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!