Investigating growth rates and condition of Norwegian Spring Spawning Herring 0-age group juveniles across multiple nursery grounds

Supervisory Team:

Primary supervisor: Dr Valeriya Komyakova

Co-supervisor: Dale Maschette

Additional supervisors: Dr Olav Kjesbu, Institute of Marine Research, Bergen, Norway

Brief project description:

Norwegian spring spawning herring (NSSH) represents the largest herring stock in the world, that caries significant commercial importance. It is a member of the stock complex of Atlantic herring (Clupea harengus L.), a cold-temperate, pelagic schooling species. NSSH spawns along most of the Norwegian coast (58-69˚ N) from late February to early March. The eggs are deposited onto hard bottom substratum at the depth down to 250 m. The larvae hatch 2-3 weeks after spawning and drift with the Atlantic water currents towards Barents Sea where they remain for the following 3-6 years before joining the adult stock.

While large portion of the NSSH population resides in the Norwegian Sea, relatively isolated populations are also present in the fjords as well. As such, fjords do act as nursery grounds for some of the NSSH juveniles. It has been demonstrated that growth rates may differ significantly between the fjords. However, little is known about growth rate differences for 0-age group juveniles between the fjords and the Barents Sea. Similarly, little is known about fitness of individuals occupying different nursery grounds along the long Norwegian coast. As such, this project will evaluate the differences in the 0-age group juveniles growth rates and fitness between different spawning areas, fjords and the Barents Sea.

Principal research question: Will early life stages from northern or fjord components of NSSH do better in terms of growth and survival prospects in a warming ocean?

Skills students will develop during this research project:

• Juvenile fish otolith preparation for growth rates measurement
• Growth rates measurements using fish otolith
• Data analysis