Projected changes to aquaculture

1. Projected changes to aquaculture

2. Based on…….

3. Outline • Freshwater aquaculture (tilapia, milkfish, freshwater prawn) • Vulnerability of freshwater aquaculture • Coastal aquaculture/mariculture (giant clams, corals, trochus, sea cucumbers) • Vulnerability of coastal aquaculture

4. Tilapia Food security • Lake restocking to replace Mossambique Tilapia with Nile Tilapia • PNG 10-15,000households with tilapia farms

5. Tilapia Livelihoods • Cage culture • Semi-intensive ponds • Aquaponics • PNG - 10-15,000households with tilapia farms

6. Tilapia • Tilapia farming is expanding in the region • Samoa has 35 farms • Fiji produces 200-300 tonnes per year • Solomon Islands has begun an Inland Aquaculture project to support emerging farmers • A tilapia hatchery has been established in Vanuatu

7. Milkfish • 30 – 80 t per year in Guam • 5 – 15 t per year in Kiribati • Four farms in Palau • Capture-based culture trials in Fiji, Solomon Islands and Tonga Brackish ponds Freshwater ponds Cage culture for food, tuna-bait

8. Freshwater prawn Macrobrachium • Hatchery-based culture (M. rosenbergii) • Capture-based culture (M. lar) • Fiji produces about 25 t per year

9. Vulnerability of freshwater aquaculture

10. Tilapia, freshwater prawn • Likely to benefit from climate change • Higher rainfall and warmer temperatures will allow farming in more places and at higher altitudes.

11. Tilapia, freshwater prawn • Some areas with increased rainfall or cyclones may become more prone to flooding DFF (Fiji) Ltd freshwater prawn Farm Cyclone Mick, December 2009

12. Tilapia, freshwater prawn • Stratification from higher temperatures causes de-oxygenation – aeration needed

13. Milkfish • Increased temperatures will extend the geographical range and season of fry collection • Risk from ocean acidification?

14. How should we respond? • Build fish ponds to avoid more severe floods Photo: Avinash Singh

15. How should we respond? • Increase aeration to combat stratification

16. Conclusion • Freshwater pond aquaculture is likely to be favoured by climate change Source: Pickering et al. (2011)

17. Coastal aquaculture

18. Annual value • Pearl and shrimp farming dominate • Comprise >90% of total value

19. Livelihoods Shrimp Pearl

20. Restocking Sea cucumber Giant clam Trochus Green snail

21. Vulnerability of mariculture

22. Marine fish, shellfish • Mariculture of fish and shellfish faces major uncertainties • Possible effects of acidification on larval fish and shells Applies to giant clams and cultured corals

23. Aquatic animal diseases • Higher temperature are likely to increase prevalence of pathogens • The nature and extent of future disease risks are not clear White Spot Virus WSV

24. Adaptations • Grow ornamentals at greater depth (cooler waters) • Identify sites where CO2 is reduced • Selective breeding for resilience to acidification

25. See Chapter 11 for vulnerability of pearl oysters, shrimp, seaweed and other commodities

26. Conclusion • Mariculture has development potential in years ahead • But production efficiency is likely to be progressively affected by climate change