August 30, 2007

 

International research project aims to solve cod breeding puzzle

 

 

Scientists are undertaking studies on spawning behaviour on cods to determine why certain cods can spawn and breed while others do not.

 

The project was financed by the EU regional periphery programme with contributions from Norway, UK, Iceland and Russia.

 

The puzzle, if solved, could bring immense benefits for hatcheries in terms of productivity and efficiency. North Cod, a project in Norway, aims to solve that puzzle. 

 

Dr Oddvar Ottersen, North Cod project leader based at Bodo University in Norway, thinks the behaviour could be a natural response to food resources or population density.

 

The project would also study the freezing of cod sperm for preservation.

 

Trials so far have yielded 80 percent fertilisation rates and similar success with hatched larvae survival.

 

The project has found that egg quality drops as the spawning season, from February to April, progresses. Peak productivity is mid-term, when spawning rate and the number of viable eggs produced increases. The scientists are hoping to use this knowledge to better identify prolific fishes.

 

The project has also explored DNA typing and genetic marking so that future selection programmes could improve the hybrid vigour and breed potential of farmed cod genotypes.

 

Although the project remains in its early stages, much of the technology learned from salmon farming could apply to that of cod.

 

However, raising brood stock and fry, is much more difficult than that with salmon. The hatchlings and developing fry are extremely small compared with salmon and need conducive environments.

 

The research team has produced a hatchery production manual with details on recommended management practices and the contents would be available online within the year.