MTH Chowdhury, ZP Sukhan 1 , MA Hannan
Department of Biotechnology, Pukyong National University, South Korea
1 Laboratory 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.

Freshwater
Fisheries
Directly affect
Marine Fisheries
Fish Production
Temperature
Rainfall
Hydrology

Source: Macfadyen, G., and Allison, E. (2009). P 38.

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
4.48 %
AGRICULTURE
2 nd ; 4.83%
PROTEIN SUPPLY
12 M+
58.0 %
20.87 %

• 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

Poikilothermic animal
Growth, reproduction & activity are directly influenced by the change of temperature
INVERSELY RELATED TO
&

&
EFFECT ON FRESHWATER FISHES IN BANGLADESH
DISSOLVED has harmful effect in pond fish culture
SURFACE &
VOLUME OF
POND WATER

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
Year Temperature change ( O C) Precipitation change (%)
Dec-Jan-Feb
(Dry Season)
Jun-Jul-Agu
(Wet Season)
Dec-Jan-Feb
(Dry Season)
Jun-July-Aug
(Wet Season)
Baseline
Average
-
2278 mm
33.7
Mm
1343.7 mm
2030 1.0
1.1
0.8
+3.8
-1.2
+4.7
2050 1.4
1.6
1.1
+5.6
-1.7
+6.8
2100 2.4
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
1
KILL
2

EFFECT ON OPEN WATER FISHERIES RESOURCES
+
Runoff with
Higher Nutrient
Floodplain &
Productivity

Ranching
In Monson
EFFECT ON OPEN WATER FISHERIES RESOURCES brings Revolution in Fish Production
Runoff Flood Destroy aquaculture
Infrastructure reduced the closed water aquaculture production

EFFECT ON OPEN WATER FISHERIES RESOURCES
Aquatic
Macrophyte
2-3 O C of temperature cause 300-500% of macrophyte production
1
2
3
Decrease productivity
Reduce fish habitat
Reduce dissolved Oxygen
Create anoxic condition
Bangladesh might face this problem

The main impacts of climate change on coastal area in
Bangladesh are
1 Sea Level rise
2
3
Reduction of freshwater availability by salinity intrusion
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

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)

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

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

• 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 CO
2 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 CO
2 also reduces the pH of animal tissue and it may affect the marine fish physiology.

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.