What Happens to Fish During Dynamite Fishing?

Dynamite fishing, or blast fishing, is a fishing method that employs the use of explosives to kill or stun fish for easy collection. Although it is generally illegal, blast fishing is a practice that remains fairly popular in the Philippines, in Southeast Asia and in many of the African coastal regions. Blast fishermen use commercial dynamite, but most often, they construct homemade bombs, consisting of glass bottles filled with pebbles and powdered potassium nitrate or else a mixture of kerosene and ammonium nitrate. Blast fishing is a dangerous practice that can have dramatic consequences on fish and their environments.

  1. Dynamite Fishing And Fish Anatomy

    • The underwater shock waves that explosives produce not only stun fish but ultimately cause ruptures in their swim bladders. A swim bladder is a gas-filled internal organ that helps a fish control its buoyancy without expending unneeded energy. When this organ becomes damaged in the underwater explosion, the stunned fish float to the surface, where they are then harvested by hand, by spear or by nets.

    Signs of Dynamite Fishing

    • When law enforcers investigate illegal fishing practices, it's important for them to recognize the signs of blast fishing by examining certain anatomical details exclusive to explosive fishing methods. Aside from ruptured swim bladders, fish commonly have fractured vertebral columns and dislocated abdominal ribs. Burst blood vessels and hemorrhages, as a result of the initial explosion, generally surround these areas of rupture and fracture.

    Unintended Consequences

    • One major problem with blast fishing is its propensity to kill indiscriminately. Blast fishermen target fish that travel in large schools, so that they will pull in a good harvest, however, since the explosives are often unstable and cannot be easily controlled, other fish and marine organisms become innocent bystanders. In many areas where destructive fishing methods are used--especially in those where the activity is not monitored--this leads to a gross reduction of species diversity and richness, which can have negative effects on underwater ecosystems.

    Coral Reefs

    • Destructive fishing methods are among the greatest of threats to coral reefs and their surrounding ecosystems. Blast fishing causes damage to coral reef structure by shattering the reef's calcium carbonate skeleton and creating large craters, essentially destroying the reef faster than it can recover. Such destruction has resulted in the loss--even extinction--of many coral fish species, ultimately reducing fish habitats in areas within close proximity to coral reefs.