4. Climate
change
stressors
Short-term
fluctuations
Seasonal patterns
Precipitation
Severe storms
Temperature
Winds
Long term
change
Sea Level Rise
Ocean currents
Warming
Acidification
Freshwater
availability
Impacts on
aquatic
environments
Impacts on
aquatic
ecosystems
Impacts on
aquatic species
Impacts on
aquaculture
Impacts on
fisheries
Roles of aquatic resources for adaptation and mitigation
Conclusions, recommendations and priority actions
Regional
implications
Africa
Latin America/
Caribbean
North America
Asia
Europe
Oceania
Report structure
10. Increasing acidification of the ocean
(IPCC Fourth Assessment Report)
• Dissolved CO2 forms a weak acid
• pH decreases as dissolved CO2
increases
• Direct observations of pH over last
two decades show pH decreases of
about 0.02 units per decade
• Projections based on SRES
scenarios give reductions in
average global surface pH of 0.14
to 0.35 units over the 21st century
• Bad news for marine organisms
which use aragonite and calcite to
build shells
European Station for
Time Series in the
Ocean (29˚N, 15˚W)
Hawaii Ocean Time
Series (23˚N, 158˚W)
Bermuda Atlantic
Time Series Study
(32˚N, 64˚W)
12. Seasonal pattern change
• Rainy season starting early / late
• Hot season starting early / late
• Rains during dry season
• Dry during rainy season
14. Key aquatic habitats
Fisheries and aquaculture are dependent on
a number of key aquatic habitats that are
affected by Climate Change
• Coral reefs
• Sea grass beds
• Mangroves
• Agricultural wetlands
• Flooded forests
15. Coral reefs
– Provide food and shelter for an estimated
25% of known marine fish species
– Indicator (Bleaching) of ecological impacts of
short term Climate Change
• Susceptible to
– Ocean acidification
– Increasing seawater temperature
– Precipitation patterns – river plumes
– Strong waves and currents
– Sea level rise
– Extreme weather events
17. Coral reefs
• Ocean acidification
– Affect coral growth and recruitment
• Precipitation
– Low tolerance of salinity change
– Prone to increasing water run off and
sediment plumes
• Temperature and ENSO
– Increase in temperature by 1-3 deg C can
trigger coral bleaching
– Recovery is possible to various extents, with
time
18. Sea grasses
– Important nursery grounds for juvenile fish
– Important feeding grounds
– Some species are very slow growing; e.g.,
Posidonia
• Susceptible to
• Temperature
– Increasing seawater temperature; e.g.,
Mediterranean
– Large temperature fluctuations
– Extreme heat waves
19. Mangroves
– Important spawning and nursery grounds
– Provide coastal protection
• Susceptible to
– Sea level rise
• Increasing salinity
• Increased flooding
• Move range inland if possible (needs time)
– Extreme weather events
• Tropical storms and typhoons – damage
• Remove peat deposits
• Bring sulphide-rich sediments to surface
20. Anticipated impacts and negative outcomes for fisheries
Adapted from Allison (2009)
Ocean current change
ENSO
Sea level rise
Rainfall
River flow
Lake levels
Temperature changes
Storm severity
Storm frequency
Acidification
Species composition,
productivity, species
distribution, diseases, coral
bleaching, calcifiers
Catch effort, safety at sea,
fishing areas
Increased operational
costs, reduction in
livelihoods, loss and
damage, displacement,
food security
Climate change
Negative
Outcomes
Degraded
production ecology
Impoverished
communities
and livelihoods
Higher risk
fishing operations
Wider societal
and economical
burdens
Adaptation costs, market
impacts, water resource
allocation
Impacts
21. Fisheries – inland fisheries
– Fragmented populations (especially freshwater)
– High genetic diversity
• Susceptible to
– Temperature fluctuations – changes in lake water
stratification
– Precipitation – river flows
– Low dissolved oxygen
– Lake and reservoir turnover
– Water quality changes
– Changes in connectivity of waters
22. Fisheries – Inland fisheries
Impacts
• Temperature
– Water stratification – species composition
– Breeding timing and cues
– Evapotranspiration – water levels
– Poleward/upstream range changes or extinctions
• Precipitation
– Water flows – droughts, water levels, habitat loss,
– salt water intrusion – range loss – fish yields lower
and unpredictable
• Glacial melt – dry season river flows
