CLIMATE CHANGE AND ITS IMPACT ON FISHERIES

RESOURCES IN BANGLADESH

International Conference on Environmental Aspects of Bangladesh (ICEAB)

Sept. 4, 2010. Japan.

PresenterMuhammad Tanvir Hossain Chowdhury

PhD Student, Department of Biotechnology Pukyong National University, Busan, Korea

MTH Chowdhury, ZP Sukhan1, MA Hannan Department of Biotechnology, Pukyong National University, South Korea

1Laboratory of Marine Biology, Kyushu University, Japan

INTRODUCTION

TemperatureRainfall

Hydrology

Directly affect

Freshwater Fisheries

Marine Fisheries

Fish ProductionFish Production

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.

INTRODUCTIONmost vulnerable countries in Asia

depending on the vulnerability of national economy to the impacts of climate change on fisheries

VULNERABILITY

* Predicted warming

* Relative importance of fisheries to national economics and diet

* Limited societal capacity to potential impacts and opportunities

CombinedCombinedEffect ofEffect of

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

12 M+2nd; 4.83%

Foreign Exchange

4.48 %

GDP

Contribution of Fisheries Sector in Bangladesh

PROTEIN SUPPLY

58.0 %20.87 %

AGRICULTURE

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

Growth, reproduction & activity are directly influenced by the change of temperature

TE

MP

ER

AT

UR

E

SAL

INIT

Y

Sol

ubili

ty o

f

INVERSELY RELATED TO

&

TE

MPE

RA

TU

RE

DISSOLVED

has harmful effect in pond fish culture&

EFFECT ON FRESHWATER FISHES IN BANGLADESHTEM

PER

ATU

RE

ACTIVITYEV

APO

TR

AN

S-P

IRA

TIO

NSURFACE & 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

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

1C

HA

LLEN

GE

The Survival ofNext Year’s

BroodFor

Reproduction

2

EFFECT ON OPEN WATER FISHERIES RESOURCES

Runoff with

Higher Nutrient

Floodplain &

Productivity

+

Extend the Feeding Ground of

Fish

EFFECT ON OPEN WATER FISHERIES RESOURCES

Runoff Flood Destroy aquaculture

Infrastructure

RanchingIn

Monson

brings Revolution in Fish Production

reduced the closed water aquaculture

production

EFFECT ON OPEN WATER FISHERIES RESOURCES

Decrease productivity

TEM

PER

ATU

RE

Aquatic Macrophyt

e

Reduce fish habitat

Reduce dissolved Oxygen

Create anoxic

condition

Fish KIL

L

Bangladesh might face this problem

2-3OC of temperature cause 300-500% of macrophyte production

1

2

3

EFFECT ON COASTAL AREA

Sea Level rise

The main impacts of climate change on coastal area in Bangladesh are

1

Reduction of freshwater availability by salinity intrusion

2

Increasing cyclone frequency3

Decrease Brackish water fish production4

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

Area

(he

ctar

e)

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

Negative EffectPositive Effect

threatened to fresh water fisheriesLoss of fish biodiversity

Create opportunities for catching and cultivating brackish and marine species

Potential speciesPenaeus vannamei (Western White Shrimp)Penaeus monodon (Tiger Shrimp) Chanos chanos (Milk Fish) Mugil cephalus (Mullet) Tilapia nilotica (Tilapia)

EFFECT ON SUNDARBAN EFFECT ON SUNDARBAN FISHERIESFISHERIES

World’s Largest single chunk of continuous mangrove forestFish 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 EFFECT ON SUNDARBAN FISHERIESFISHERIES

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.

CONCLUSIONCONCLUSION

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.