1. Projected changes to freshwater aquaculture
Presented by
Timothy Pickering

2. Authors
This presentation is based on Chapter 11 ‘Vulnerability of aquaculture in the tropical Pacific to climate change’ in the book Vulnerability of Tropical Pacific Fisheries and Aquaculture to Climate Change, edited by JD Bell, JE Johnson and AJ Hobday and published by SPC in 2011.
The authors of Chapter 11 are: Timothy D Pickering, Ben Ponia, Cathy A Hair, Paul C Southgate, Elvira S Poloczanska, Luc Della Patrona, Antoine Teitelbaum, Chadag V Mohan, Michael J Phillips, Johann D Bell and Sena De Silva

3. Plans to greatly increase future production and livelihoods from freshwater aquaculture will stay on track, despite climate change.
Freshwater aquaculture for food security and livelihoods will itself be an adaptation to the effects of climate change on coastal fisheries
Freshwater aquaculture in the SW Pacific will generally benefit from climate change

4. 1. Current and projected freshwater aquaculture production

5. Food security
Culture of lower-value fish for food security is gaining higher priority
Drivers are increasing populations, and a general decline in the coastal fisheries with which small Pacific islands were once blessed.

6. Small-pond aquaculture is one of three major strategies now being proposed, along with: - low-cost inshore FADs -increased local landings of the region’s tuna catch.
Small-pond aquaculture will be least in quantity
But greatest in quality (freshness, nutrition) and availability (right on the doorstep of inland households)

7. Tilapia/carp for Food security, Livelihoods
Cage-culture
Highlands
Lake restocking to replace mossambicus with niloticus
Carp/tilapia
PNG
Trout/tilapia
Highlands
10-15,000 fish farms

8. Tilapia for livelihoods
Semi-intensive culture in earthen ponds
Lined ponds
Aquaponics
Red Tilapia – Cage Culture
Intensive
Recirculating
Intensive flow-through

9. Milkfish for food security
Brackish ponds
Freshwater ponds
Livelihoods
Cage culture for food, tuna-bait

10. Freshwater prawn Macrobrachium
Hatchery-based culture
Macrobrachium rosenbergii
Capture-based culture
Macrobrachium lar
Integrated taro/prawn pond culture
Monoculture

11. SME approaches to food security
Small household level aquaculture for subsistence consumption is only viable with on-going government support and subsidy of farm inputs, but is viewed as important by PICTs
Inland aquaculture for livelihoods also contributes to food security
The next challenge is to add a layer of viable SME-scale commercial-market aquaculture for peri-urban markets

12. Tilapia It is very difficult to estimate tilapia production in PICTs
There are many small-scale farmers in very remote places
There are repeated small harvests from each pond, without weighing

13. Tilapia Fiji harvests fluctuate around 100 - 300T
PNG reports 100T per year to FAO, but this is a big under-estimate
Tilapia aquaculture continues to expand in the region
Samoa now has 25 farms
Solomon Islands has begun an Inland Aquaculture project to support emerging farmers
A tilapia hatchery has been established on Santo in Vanuatu

14. Livelihoods
Tilapia
Tilapia

15. Milkfish 30 – 80 T per year produced in intensive systems in Guam
5 – 15 T per year is produced in Kiribati
Four farms now operate in Palau
Capture-based culture trials are underway in Fiji, Solomon Islands and Tonga

16. Freshwater prawn FW prawn farming in Fiji produces about 25 T per year
Vanuatu has now established a FW prawn hatchery
Other PICTs are interested (PNG, Cook Islands).
PICTs could produce several hundred T per year in total

17. 2. Vulnerability of freshwater aquaculture

18. Projected changes
Source: Lough et al. (2011), Ganachaud et al. (2011)

19. Temperature Spatial variation in temperature increase 2035 2050* 2035
2100
* Based on B1 2100
Source: Lough et al. (2011)

20. Rainfall Spatial variation in rainfall (winter) 2035 2100
Source: Lough et al. (2011)

21. Greater climatic variation
Extremes will become more extreme
Expect the unexpected! (Droughts, too)
Flows in Tontouta River, New Caledonia, after cyclones
Source: Gehrke et al. (2011)

22. Tilapia, freshwater prawn
Tilapia aquaculture in the Pacific will not be particularly vulnerable, and may benefit from future climate change
Temperatures suitable for tilapia and prawn farming will be extended to higher latitudes and higher altitudes.

23. Tilapia, freshwater prawn
DFF (Fiji) Ltd Prawn Farm
Higher rainfall means the amount of habitat and water available for inland aquaculture will increase
Some areas with increased rainfall or cyclones may become more prone to flooding
Cyclone Mick, December 2009

24. Tilapia, freshwater prawn
Water column stratification from higher temperatures creates a de-oxygenated bottom layer in ponds. Fish are crowded and prawns die, unless energy is expended on pond aeration.
Higher temperatures by 2100 may cause heat stress on prawns, and increase prevalence of pathogens causing disease

25. Milkfish
Increased temperatures will extend the geographical range of milkfish breeding, and extend the season of fry collection for pond stocking
Milkfish breed in seawater, so supply of fry is at risk from ocean acidification

27. 3. Key responses and adaptations

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

29. How should we respond?
Prepare to increase flushing and aeration to combat stratification and lower oxygen due to warmer temperatures and higher rainfall
Photo: Jacques Patrois

30. How should we respond?
Develop inland aquaculture industries based upon freshwater species, for food security and livelihoods, and for adaptation to the effects of climate change
[But avoid spread of alien fish species to areas of high conservation value]

31. 4. Outlook for freshwater aquaculture

32. Outlook
Aspirations for significant future production ( T per high-island PICT) and livelihoods (between 10,000 to 20,000 persons part-time) from inland aquaculture are still likely to be realised.

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

34. Thank you