<P> In northern Tanzania, blast fishing, which is illegal, has resurfaced in recent years as a key danger to its coral reefs . This has occurred even though major institutions like local communities and the district government have been put in place for enhanced fisheries management . The damage of blast fishing in the area has contributed to unstable coral reefs, discouragement of tourism investors, and a threat to the habitat of coelacanths in the region . 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 and tourists are discouraged due to the fish blasting . </P> <P> 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 practised 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 6 hour period in Mpovi reef . </P> <P> A 1903 short story by Frank Norris titled The Passing of Cock - Eye Blacklock describes efforts to end blast fishing on the American River . </P> <P> Despite the effectiveness in killing or stunning the fish another problem with blast fishing is the inefficiency of retrieval . For every 10 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 . </P>

Which of the following chemicals is used to paralyze and catch reef fish mostly in se asia