What environmental effect did the building of the Aswan Dam in Egypt have?

The construction of the Aswan Dam had significant environmental impacts, particularly on the ecosystem in and around the Nile River and its delta. One notable effect was the disruption of sediment flow, which naturally replenished the nutrient-rich silt that supported the fishing industry. With the dam in place, the natural flooding and sediment deposition that occurred annually were altered. This led to a decline in the mineral and nutrient levels in the water, thereby adversely affecting fish populations and the overall health of the aquatic environment. Consequently, the fishing industry at the mouth of the Nile suffered due to reduced fish stocks and changes in the habitat, making the correct choice reflecting the dam's impact on local fisheries.