The major human impacts on the Great Barrier Reef Ecosystem are over-fishing, pollution and global warming. A fifth of the reefs were destroyed and aren’t recovering, quarter are endangered and another quarter will most likely face a long-term collapse. In addition to that the global warming worsened by human activity created warm temperatures, resulting in negative effect on the ecosystem. Moreover overfishing caused disruption in the food we, and overexploitation depletes the keystone species and animal life. Plus pollution is also a threat to the reefs health, because the runoff and sedimentation from the farms is destroying coral reefs.