E N D
CHALLENGES IN THE REARING OF EUROPEAN HAKE MERLUCCIUS MERLUCCIUSAUDREY 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
Photo: J. Skadal 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 Technical Challenge -2
Photo: J. Skadal Biological Challenges – 1: Growth Pattern Hatching – Day 0
Biological Problems – 2: Establishment of feeding 3 Dph 12 Dph 10 Dph 19 Dph Photos: J. Skadal
Challenges? Broodstock, Incubation Rearing conditions: light levels Feeding: Prey size, swimming behaviour Coombs & Mitchell, 1982 Light levels In tanks ~ 2-5 µmol s-1 m-2 At surface 8 - 15 µmol s-1 m-2