Impact of Climate Change on Fisheries and Aquaculture Activities in Southern Iraq

The impacts on aquaculture and fisheries sectors from climate change in southern Iraq will likely to be both positive and negative arising from direct and indirect impacts on natural resources. The main elements of climate change that could potentially impact fisheries and aquaculture activities in the southern part of Iraq are temperature, rain patterns, shortage of freshwater, circulation, upwelling, sea level rise and sea water intrusion in the estuarine areas. Impacts on aquaculture production, aquaculture dependent livelihoods and indirect influences through availability of feed ingredients are discussed. Global warming is likely to be small on aquaculture practices. It may be positive by enhancing growth rates of cultured stocks or negative through impact on water availability, weather patterns, stratification and eutrophication in lentic waters. Based on current practices of fish culture in Iraq, that is predominantly based onspecies feeding low in the food chain, the greater availability of phytoplankton andzooplankton through eutrophication could possibly enhance production.The predicted water stress is thought to result in decreasing water availability in major rivers which can affect that used for aquaculture. There is a need for 11,500 cum/m3 in extensive fish culture and 30,100 cum water / ton fish in intensive fish production.Non consumptive uses of water in aquaculture, such as cage culture and the use of small lentic waters for culture systems based on naturallyproduced feed within the water system, are being encouraged.The predicted reduced water availability in Tigris and Euphrates river system and Shatt Al-Arab Estuary has to be considered in conjunctionwith saline water intrusion in the rivers and adjoining wetlands.Sea level rise and consequent increased salt water intrusion in Shatt Al-Arab estuary imposes adaptations to the related impacts by operations that culture species with high salinity tolerance.Fisheries in small lakes and rivers with high temperature and precipitation changes are most responsive to climatic variables than those of large lakes and rivers. Fisheries in estuaries impacted by sea level rise or decreased river flow are more impacted than marine fisheries which are mainly affected by human interventions rather than climate changes.Effects of climate changeon aquatic ecosystems will occur through increased water temperature, decreased oxygen levels and the increased toxicity of pollutants. Increasingtemperatures will have negative impacts on the physiology of fish because of limitedoxygen transport to tissues at higher temperatures. These constraints onphysiology will result in changes in distributions of both freshwater and marinespecies, and likely cause changes in abundance as recruitment processes areimpacted. Changes in the timing of life history events such as short life span and rapid turnover of small pelagic fishspeciesare expected.Changes in abundance will alter thecomposition of marine and freshwater communities, with possible consequencesfor the structure and productivity of these ecosystems.In lentic systems eutrophication and stratification become more pronounced with a consequent impacton food webs and habitat availability and quality.Regarding freshwater systems, there are specific concerns over changes in timing,intensity and duration of floods, to which many fish species are adapted in termsof migration, spawning and transport of spawning products as a result of climatechange. It is important to develop management systems capable of addressing theneeds for fresh water by fish. Combined effects of changes occurred in the marine environment, namely circulation, temperature, nutrients, primaryproduction cascade up the food web to influence prey availability and habitatconditions for fish.Greatest impacts likely on coastal species and subtidal nursery areas and coastal and demersal species rather than pelagic and deep-sea species. The abilities of marine and aquatic organisms to adapt and evolve according to climatic changes needs more research on the physiology and ecology of freshwater, marine and estuarine fishes.Organisms have specific ranges of environmental conditions to which they are adapted and within which they perform optimally.