– Higher nutrient / pollutant levels – fish yields
23. Fisheries – Inland fisheries
Impacts
• Sea level rise
– Saltwater intrusion – estuaries, deltas, rivers
– Reduce FW habitats especially deltas
• Lake water levels
– range loss
– reduced reproduction
– fish yields lower and unpredictable
• Wind pattern changes
– change in water mixing
– change in yields (natural productivity and fisheries)
•Great regional variation among river basins
25. Fisheries – Coastal fisheries
• Vulnerable ecosystems
– Sea grass beds
– Wetlands
– Estuaries
– Coral reefs
– Mangroves
• Susceptible to
– Seawater temperature change
– Freshwater run off and nutrient plumes
– Coastal currents change
– Extreme events/storms
– Impacts on coastal ecosystems
26. Fisheries – Coastal fisheries
Impacts
• Temperature change and fluctuation
– Spawning aggregations, initiation of spawning
– Early pelagic life stage - survival
– Change in natural range polewards
• Coastal current change
– Early pelagic life stage – range and survival
• Sensitive ecosystems
– Temperature/pH – coral bleaching
– Reduced reef fish yields, reduced abundance of small
fish
27. Fisheries – Pelagic fisheries
• Susceptible to
– Temperature – increasing
– Rainfall/water discharge – sediment plumes
– Changes in ENSO fluctuations affect industrial
fisheries
Impacts
• Temperature – increasing
– Changes in range polewards
28. Fisheries – Pelagic fisheries
Impacts
• Rainfall/water discharge – sediment
plumes
– Primary productivity and yield
• Changes in ENSO fluctuations
– Peruvian anchoveta (for fishmeal and fish oil)
and tropical tunas
– Increased year to year catch variability
29. Fisheries – Marine demersal
– Mainly on continental shelves
• Susceptible to
– Temperature increase
• Impacts
– Natural range change poleward
– Change in zooplankton prey affecting yield;
e.g., copepods on cod recruitment and
abundance
30. Fisheries – Highly migratory
– Eels
– Salmon
– Sturgeons
– Tuna
• Susceptible to
– Seasonal pattern change
– Precipitation - river flow change;
droughts/floods
– Changes in currents
– Change in North Atlantic Oscillation (NAO)
31. Fisheries – Highly migratory
Impacts
• Seasonal pattern change
– Environmental variables used as migratory cues – migrate
earlier or later
• Temperature increase, surface temperature anomalies,
NAO
– Affect range of the species
– Affect the migration route and extent
• Precipitation - river flow change
– Restricts upstream migration (e.g., salmon)
• Current direction and strength
– Effects distribution and range (e.g., eels) – strength and position
of Gulf Stream
32. Fisheries – Culture-based fisheries
• Freshwater
– Restocking lakes and reservoirs (e.g., carps, tilapias,
coregonids)
• Marine
– Stock enhancement/ranching (e.g., scallops)
• Conservation (e.g., sturgeons)
• Introductions and alien species (e.g., carps,
tilapias, Nile perch
34. Top fed aquaculture & livestock
producers – 2008
APR 10.59% since 1980 APR 2.59% since 1980
(FAO – FISHSTAT/FAOSTAT, 2010)
Fisheries and aquaculture supply 114 million tonnes of fish for food (SOFIA 2010)
35.
36. Aquaculture – seed supply
• Wild seed based aquaculture
• Fish – eels, tunas, milkfish, etc.
• Molluscs – oysters, mussels, clams
• Seaweeds
– Susceptible to
• pH, temperature increase and fluctuations, water
current change
– Impacts
• Recruitment, larval distribution, larval survival
• Hatcheries
– Impacts
• Water quality; breeding cycles; egg development
37. Aquaculture – FW Ponds
• Freshwater ponds (shallow)
– Fish ( e.g., carps, catfishes, tilapias, charrs,
trout)
– Crustaceans (freshwater prawns)
• Susceptible to
– Droughts, floods, changes in precipitation,
saltwater intrusions, temperature increases,
temperature fluctuations
• Impacts
– Natural productivity, fish stress, growth rate,
survival
38. Aquaculture – Brackish water and marine ponds
• Shallow ponds
– Fish milkfish, mullets
– Crustaceans – prawns
• Susceptible to
– Temperature, intense rainfall, storm surge,
floods
• Impacts
– Natural productivity, fish stress, growth rate,
survival
39. Aquaculture - tanks and raceways
• Gravity flow
– Salmonids (e.g., trout)
• Pumped
– eels, catfishes, tilapias, ornamental species
• Susceptible to
– Water supply change
– Changes in ambient water quality (pH, temperature,
water flow, etc.)
