Destructive Fishing

Some fishing practices, both legal and illegal, can have very damaging effects on a range of ocean habitats. For example, coral reefs and seagrass beds are important habitats and breeding grounds for fish, but they are fragile and easily affected by destructive fishing practices.

Here are some examples of fishing practices that come with a cost to the environment. Although many of these methods are illegal in many parts of the world, they are still widely used:

Bottom Trawling – Trawling is the most destructive human activity affecting the world’s oceans. Trawlers sweep large nets along the ocean bottom, catching commodity species but also everything else in their path, tearing up the seafloor and delicate marine ecosystems in the process. A single net can snare a tonne and a half of coral every hour.

Fine Mesh Nets – These nets have a tiny mesh size which means that everything gets caught, including the very smallest fish. As small fish are often juveniles that have not had the chance to breed, this kind of fishing very quickly depletes or eradicates the local population of that species.

Ghost Nets – This term is used when fishing gear is lost or abandoned at sea. The nets and lines drift in the ocean currents and continue to entangle a whole variety of animals which eventually die of suffocation or starvation. Whales, dolphins, sharks and turtles are some of the many species caught this way.

Dynamite Fishing – Dynamite is detonated underwater causing much of what is caught in the blast to die. The fish float to the surface where they can then be collected by the fishers. This illegal method destroys the whole underwater environment.

Cyanide – Divers use a poison, sodium cyanide, to stun fish without killing them so that they are easy to catch. It is estimated that for each fish killed using cyanide, 1 metre-squared of coral reef is killed.

Information on SUSTAINABLE FISHING