An unexploded home made bomb, photographed at the popular Dar es Salaam dive site, Bongoyo Patches, lays benign nestled among corals. Bombs such as these are made with a water bottle containing a mixture of fertilizer and diesel. They are used by unscrupulous dynamite fishermen to the shoals of small fish, thereby chumming the water and attracting larger fish. Once the larger fish arrive additional bombs are thrown into the water. Most of the fish killed by the shock waves, sink to the bottom of the ocean and are not recovered by the fishermen. Entire breeding populations of some fish species are currently being wiped out by this indiscriminate method of fishing.