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Climate Change and Aquaculture
Graham Mair (FAO)Lionel Dabbadie (FAO/CIRAD)
Eradicate hunger, foodInsecurity and malnutrition
Eliminate rural poverty through socio-economic development
Manage and sustainably usenatural resources
FAO’s mandate:Lead global efforts to eliminate poverty and hunger
Aquaculture is critical to future seafood supply
• Aquaculture will supply future growth in seafood production for foreseeable future
• Aquaculture production is primarily in the developing world
Climate change and aquaculture
2. Impact of climate change on aquaculture
– Drivers
– Vulnerability
– Adaptation
1. Contributions of aquaculture to climate change?
https://grimstad.uia.no/puls/climatechange/nng01/02nng01.htm
1 0 0 1 1 1 0 1 2 1 1 1 3 6 83 5 4 7
192222
4436
6157
61
99105
37 7 10
6 9 8 7 10
0
20
40
60
80
100
120
Number of published scientific papers per year dealing with aquaculture and climate change in Scopus and FAO databases, as a proxy of interest in the issue
Number of publications in Scopus
Number of FAO publications
Contributions of Aquaculture to climate change
• Greenhouse gases (CO2, methane, nitrous oxide, fluorinated gases)
• Rising emissions– Burning fossil fuels– Deforestation– Livestock farming– Fertilizers– Fluorinated gases
• Land use
• Transport
• There are other environmental costs of agri/aquaculture
Planet has already warmed 0.85°C, target to limit <2°C
CSS
R 4
thN
ati
on
al C
lima
te A
sses
smen
t C
ha
pte
r 2
EAT-Lancet Report
https://eatforum.org/eat-lancet-commission/
Environmental effects per serving of food produced
Environmental effects of food production
https://eatforum.org/eat-lancet-commission/
Aquaculture vs Wild catch
0 1 2 3 4 5 6 7
Tilapia in cages in lakesSalmon in Norway
Salmon in ChileSalmon in UK
Vietnamese Pangasius pondsTrout flow through
Trout RAS FranceSeabass cages
Turbot RASMussel Rafts
Cod in NorwayCod gillnet (Sweden)
Cod trawling (Sweden)Cod in Denmark
Plaice in DenmarkCod Flyshoot (NL)Plaice twinrig (NL)
GWP (kg CO2 eq/kg of fillet)
Wild
cat
chA
qu
acu
ltu
re
Rasenberg et al, IMARES, 2013
Aquaculture systems
Relative GHG emissions decrease with increasing intensity of production
N2O
MethaneCO2
Yuan et al, Nature Climate Change 9, 2019
Key Message
Although aquaculture is not benign with regard to contributions to greenhouse gases its impacts on climate change are not likely to be significant
relative to other impacts on the environment and the relative impacts of other forms of
agriculture.
Direct impacts of climate change onaquaculture
Direct drivers of
change
Warming
Ocean acidification
Hypoxia
Distributional shifts
Sea level rise
Currents, circulation and wind
Extreme events
Disease and algal
blooms
Mix of +ve and –ve impacts Primarily -ve impacts
Warming
Italy (Verona):• Temps rising @ .35C per decade• +2.5C by 2050• 40+ days pa over 35C by 2100
EEA Climate report 2012
BBC, 2018
The Guardian, 2019
Warming – Biological effectsPositive impacts
+ Increased growth rate & production efficiency
+ Shorter production cycles, improved FCR = profit↑
Negative impacts- Shift away from culture of species
with narrow thermal range
- Increased sensitivity to other drivers (e.g. pathogens)
- Harmful algal blooms
Neutral/indeterminate impacts
• Increased plankton respiration/ proliferation
• Mollusc spatfall changes
• Changes in reproduction & sex ratios
• Increased/decreased diseasetransmissionPerson-Le Ruyet et al, 2004. Aquaculture
Effect and adaptation
Effect
• New areas become favourable for aquaculture, others become unfavourable
• Will need increased monitoring of key environmental variables
• The most resilient and temperature labile species may develop on scale
Adaptation
• Shift to species/strains with higher thermal tolerance (genetic selection for adaptation)
• Shifting farms to higher latitudes or cooler deeper offshore and inland areas
• Adjusting farm calendars
• Climate smart farms (e.g. deeper ponds)
• Long term spatial planning
Extreme Events are already happening in > frequency
** *
*
**
*
**
*
* Potentially most impactful on aquaculture
www.carbonbrief.org
Extreme events – Impact & Adaptation
Negative impacts- Impacts on water quality
- Mass mortalities or losses
- Increased sensitivity to other drivers
- Supply of inputs or market access disrupted
- Loss of infrastructure
- ↑hazards to workers
- Loss of livelihoods
- Eutrophication, pollution, erosion/silting, FW run off, escapes
Adaptation measures
• Shift towards more tolerant species
• Ensure safety at work (followguidelines)
• Shift to shorter production cycles ↓ reduce risk
• Shift to indoor RAS systems
• Invest in water efficient technology
• Invest on more robust infrastructure
• Relocate farms away exposed sites (↑ spatial planning)
• Certification systems/standards
• Investment in mitigation measures
Sea level rise
• The sea level has been rising for some time
• Rates of rise likely to increase
• Mean sea levels predicted to rise 0.4-0.7m by 2100
• Spatial distribution of sea level rise not even
EEA Climate report 2012, EEA.Europa.eu (2017)
Sea level rise
Negative impacts- Saline intrusion may ↓growth,
↑increase mortality, ↑sensitivity
- Displacement of people
- Loss of physical protection, ↑exposure
- Loss of intertidal areas
- Coastal erosion
- Flooding of coastal rivers
- Shift of activities upstream
+ New opportunities for coastal aquaculture
Adaptation
• Shift towards natural or selected saline tolerant freshwater species/strains
• Shift towards euryhalineestuarine or marine species
• Mainstream ecosystem approach to aquaculture
• Support local governance engaging aquaculture stakeholders
• Invest in protection infrastructure (e.g. dams/dykes)
• Mainstream spatial planning
In-direct impacts of climate change onaquaculture
In-Direct drivers of
change
Uncertainty
Water shortage
Impacts on fisheries
Impacts on agriculture
National adaptation
plans
EEA
Clim
ate
rep
ort
201
2
Effects of climate change are and will be real and should be factored into aquaculture planning & development
• Aquaculture will not be a major factor impacting on climate change
• Significant effects will arise from interrelated impacts of: warming, ocean acidification, hypoxia, sea level rise, extreme events, distributional shift, disease and algal blooms
• Impacts will be on: productivity/profitability, species choice/dominance, sensitivity, HABs, disease, reproduction, relocation, losses
• Adaptations will need to include: Species shifts/selective breeding for adaptation, modifying and changing systems and management, spatial planning, modifying infrastructure and certification
Seaweed farming, Kiribati
Tilapia ponds, Egypt
Thank you!
[email protected]@fao.org
Direct and Indirect impacts of climate change will have +ve and –ve impacts on aquaculture
over different time and spatial scales