CLIMATE CHANGE AND ITS IMPACT ON FISHERIES RESOURCES IN BANGLADESH

1. 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.

2. INTRODUCTION Freshwater Fisheries Marine Fisheries Directly affect Fish Production Temperature Rainfall Hydrology

3. On the basis of vulnerability Source: Macfadyen, G., and Allison, E. (2009). P 38.

4. On the basis of adaptive capacity Source: Macfadyen, G., and Allison, E. (2009). P 38.

5. INTRODUCTION has lowest adaptive capacity to climate change in fisheries most vulnerable countries in Asia depending on the vulnerability of national economy to the impacts of climate change on fisheries * Predicted warming Combined Effect of VULNERABILITY * Relative importance of fisheries to national economics and diet * Limited societal capacity to potential impacts and opportunities

6. 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.

7. INTRODUCTION Contribution of Fisheries Sector in Bangladesh Foreign Exchange GDP 4.48 % 2nd; 4.83% 12 M+ PROTEIN SUPPLY AGRICULTURE 58.0 % 20.87 %

8. 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

9. EFFECT ON FRESHWATER FISHES IN BANGLADESH Poikilothermic animal Growth, reproduction & activity are directly influenced by the change of temperature TEMPERATURE INVERSELY RELATED TO Solubility of & SALINITY

10. EFFECT ON FRESHWATER FISHES IN BANGLADESH has harmful effect in pond fish culture & TEMPERATURE TEMPERATURE ACTIVITY DISSOLVED SURFACE & VOLUME OF POND WATER EVAPOTRANS -PIRATION

11. 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

12. 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

13. EFFECT ON OPEN WATER FISHERIES RESOURCES EVAPOTRANSPIRATION VOLUME & FAVORABLE FISH HABITATS The Survival of Next Year’s Brood For Reproduction 2 1 KILL CHALLENGE

14. EFFECT ON OPEN WATER FISHERIES RESOURCES + Runoff with Higher Nutrient Floodplain & Productivity Extend the Feeding Ground of Fish

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

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

17. EFFECT ON COASTAL AREA The main impacts of climate change on coastal area in Bangladesh are Sea Level rise 1 Reduction of freshwater availability by salinity intrusion 2 Increasing cyclone frequency 3 Decrease Brackish water fish production 4

19. EFFECT ON COASTAL AREA Water salinity varies from 0-20 ppt 1 Water salinity and its distribution are increasing with the increase of sea level rise 2 Soil salinity in South Western part of Bangladesh is also increasing 3

20. EFFECT ON COASTAL AREA Area (hectare) Increasing rate of soil salinity area of southern part of Bangladesh

21. EFFECT ON COASTAL AREA CycloneSidr(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

22. EFFECT ON COASTAL AREA SALINITY INTRUSION Negative Effect Positive Effect threatened to fresh water fisheries Loss of fish biodiversity Create opportunities for catching and cultivating brackish and marine species Potential species Penaeusvannamei (Western White Shrimp) Penaeus monodon (Tiger Shrimp) Chanos chanos (Milk Fish) Mugil cephalus (Mullet) Tilapia nilotica (Tilapia)

23. 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

24. EFFECT ON SUNDARBAN FISHERIES Sea level rise may destroy the mangrove forest as well as destroy the marine fish nursery ground Highly vulnerable to sea level rise and will be disappear by 1 meter rise of the sea level

25. 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.

26. 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.

27. CONCLUSION It might bring economic hardshipor might increase the opportunity to higher fish productionthrough adaptive measure and increase the economic growth. But the detailed effects on climate change affecting the fisheries sector is yet uncertain. Bangladesh economy is vulnerable to climate change impact, which could affect our food security and level of poverty by elevating stress on fisheries production

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