• Impacts
– Fish stress, disease, productivity
Recirculation can reduce vulnerability
40. Aquaculture - cages and pens
• Sheltered
– FW (lakes/reservoirs/rivers) – carps, tilapias,
– BW/M (bays/lagoons) – milkfish, groupers, snappers, seabass
• Exposed/offshore
– M – salmon, seabass, seabream
• Susceptible to
– Sheltered – oxygen levels, overturn
– Exposed - storms/squalls and typhoons/hurricanes (increasing
intensity and frequency)
• Impacts
– FW – oxygen levels, productivity
– M – facility damage, interruption of activity, fish loss/escape
41. Aquaculture - rafts and ropes
• Rafts
– Oysters, mussels, scallops
• Ropes
– Mussels, seaweeds
• Susceptible to
– pH decrease, water quality change, circulation
change, storms/squalls and typhoons/hurricanes
(increasing frequency and intensity)
• Impacts
– Recruitment (range and survival), productivity,
structural damage
42. Aquaculture - tidal culture
• tidal flats/mud flats
– clams, oysters, mussels
• Susceptible to
– extreme temperature, temperature
fluctuations, pH change,
– sea level rise, storms, storm surges, (change
of substrate type)
• Impacts
– recruitment, culture range, production loss
43. Aquaculture - Integrated Farming and
Integrated Multi-Trophic Level
Aquaculture (IMTA)
• Integrated Farming
– Fish/livestock – ducks, chickens
– Fish/crop – rice/shrimp
– Fish/nutrient waste – feedlot systems
• IMTA
– Fish – fed nutrient input
– Mollusc – extractive particulate nutrients
– Seaweed – extractive dissolved nutrients
Spreading risk among enterprises and products
44. Preliminary Analysis – Aqua Maps
• 342 marine fishes with verified maps
• Global suitable habitat in 1999 and 2050
• Only core habitat considered (P > 0.5)
Current
Species
richness
Source: Rainer Froese, IFM-GEOMAR, Kiel, Germany, EDIT Symposium
45. Preliminary Analysis – Aqua Maps
• 342 marine fishes with verified maps
• Global suitable habitat in 1999 and 2050
• Only core habitat considered (P > 0.5)
Predicted
Species
Richness
2050
Source: Rainer Froese, IFM-GEOMAR, Kiel, Germany, EDIT Symposium
46. Preliminary Analysis – Aqua Maps
• 342 marine fishes with verified maps
• Global suitable habitat in 1999 and 2050
• Only core habitat considered (P > 0.5)
Drop in
Species
Richness
Current-2050
Source: Rainer Froese, IFM-GEOMAR, Kiel, Germany, EDIT Symposium
47. More Losers than Winners
suitable habitats
0
30
60
90
120
150
-100 -80 -60 -40 -20 0 20 40 60 80 100
Changeinarea(%)
Count
Change in area of suitable habitat between 2000 and 2050 for 342 marine fishes.
Median loss of area is 6% (95% CL 3.8 – 7.4), significantly different from zero.
Source: Rainer Froese, IFM-GEOMAR, Kiel, Germany, EDIT Symposium
48. Deeper is Better
Change in area by preferred habitat of marine species. For 41 deep sea fishes, the median change of +2%
(95% CL -0.9 – +3.7. For 103 demersal fishes, median loss is 3% (95% CL -6.5 - -0.9). For 31 benthopelagic
fishes, the median loss of 3.3% (95% CL -12 – 3.8. For 55 pelagic fishes, the median loss is 13%
(95% CL -17 - -2.9). For 112 reef-associated fishes, the median loss is 10% (-17 - -6.5).
-100
-80
-60
-40
-20
0
20
40
60
1bathy 2dem 3bpel 4pel 5reef
Changeinarea(%)
Deep sea fish +2.0%
Demersal fish -3.0%
Benthopelagic -3.3%
Reef fish -10%
Pelagic fish -13%
49. Polar and Tropical Fishes Lose
Change in area by climate zone. For 43 deep sea species, the median change is not significantly different
from zero (median 1.8, 95% CL -2.5 – 3.7). Of five polar species, three lose 9 to 32% of suitable area.
For 50 temperate species, median change is +2.3% (95% CL -0.1 – 4.0). For 112 subtropical species, the
median loss is 7% (95% CL 3.8 – 13) and for 132 tropical species the median loss is 9% (95% CL 7 – 15).
