Fish Hatchery Techniques: Quality Fingerlings for Offshore Aquaculture

1. Fish Hatchery Techniques: Quality Fingerlings for Offshore Aquaculture Michael Rust Northwest Fisheries Science Center Seattle, Washington

2. Outline • What is quality from the Hatchery? • Healthy fish • Weaned to Pelleted Feeds • No defects • Uniform Size • Physiologically appropriate

3. Healthy Fish • Goal: Fish should be free of known diseases • Approach - SPF hatcheries • Goal: Fish should be protected from potential diseases • Approach: • Vaccination • Nutrition

4. Automatic Vaccination Lines

6. Fish Weaned to Pelleted Diets • Goal: Fast Growth • Goal : Uniform Size • Goal: Cost Effective Feeding • Goal: Reduce Environmental Impacts • Goal: Healthy Fish • Approach - Wean fish early and completely in Hatchery • Approach - Complete Compound Feeds • Approach - No Wet Fish (Trash Fish) Diets

7. No Defects • Goal : High Product Quality • Approach - In Hatchery Provide Optimal Environmental Conditions • Approach - Provide high quality diets

9. Developmental Anomalies (Temperature) 100% 75% Other Jaw Total hatch 50% Spine Normal 25% 0% 6 9 12 Temp (oC)

10. Developmental Anomalies (Salinity) 100% 90% 80% 70% Other 60% Jaw Total hatch 50% Spine 40% Normal 30% 20% 10% 0% 15 20 25 30 35 Salinity (ppt)

11. Uniform in Size • Approach - Start with uniform graded fish • Approach - Genetic Selection for Uniform High Growth. • Approach - Completely weaned to High Quality Pelleted diets. • Goal: Uniform Product at Harvest

12. Physiologically Appropriate • Goal - Excellent Growth and Survival under conditions in Offshore cages. • Perhaps lower Oxygen • Perhaps stronger currents • Approach - Species Selection • Bioenergetics model under conditions likely to be found at site.

13. Simple Bioenergetics Model E = G + R + L • Where: • E is the total energy taken in by the fish from the diet • G is the amount of energy going into growth • R is the amount of energy used for everything that is not growh (movement, fighting diseases, reproduction, etc) • L is the losses due from Feces, Urine and energy to digest the feed (SDA)

14. Energy use curves for wild Blue Rockfish showing energy partitioning. Female R F+U+SDA G DB 6 ♀ Total 5 4 3 • Growth (G) represents a very small part of the energy budget of wild animals. • Respiration (R) and Waste (F+U+SDA) represents a large portion of the energy budget • Growth in farmed salmon can reach 50% of the total energy budget 2 1 Yearly energy demand (MJ) 0 0 5 10 15 20 25 30 ♂ Male 6 5 4 3 2 1 0 0 5 10 15 20 25 30 Age (years)

15. Need to develop a simple bioenergetics model for species of interest in off shore aquaculture • Conditions off shore are likely to be different than near shore. In Washington State it is likely that they will have: • Lower Oxygen • Higher Currents than traditional near shore aquaculture areas used by the salmon farming industry. Potentially more energy will be needed for R making less available for G. The cost/benefit to G from increased/reduced R is likely to be different among species The cost/benefit to G from increased/reduced R is likely to be different among sites.

16. Bioenergetics models can be developed for different conditions and species using respirametry Flow DO out CO2 out Flow DO in CO2 in By measuring the uptake of Oxygen under various conditions you can determine R and predict G

17. Summary • What is quality? It’s • Healthy fish • Weaned to Pelleted Feeds • No defects • Uniform Size • Physiologically appropriate

18. Thank you