Blasts, often from dynamite, leave craters in coral reefs and kill far more fish than can be harvested. In many places, the tourism industry serves as a powerful voice against blast fishing, which could scare divers and other visitors away. Some nations have successfully clamped down on the practice, which is generally illegal, but it continues in areas where explosives are available and people are desperate.
The effects of blast fishing can be horrifying. Only a portion of the fish that are killed is retrieved because many sink to the bottom. Their air bladders,which help fish remain buoyant, and other internal organs can rupture. Blast fishing is not new. It was introduced to many parts of the world by European armies.In Lebanon, for example, blast fishing spread after French soldiers demonstrated the technique.
Lebanon continues to struggle to contain the practice although it is illegal. Culprits seek out areas where fish congregate, and then throw a homemade bomb among them. The explosions are generally easy to spot, but over the past decade or two, some fishermen had taken to dropping explosives deeper and at night when detection is less likely. Some Lebanese fishers use lights at night to attract small fish before detonating the charge.
Tanzania has seen a resurgence in blast fishing over the last decade as mining and construction activity in the country has increased the availability of dynamite. Fishermen often dynamite around coral reefs,where nets might snag. The Tanzanian coast also has relatively few fish, so fishers try harvest anything they can. A pilot acoustic study over six weeks last year in Tanzania for the World Wildlife Fund, an environmental group, estimated that 19 blasts per day occurred in one small stretch of water not far from Dar es Salaam, the largest city. More blast-detection microphones will be deployed soon.
The Tanzanian government and tourism officials would like to combat the problem, but lack resources. The destruction of small fish and coral reefs receives far less attention than another environmental problem: the poaching of elephants and other wildlife. This spring the Tanzanian government plans to begin a $1 million initiative to reduce dynamite fishing.
Kenya, concerned about terrorist attacks, has cracked down on the availability of explosives, and has essentially eliminated dynamite fishing. Experts say that blast fishing remains common in parts of Southeast Asia, particularly Indonesia and the Philippines, while other countries in the region have made progress in stamping it out.
New York Times article: The Horrors of Fishing with Dynamite