Global Implications of ENSO Events on Inland Fisheries
Transcript of Global Implications of ENSO Events on Inland Fisheries
Global Implications of ENSO Events on Inland Fisheries
Ian G. Cowx
INSERT PHOTOS
HERE
INSERT PHOTOS
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IFM, York, 21 May 2109
UNIVERSITY OF
Hull International Fisheries Institute
HIFI
Outline
• Where are we with research on extreme climate events.
• Impacts of extreme events on inland fisheries– Case studies: UK, African
Great Lakes, Mekong • Adaptation strategies and
increasing resilience
Winter
Summer
Current emphasis on climate research
Temperature and precipitation to 2050 (IPCC 2007)
IPCC predictions for inland areas are increased temperatures and regional variation in precipitation
Current emphasis on climate research
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Marine Inland
Expanding research focussing on marine environment and changes in distribution and phenology of species
Are we missing the impacts of extreme events – especially those driven by natural processes, e.g. ENSO?
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Marine Inland
UK floods and droughts
River Dibb, UK – April 18
River Dibb, UK – July 18
UK – July 17
UK – July 18
River Ouse, Yorkshire UK – July 07
2015 Winter floods – River Washburn
0+ brown trout
1+ brown trout
Similar response to trout populations across north of England – washout of spawning redds
African Great Lakes – fisheries yield
Prediction: Fisheries yield (kg/ha) dependent on seasonal relative lake level (Source Kolding et al. 2012)
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Variation in water level, Lake Malawi
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Lake level variability and el Niño
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Nile perch Dagaa Tilapias Haplochromines Others
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Lake
leve
l in
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(a.m
.s.l)
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Water level variation in Lake VictoriaVictoria
Lake Victoria - la Niña periodVictoria – Mara wetland
Fisheries of the lower Mekong Basin
ðEstimated 2.5 million t/yr
ð200+ species; 30+ of high commercial importance
ð > 40% of total fish catch in LMB (about 1.3 million tonnes worth US$6 billion) dependent on migratory fish
ð Fish production dependent on fish migration (all seasons of year) and extent of flooding
Drivers of fish productionWater level and flooding• Water level and extent of
flooding key drivers of fish production
• Shifts in fisheries productivity due to changes in hydrological patterns
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m)
meanannual
Annual Delta fishery
y = 47575x - 15010R² = 0.5366
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Catch rate
Water Level
Daily catch driven by water level in delta
Climate changePredicted effects of climate change in Lower Mekong Basin
Temperature Precipitation
Predicted alteration of flood cycleo Potential greater rainfall
in monsoon season in Viet Nam Highlands altering flooding magnitude, duration and extent in LMB
o More extreme flooding cycle.
o 3-10% increase in wet season flows
o 2-6% reduction in dry season flows
Predicted change in fish yield (t)
Mekong delta + 65,000Cambodian floodplain
+ 44,300
Tonle Sap + 30,200Total change + 139,500
Climate change – fish productionPredicted shift in daily discharge at Prek Kdam---- baseline---- Climate change scenario
= +10% increase in fish production
Lower Mekong Basin 2015 El NiñoAnnual water level in Tonle Sap, Cambodia –red indicates severe el Niño years
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Floo
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igh
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Biomass (Tonnes) Flood index
Severe reduction in flood peak and durationTonle Sap dai fishery closed early in November (2015) rather than February/March
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Tonle Sap 2015 El Niño
Exposure Sensitivity
Potential ecological impact
Recovery potential
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Resource dependency
Potential social impact
Adaptive capacity
Social- Ecological Vulnerability
Ecological Vulnerability
Feedbacks
Ecological
Socio-economic
Adaptation strategies
Adaptation: A process that aims to generate resilience to external stressors (related to resource dependence) and capacity to use potential opportunities in a sustainable and ethical manner
UK adaptation to floods and droughts
FloodsDredging: improved discharge capacity of riversNatural flood risk management: tree planting, reconnecting floodplains and buffer zones
DroughtsFlow Regulation: reduced compensation flows and regulate abstractionHabitat restoration – narrowing channels
Based on household surveys
• Shift in livelihoods of fishing communities towards employment such as construction [but not agriculture]
• Shift is diets: Fish and OAAs contribute about 70% of animal protein intake but drops to 54%
• Fish farming as non-equitable solution• Diplomatic engagement with China to
release water from upstream dams
Adaptation strategies - Mekong