CHALLENGES IN THE REARING OF EUROPEAN HAKE MERLUCCIUS
MERLUCCIUS
AUDREY J. GEFFEN, ANNE-LAURE GROISON, LENE KLEPPE, University of Bergen, Norway. HÉLÈNE du PONTUAL, AURELIE JOLIVET, Ifremer, STH/LASAA, Brest, France.
RAGNAR SALTE, MerluNor, Brekke / Norwegian University of Life Sciences, Ås, Norway.
Department of Biology
Fisheries ecology and Aquaculture
Why Hake? – Good marketing
opportunities
Interesting biology
Why in Norway? – Good technical foundation, Good access to local wild
populations
Short history of hake larval rearing 1997, 1998, 1999 - Reidun Bjelland and Anne Berit Skiftesvik
(Institute for Marine Research– Austevoll Research Station) Bjelland & Skiftesvik 2006
2005 – Anne Laure Groison (Department of Biology, UiB)– Ragnar Salte (Department of Animal and Aquacultural
Sciences, Norwegian University of Life Sciences) establishes MerluNOR and captive broodstock
2006 – Anne Laure Groison (UiB), Aurelie Jolivet
and Hélène du Pontual (Ifremer, Brest)
2007 – Natural Spawning!!!! MerluNor and Ifremer– Aurelie Jolivet and Hélène du Pontual (Ifremer, Brest)– Audrey Geffen (UiB)
2008 – Natural Spawning at MerluNOR - UiB
Status and challenges
• One captive broodstock• One instance of successful rearing• Larval rearing until 25dph, past first feeding
Technical Challenges
Biological Challenges
Photos: J. Skadal
Technical Challenge -1
Eggs have been obtained by stripping wild-caught fish
Captive spawning
Captive populations established at Brest, France and at Brekke, Norway
Egg production in both populations
Fertilized eggs leading to larvae produced by Brekke group
MerluNor – Brekke, Norway
Egg production
Captive spawning pattern compares well with field data
Spawning first observed at Brest and at Brekke in 2007
2 Females at Brekke produced 17 batches in 2007, 3 batches so far in 2008
Photo: J. Skadal
23-Jun 7-Jul 21-Jul 4-Aug 18-Aug 1-Sep 15-Sep 29-Sep
Em bla : 9 batches (26 June - 5 Sept)
Hera: 8 batches (11 July - 29 Sept)
Photo: J. Skadal
Technical Challenge -2
Photo: J. Skadal
Biological Challenges – 1: Growth Pattern
Hatching – Day 0
0 5 10 15 20 25 30 35 40
A ge (dph)
2
4
6
8
10
La
rva
l Len
gth
(m
m)
Palom era et a l. 2005A lvarez & Cotano 2005Bergen 2007Brest 2007B jelland 2001
0 5 10 15 20 25 30 35 40
A ge (dph)
2
4
6
8
10
La
rva
l Len
gth
(m
m)
Bergen 2007Brest 2007B jelland 2001
0 5 10 15 20 25 30 35 40
A ge (dph)
0
0.02
0.04
0.06
0.08
0.1
0.12L
arv
al D
ry W
eig
ht
(mg
)
Bergen 2007Brest 2006B je lland 2001
2 3 4 5
Larval Length (mm)
0
0.02
0.04
0.06
0.08
0.1
0.12
La
rva
l Dry
We
igh
t (m
g)
Alvarez & C otano 2005Bergen 2007Brest 2006B jelland 2001
Biological Problems – 2:
3 Dph
10 Dph
12 Dph
Establishment of feeding
Photos: J. Skadal19 Dph
0 10 20 30
Number of hake larvae
200
160
120
80
40
0
De
pth
(m
)
0 100 200 300 400µmol s-1 m-2
Challenges?
Broodstock, Incubation
Feeding: Prey size, swimming behaviour
Rearing conditions: light levels
Coombs & Mitchell, 1982
Light levels In tanks ~ 2-5 µmol s-1 m-2
At surface 8 - 15 µmol s-1 m-2
Thanks!