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Projected changes to mariculture. Presented by Timothy Pickering. Authors.
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Projected changes to mariculture Presented by Timothy Pickering
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
Mariculture (marine aquaculture) already makes a significant contribution to some PICT economies • It has unrealised potential in other PICTs • But future plans could be de-railed by projected climate changes.
Marine finfish Batfish (P. orbicularis) Barramundi Grouper (Serranidae)
Edible Oysters Mudcrab
Culture-based fisheries: Invertebrate re-stocking Sea cucumber Giant clam Trochus Green snail
Annual value of aquaculture in PICTs • 2007 total value US$ 211 million • Pearl in French Polynesia is dominant • Next is shrimp in New Caledonia • These two make up over 90% of total value Annual value of aquaculture commodity production
Livelihoods Shrimp Pearl
Contribution of aquaculture value toward GDP • Aquaculture contributes 22% of fisheries contribution to GDP in PICTs Annual percentage contribution of fisheries and aquaculture sectors to Gross Domestic Product in PICTs
Projected production without climate change • Value of PICT aquaculture in 2007 it was USD 211 million (Ponia 2010) • If no climate change, is “optimistically”* forecast to be to be worth USD 320 million by 2025 * Though note recent SPC report ‘Opportunities for the Development of the Pacific Islands Mariculture Sector‘ • Growth mainly driven by expansion within the existing commodities, via adoption of these proven commodities by additional PICTs.
Projected changes Source: Lough et al. (2011), Ganachaud et al. (2011)
Ocean acidification Source: IPCC (2007), Ganachaud et al. (2011)
Temperature 2035 2050* Spatial variation in temperature increase 2035 2100 Source: Lough et al. (2011) * Based on B1 2100
Projected impacts • Mariculture faces major uncertainties • Mainly from lack of knowledge about the possible effects of seawater acidification on bone and shell formation • Pearl aquaculture will be more vulnerable to acidification than shrimp.
If projected changes in seawater pH adversely affect pearl larvae, adult pearl shell, or pearl quality, then this industry will be highly vulnerable to climate change. High-quality Fiji Pearls Poor lustre, defects
Pearl Hunter Pearls hatchery, Fiji Islands • The pearl industry is not vulnerable to, and may benefit from, other projected changes in climate such as sea level rise, provided farm structures do not become too exposed to heavy seas. • By 2100s seawater temperature may become problematic for larval survival in some locations. Storm surge during Cyclone Tomas, February 2010
Marine shrimp Now: • Pacific shrimp industries face both benefits and risks from climate change. • Climatic conditions for shrimp aquaculture in higher latitudes are likely to improve, subject to seasonal temperature instabilities in New Caledonia not becoming even more pronounced. Future: good Future: bad
Marine shrimp The main threats to shrimp culture stem from: • Acidification • Sea level rise • Scarcity of fishmeal • Pathogens.
Marine shrimp Now: crop in progress • Inundation of low-lying coastal lands, that make shrimp ponds impossible to drain dry, will have a huge impact on the New Caledonia shrimp industry Now: pond preparation Future: poor pond prep. Future: difficult to harvest
Kappaphycus seaweed Ice-ice • Kappaphycus seaweed is vulnerable to increased seawater temperature beyond 30oC • Lower coastal salinity due to higher rainfall can stress seaweed • These both cause “ice-ice” and Epiphytic Filamentous Algae (EFA) outbreaks • Reduced nutrient upwelling will slow seaweed growth EFA
Marine fish, shellfish • Mariculture of fish and shellfish faces major uncertainties. • Possible effects of seawater acidification on larval fish and shells
Aquatic animal diseases • Due to higher temperature, it is likely there will be an increase in the prevalence of pathogens affecting aquaculture commodities in this region • The nature and extent of future aquatic animal disease risks are not clear. White Spot Virus WSV
How should we respond? • Expect production losses from extreme events and ‘unexpected’ causes • Ensure that financial planning for enterprises can absorb such shocks Photos: Cathy Hair
How should we adapt? • Grow pearls at greater depth for final nacre Photo: Leanne Hunter Source: Pickering et al. (2011)
How should we adapt? • Long term data collection to identify sites where conditions for nacre growth may be better • Progressively switch to hatchery production Photo: Rusiate Vadiga
How should we adapt? • Build new shrimp ponds where drainage will not be affected by sea level rise Source: Pickering et al. (2011)
How should we adapt? Move shrimp ponds landward or to higher ground Adopt more intensive farming methods that use less land and water Source: Pickering et al. (2011)
How should we adapt? • Build up walls and floors of existing shrimp ponds Suitable sediment for shrimp and meiofauna Source: Pickering et al. (2011), Della Patrona et al. (2011)
How should we adapt? • Select sites for seaweed farms near upwelling areas and at low risk from increased freshwater runoff • Use temperature- and salinity-tolerant strains to avoid “ice-ice” and EFA Photo: Gideon Tiroba Photo: George Steinmetz
Pearl • It will be impossible to project production changes for pearl until more is known about the likely effects of seawater acidification
Shrimp • Subject to adaptive strategies being successful and cost-effective, New Caledonia can double its present size (i.e. to 4000 tonnes per annum and 1000 livelihoods) • Fiji could develop to 1000 T in the medium term • PNG could develop to 2000 T • But profit margins will be less
Kappaphycus seaweed • Medium-term production targets of around 1000 tonnes per year (engaging several hundred households) in each of Fiji, Solomon Islands Kiribati and Fiji should still be achievable • But not in the same places, by the same methods, or with the same varieties in current use.
Other commodities • Marine finfish, mud crab, corals, giant clam, trochus, live rock and sea cucumber are fledgling industries, so projected change from current production levels will be small, however ... • Loss of development potential represents a massive opportunity cost for the region.
Conclusion • Mariculture has much scope for development over the next 40 years and beyond • But production efficiency is likely to be affected by increased CO2 emissions
We need more research on the effects of climate change, and on ways for aquaculture to be adapted to the adverse effects Thank you