
The aim is to develop a genetic marker for exposure to chitin synthesis inhibitors in shrimps
Paul Seear is working with the shrimp genomics
Future(2015) project work:
Main experiment with adult shrimps
Future(2016) project work:
Elisa Ravagnan
Jannicke Moe &
Dag Ø. Hjermann
Modelling
…. analyse the multiple stressors impacts of
increased temperature and OA together with
DFB exposure on Northern shrimp populations
Takk til dere som hørte på!
Thank you for the money:
NFR
HAVKYST
Thak you for the science:
Partners
The local crowd
Photo: Elisabeth Tønnessen
Stig Westerlund
Emily Lyng
Shaw Bamber
Elisa Ravagnan
Marianne Nilsen
Sreerekha S. Ramanand
Renée K. Bechmann
Katherine Langford,
Jannicke Moe
Dag Ø. Hjermann
University of
Leicester
Paul Seear
Université du
Québec à Rimouski
Piero Calosi
More info:
[email protected]