التداعيات المحتملة للتغيرات المناخية على الموارد السمكية فى مصر ومقترحات مواجهتها والتخفيف من اثارها

Possible repercussions of climate changes on fish resources in Egypt and proposals to mitigate their effects

أدت الممارسات الغیر صديقة للبیئة على مدى العقود الماضية، إلـــى زيادة التركیزات العالمية من غاز ثاني أكسید الكربون وغیرها من الغازات التي تسببت في حدوث ما يعرف بظاهرة الاحتباس الحراري في الغلاف الجوي و ما يسببه من ارتفاع في درجة حرارة الأرض، و ذوبان الجلید و ارتفاع مستوى مياه البحار والمحيطات، وتهدید مناطق و اسعة من الأراضي الساحلية والمنخفضة و دلتا الأنهار، وكذلك حدوث موجات جفاف شدیدة في بعض المناطق وفيضانات عارمة في مناطق أخري، و تناقص الفترات شدیدة البرودة، مقابل تزاید الفترات شدیدة الحرارة. وكل هذه التغیرات تؤثر على نطاق واسع على النظم الإيكولوجية، وأنظمة إنتاج الغذاء والتنوع البیولوجي، بما في ذلك المصاید الطبيعبة والاستزراع المائي.

Over the past decades, unfriendly environmental practices have led to an increase in global concentrations of carbon dioxide and other gases that have caused what is known as the phenomenon of global warming in the atmosphere. This is causing a rise in the temperature of the Earth, melting ice and a rise in the level of the seas and oceans that threat large areas of coastal areas, low lands and the deltas of rivers. It also causes severe droughts in some areas and severe floods in others, and a decrease in very cold periods, in contrast to an increase in extremely hot periods. All of these changes have a wide impact on ecosystems, food production systems and biodiversity, including capture fisheries and aquaculture. Water temperature, plays an influential role in the processes of reproduction, growth and migration of aquatic organisms. It negatively or positively affects fish production, its seasonality, stock composition and its distribution. Furthermore, with the increase in temperature, the evaporation process increases and thus the salinity of the water increases that led to a change in the stocks composition and production of salt water species, and a decrease in the production of fresh water fish species, as well as the predominance of warm water species against the decrease of cold water one. Also the increase in temperature reduces the levels of dissolved oxygen, which leads to increased fish mortality, and a decrease in production. Also, the change in the strength and direction of the sea currents that carry nutrients to fish causes drastic changes in the fertile areas. Sea level rise with increasing temperature affects coastal areas, including wetlands, lagoons, sea grass beds, coral reefs, and mangroves, which are feeding or breeding areas for most marine organisms. It also leads to the sinking of coastal areas and salinization of groundwater and harm freshwater fisheries and aquaculture. It also, sinking the lagoons, bays and shallow water bodies that have an important ecological role.

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