Other impacts of blast fishing in the area include reports that citizens have died or lost limbs due to the blasting. The northern part of the country has many beautiful beaches and uninhabited islands. However, many investors feel that tourists are discouraged due to the fish blasting. In Tanzania, coral reefs are essential for both ecological and socio-economic reasons. They are full of fish, lobsters, prawns, crabs, octopuses, mollusks, and sea cucumbers. In addition, coral reefs are one of the major tourist attractions in Tanzania. The coastal tourism provides a living for the people as well as foreign currency for the country. However, there has been an increase in the people living along the coast which has led to a large demand for fisheries. It has led to overexploitation and destructive fishing practices. Blast fishing has been practiced in Tanzania since the 1960s. It was during the 1980s and 1990s that blast fishing was at its peak in Tanzania. For example, in Mnazi bay, Mtwara, 441 blasts were recorded in two months in 1996, and 100 blasts were witnessed through one six-hour period in Mpovi reef. A 1903 short story by Frank Norris titled "The Passing of Cock-Eye Blacklock" describes efforts to end blast fishing on the American River. Besides the effectiveness in killing or stunning the fish, another problem with blast fishing is the inefficiency of retrieval. For every ten fish killed, only one or two float to the surface due to damage caused to the internal air bladders of the fish. The rest sink to the bottom. Naval battles also tend to kill fish with the same effect of blast fishing from shells exploding in the water.