Environmental Threats To The Great Barrier Reef - Overfishing

Overfishing

The unsustainable overfishing of keystone species, such as the Giant Triton and sharks, can cause disruption to food chains vital to life on the reef. Fishing also impacts the reef through increased pollution from boats, by-catch of unwanted species (such as dolphins and turtles) and reef habitat destruction from trawling, anchors and nets. Overfishing of herbivore populations can cause algal growths on reefs. The Batfish Platax pinnatus has been observed to significantly reduce algal growths in studies simulating overfishing. Sharks are fished for their meat, and when they are part of bycatch, it is common to kill the shark and throw it overboard, as there is a belief that they interfere with fishing. As of 1 July 2004, approximately one-third of the Great Barrier Reef Marine Park is protected from species removal of any kind, including fishing, without written permission. However, illegal poaching is not unknown in these no-take zones.