-100
-80
-60
-40
-20
0
20
40
60
1deep 2polar 3temp 4sub 5tropical
Changeinarea(%)
Deep sea fish 0%
Polar fish -9 to -32%
Temperate +2.3%
Sub-tropical -7.0%
Tropical fish -9.0%
50. Change in fisheries catch
Projected changes in averaged maximum catch potential from 2005
to 2055 by the 20 Exclusive Economic Zone regions with the highest
catch in the 2000s
Source: Pew Sea around us project – Fisheries, Ecosystems and Biodiversity
51. Vulnerability - Fisheries
More vulnerable Less vulnerable
Inland Marine
Shallow water Deep water
Long pelagic stage Short pelagic stage
Complicated life cycle Simple life cycle
Long generation time Short generation time
Narrow tolerance range Wide tolerance range
Sessile species Mobile species
Less fecundity Great fecundity
52. Vulnerability - aquaculture
More vulnerable Less vulnerable
Freshwater Marine water
Shallow water Deep water
Wild fry/seed collection Hatchery production
Long culture cycle Short culture cycle
Narrow tolerance range Wide tolerance range
High trophic level species Low trophic level species
53. Probable outcomes of climate change on
aquatic genetic resources for major taxa
Taxa Warming Acidification Elevated N, P
Microalgae With increased
nutrients, algal
blooms are enhanced;
oxygen is
periodically depleted
Calcite formation is
reduced; e.g., in
coccolithophores
Eutrophication and
harmful algal blooms,
including red tides are
enhanced
Macroalgae;
freshwater
macrophytes
Enhanced biomasses,
with increased
nutrients; periodic
oxygen depletion due
to die-offs; thermal
stratification is
increased
Coralline algae are
reduced and more
susceptible to diseases and
grazing
Eutrophication and
biomasses increase
Crustaceans Gamete are less
viable in decapods
and barnacles;
disease problems
increase
Food sources are reduced;
larval development and
building skeletal
structures may be
compromised; recruitment
is lowered
Eutrophication and
harmful algal blooms
are increased, with
periodic oxygen
depletion; e.g., on
nursery grounds
54. Probable outcomes of climate change on
aquatic genetic resources for major taxa
Taxa Warming Acidification Elevated N, P
Molluscs Disease problems and
irradiation stress
increase
Shell formation is
compromised and
recruitment lowered
Water toxicity and
harmful algal blooms
increase
Other aquatic
invertebrates:
e.g., corals,
echinoderms
Corals are bleached
and suffer increased
viral attacks; sea
urchin gametes are less
viability and
fertilization is reduced
Calcareous skeletal
structures are
compromised
Water toxicity and
harmful algal blooms
increase; lower light
reduces photosynthesis
in coral symbionts
Finfish Distributions and
migrations are altered,
poleward shifts in
some species; water
column mixing and
available oxygen
decrease; some disease
problems increase
Distributions and
migrations are altered
in pH -sensitive species
Water toxicity and
harmful algal blooms
increase
55. Fostering Adaptation and Mitigation: Our ‘Take
Home Messages’
MUSTS TO DO
• Take good care of aquatic ecosystems
• Maintain diverse gene pools, supporting
conservation of genetic resources as a sector
• Address ALL of the anthropogenic stressors
that work against these goals; not only climate
change
MUSTS TO AVOID
• Unsustainable exploitation of natural resources
• Degradation and loss of habitats
• Sector-specific policies, institutions and
actions that produce conflicts and miss
opportunities for multi-sector partnerships and
synergy
59. Minimum temperature differences
2020
Increase by 0.75 ‘C in January and from
July to November
Increase of 1.2 ‘C in May and December
2050
Increase of 1 to 1.5 ‘C in January and from
July to November
Increase of 2 ‘C in May and December
64. Monthly temperature fluctuation
2020
Higher fluctuation in January (0.5 ‘C) and
February (1 ‘C)
Less fluctuation in May (0.5 ‘C)
2050
Higher fluctuation in January and October
(0.5 ‘C) and February (1 ‘C)
Less fluctuation in May (0.5 ‘C)
67. Differences
2020
Generally slightly higher (20 mm /month)
Higher rainfall in June (100 mm)
Lower rainfall in July (60 mm)
2050
Generally higher in the first half of the year (20
mm)
Generally lower in the second half of the year (20
mm)
Higher in May (40 mm) and July and August (90
mm)
