SHAH BUNDER (AFP) - Millions of people may be struggling to survive after countrys worst humanitarian disaster in history, but fishermen are hoping to reel in the catch of a lifetime. Villagers who eke out a basic existence in the Indus River delta near the Arabian Sea see a glimmer of rare hope - more fish in the water after devastating floods that affected an area the size of England. The river has met the sea, said Abdur Rehman, 45, who owns a small fishing boat in the sparsely populated village of Shah Bunder, 210 kilometres from Karachi. It will increase the size and number of fish, which means we will have a great catch in the future, said Rehman. The United Nations has issued a record two-billion-dollar appeal for funds to deal with the aftermath of the disaster, which UN agencies say affected 21 million people and left 12 million in need of emergency food aid. Ive never seen such a flood in the river in my life. But my father told me that whenever river water meets the sea, it creates a lot of fish, said 18-year-old Jan Mohammad. Offering no scientific explanation, he adds: There is a magical smell in the river water which increases fish in the sea. But Tahir Qureshi, director of coastal ecosystems at International Union for Conservation of Nature, said merging fresh and seawater could indeed spell a more prosperous future for the fishermen. Freshwater brings nutrients for sea species, which make them stronger, increases their size and capability of breeding, thus making the sea rich. The Indus River delta is the fifth largest in the world. It covers about 41,000 square kilometres, and is approximately 210 kilometres wide where it meets the sea. For the last seven years poor rains have kept river levels low, hitting the delta ecosystem as the sea has eroded more and more land. The paucity of freshwater in the delta has affected mangrove forests, sea species and allowed the salty water to creep onto the farmlands, said Qureshi. Seawater has encroached 57 kilometres onto the river course since the 1950s and the process has increased significantly since the early 1990s, he said. The silent ecological disaster has destroyed large areas of farmland that would once have produced banana, papaya, coconut and sugarcane. The freshwater flooding, he said, will strengthen mangroves, enrich aquifers and offset sea erosion. Mohammad Ali Shah heads the Pakistan Fisherfolk Forum organisation, which represents around one million fishermen, most of whom live in Sindh. A negligible amount of water in the river for the last two decades has caused huge damage to the riverine forests and overall ecosystem. As a result around one million fishermen faced hard times, he said. Shah maintained that the floodwaters would enrich lakes and enhance the fortunes of fishermen. Our lakes have been devoid of water, but now they are flooding. The flood has caused huge damage elsewhere but that will benefit the fishing community in the long run. Aslam Khwaja, who works for local charity, the Peoples Development Foundation that has been conducting relief efforts in southern Sindh, also told AFP that fishermen saw a silver lining to the cloud of disaster the floods have brought. Fishermen are really happy that freshwater will bring them better fortune in the shape of better fish catches, mangrove strengthening and a yearning for fresh drinking water, he said. Rehman hoped that fishermen could even double their ordinary earnings of 3,000 to 5,000 rupees a month, which would be a welcome break to help offset rising prices of fuel and food that have squeezed them. We expect a better income at least for a few months while the effect of the freshwater on the sea remains, said Rehman. Jan Mohammad noted the irony of their fortune. The floods put smiles on our faces, but Im not that happy - because millions of people lost their shelter and livelihoods.