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CLIMATE CHANGE AND ITS IMPACT ON
FISHERIES RESOURCES IN BANGLADESH
MTH Chowdhury, ZP Sukhan1, MA Hannan
Department of Biotechnology, Pukyong National University, South Korea
1Laboratory of Marine Biology, Kyushu University, Japan
Presenter
Muhammad Tanvir Hossain Chowdhury
PhD Student, Department of Biotechnology
Pukyong National University, Busan, Korea
International Conference on Environmental Aspects of Bangladesh (ICEAB)
Sept. 4, 2010. Japan.
INTRODUCTION
Directly affect
Freshwater
Fisheries
Marine Fisheries
Fish Production
Temperature
Rainfall
Hydrology
On the basis of vulnerability
Source: Macfadyen, G., and Allison, E. (2009). P 38.
On the basis of adaptive capacity
Source: Macfadyen, G., and Allison, E. (2009). P 38.
INTRODUCTION
most vulnerable countries in Asia
depending on the vulnerability of national
economy to the impacts of climate change on
fisheries
Combined
Effect of
* Predicted warming
* Relative importance of fisheries
to national economics and diet
* Limited societal capacity to
potential impacts and opportunities
has lowest adaptive capacity to
climate change in fisheries
• Climate change directly affect fishery
production
• Fish reproduction, growth and migration
patterns are all affected by temperature,
rainfall and hydrology
• Climate change is likely to adversely affect
both the fresh water and marine fisheries in
Bangladesh.
INTRODUCTION
Contribution of Fisheries Sector in Bangladesh
Foreign
Exchange
GDP
2nd; 4.83%
4.48 %
12 M+
AGRICULTURE
PROTEIN SUPPLY
20.87 %
58.0 %
CAUSES OF CLIMATE CHANGE
• Green house gases like carbon dioxide, methane
and nitrous oxide have increased).
• The global increase of carbon dioxide is due to the
use of land and fossil fuel,
• Increase of methane and nitrous oxide are due to
agriculture
• Rising concentration of the green house gases in
the atmosphere are causing global climate change
EFFECT ON FRESHWATER FISHES IN BANGLADESH
Poikilothermic animal
&
SALINITY
INVERSELY RELATED TO
TEMPERATURE
Solubility of
Growth, reproduction & activity are directly
influenced by the change of temperature
DISSOLVED
&
has harmful effect in
pond fish culture
ACTIVITY
EVAPOTRANS
-PIRATION
TEMPERATURE
TEMPERATURE
EFFECT ON FRESHWATER FISHES IN BANGLADESH
SURFACE &
VOLUME OF
POND WATER
EFFECT ON OPEN WATER FISHERIES RESOURCES
Contribute nearly 1 million
metric ton of fish
Inundated during the flood stages
Isolated from the main channel
during the dry season
Regular flooding ensures the
reproductive success of the fish
EFFECT ON OPEN WATER FISHERIES RESOURCES
GCM estimates of temperature and precipitation changes in Bangladesh
Temperature change (OC)
Year
Jun-Jul-Agu
(Wet Season)
-
-
-
2030
1.0
1.1
2050
1.4
2100
2.4
Baseline
Average
Annual
Annual
Dec-Jan-Feb
(Dry Season)
Precipitation change (%)
Dec-Jan-Feb
(Dry Season)
Jun-July-Aug
(Wet Season)
2278
mm
33.7
Mm
1343.7
mm
0.8
+3.8
-1.2
+4.7
1.6
1.1
+5.6
-1.7
+6.8
2.7
1.9
+9.7
-3.0
+11.8
This model was run by the IPCC (Inter-government Panel on Climate Change) B2 scenario
EFFECT ON OPEN WATER FISHERIES RESOURCES
EVAPOTRANSPIRATION
VOLUME & FAVORABLE
FISH HABITATS
KILL
The Survival of
Next Year’s Brood
For Reproduction
CHALLENGE
2
1
EFFECT ON OPEN WATER FISHERIES RESOURCES
Runoff with
+Higher
Nutrient
Floodplain &
Productivity
Extend the Feeding
Ground of Fish
EFFECT ON OPEN WATER FISHERIES RESOURCES
Ranching
In Monson
Runoff
brings Revolution in Fish Production
Flood
Destroy aquaculture
Infrastructure
reduced the closed water
aquaculture production
TEMPERATURE
EFFECT ON OPEN WATER FISHERIES RESOURCES
Aquatic
Macrophyte
2-3OC of temperature
cause 300-500% of
macrophyte production
1 Decrease productivity
2 Reduce fish habitat
3 Reduce dissolved Oxygen
Create anoxic
condition
Bangladesh might face this problem
EFFECT ON COASTAL AREA
The main impacts of climate change on coastal area in
Bangladesh are
1
Sea Level rise
2
Reduction of freshwater availability
by salinity intrusion
3
Increasing cyclone frequency
4
Decrease Brackish water fish production
EFFECT ON COASTAL AREA
1
Water salinity varies from 0-20 ppt
2
Water salinity and its distribution are
increasing with the increase of sea level
rise
3
Soil salinity in South Western part of Bangladesh
is also increasing
Area (hectare)
EFFECT ON COASTAL AREA
Increasing rate of soil salinity area of southern part of Bangladesh
EFFECT ON COASTAL AREA
Cyclone
Sidr (15 Nov., 2007) and
Aila (27 May, 2009)
hit South and South West part of Bangladesh and
destroy the coastal embankment infrastructure and
increase the salinity
This salinity intrusion including sea level rising
creates harmful effect on existing fish species.
Water salinity exceeds the expected salinity level
that especially required for fresh water fish
production
EFFECT ON COASTAL AREA
SALINITY INTRUSION
Positive Effect
Create opportunities for
catching and cultivating
brackish and marine
species
Negative Effect
threatened to fresh
water fisheries
Loss of fish biodiversity
Potential species
Penaeus vannamei (Western White Shrimp)
Penaeus monodon (Tiger Shrimp)
Chanos chanos (Milk Fish)
Mugil cephalus (Mullet)
Tilapia nilotica (Tilapia)
EFFECT ON SUNDARBAN FISHERIES
World’s Largest single chunk of continuous mangrove forest
Fish species inhibit : 175
Supports offshore & deep sea fisheries by playing as
nursery ground for many deep sea fishes and shrimps
Act as protecting wall against the
devastating cyclones and tidal
surges by deflecting and reducing
energy
EFFECT ON SUNDARBAN FISHERIES
Highly vulnerable to sea level rise and will be
disappear by 1 meter rise of the sea level
Sea level rise may destroy the mangrove forest as
well as destroy the marine fish nursery ground
Effect on marine fisheries
• Average tropical sea surface temperature is predicted
to increase by 50-80%.
• Increased temperature may affect the distribution
pattern of some fish species
• Some of them may be migrate to the higher latitude
for cooler place.
• Atmospheric CO2 level will be high and this will cause
the average ocean pH to drop by 0.4-0.5
• Fish embryos and larvae are more sensitive to pH
change than juvenile and adults.
• Eggs of the pelagic fishes might be more susceptible
to pH change.
• Increased level of dissolved CO2 also reduces the pH
of animal tissue and it may affect the marine fish
physiology.
CONCLUSION
Bangladesh economy is vulnerable to climate change
impact, which could affect our food security and level of
poverty by elevating stress on fisheries production
But the detailed effects on climate change
affecting the fisheries sector is yet uncertain.
It might bring economic hardship or might
increase the opportunity to higher fish production
through adaptive measure and increase the
economic growth.