The biodiversity in the marine reef ecosystem of the Great Barrier reef in Australia, Queensland has declined due to the increase of crown of thorns star fish. The increase of the starfish is caused by run off during the monsoon season via by fertilizers from agriculture. As a result, the overall population of corals has declined by 25% from the starfish in the last 30 years. The decline of corals will decline the population of other species such as fish and will have a negative affect on other species.