Download Economic implications of projected changes to tuna

Projected changes
to freshwater aquaculture
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
• 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
1. Current and projected freshwater
aquaculture production
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.
• 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)
Tilapia/carp for Food security, Livelihoods
Cage-culture
Highlands
Lake restocking to replace
mossambicus with niloticus
Carp/tilapia
PNG
10-15,000 fish farms
Trout/tilapia
Highlands
Tilapia for livelihoods
Semi-intensive
culture in
earthen ponds
Aquaponics
Red Tilapia – Cage Culture
Intensive
Recirculating
Intensive flow-through
Lined ponds
Milkfish for food security
Brackish ponds
Freshwater ponds
Livelihoods
Cage culture for food, tuna-bait
Freshwater prawn Macrobrachium
Hatcherybased
culture
Macrobrachium rosenbergii
Capture-based culture
Macrobrachium lar
Integrated taro/prawn pond culture
Monoculture
SME approaches to food security
• Small household level aquaculture for
subsistence consumption is only viable with ongoing 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
Tilapia
• It is very difficult to
estimate tilapia
production in PICTs
• There are many smallscale farmers in very
remote places
• There are repeated
small harvests from
each pond, without
weighing
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
Livelihoods
Tilapia
Tilapia
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
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
2. Vulnerability of freshwater
aquaculture
Projected changes
Source: Lough et al. (2011), Ganachaud et al. (2011)
Temperature
2035
2050*
Spatial variation
in temperature
increase
2035
* Based on B1 2100
2100
Source: Lough et al. (2011)
Rainfall
Spatial variation in rainfall (winter)
2035
2100
Source: Lough et al. (2011)
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)
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.
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
Tilapia, freshwater prawn
• Water column stratification from higher temperatures creates a deoxygenated 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
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
3. Key responses and adaptations
How should we respond?
• Build fish ponds to avoid more severe floods
Photo: Avinash Singh
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
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]
4. Outlook for freshwater aquaculture
Outlook
• Aspirations for significant future
production (1000 - 2000 T per highisland PICT) and livelihoods
(between 10,000 to 20,000 persons
part-time) from inland aquaculture
are still likely to be realised.
Conclusion
• Freshwater pond aquaculture is likely to be
favoured by climate change
Source: Pickering et al. (2011)
Thank you