1. Operational fish larval drift modelling Bjørn Ådlandsvik og Frode Vikebø Institute of Marine Research Opnet meeting, Geilo, 14-15 May 2008

2. Why larval drift modelling Study recruitment processes in fish stocks  Prediction  Effects of climate variability Basis for biological Individual Based Models  Larval behaviour in the vertical  Growth  Survival

3. Why operational Fish eggs and larvae are vulnerable to oil spill accidents  A year class of a major fish stock is worth GNOKs Useful information for fish larval surveys Useful information for sea bird research...

4. How? Particle tracking  Lagrangian Advection and Diffusion model, LADIM Start from knowledge of typical spawning areas Include simple Individual Based Model  Vertical movement  Temperature dependent growth

5. Operational requirement Consistency requirement for oil spill overlap analysis: Fish larvae and oil transport must be forced from the same regional ocean circulation model  Otherwise exposure will be controlled by different current patterns

6. Difference from oil drift models Oil drift:  Usually know initial condition time and location of oil spill Larval drift:  Knowledge of typical spawning areas and times Longer simulation time Can be reinitialized if more information becomes available

7. Practical implementation Daily download operational ocean model forecast (Nordic4km) from met.no to IMR Append to a current and hydrographic archive Rerun the offline larval drift simulation from spawning/hatching Make plots and put the results on a web site  Presently: http://www.imr.no/~bjorn/oplarve

9. Cod from Møre

10. Cod from Moskenesgrunnen

11. Cod from Malangsgrunnen

12. Total cod larvae distribution

13. Total herring larvae distribution

14. Vertical behaviour for herring larvae Day: 5-20 m, Night: 20-40 m Vertical swimming speed up to 1/6 bodylength per second Combination of a deterministic and a random component

15. To do Improve the design of the web site  Now home made, get help from info dep. Give the web site a more prominent (and permanent) URL at www.imr.nowww.imr.no Implement larval drift into operational model suite at met.no  24/7 operational organization  More frequent updates of current forcing