Invasive species are normally defined as creatures with high reproduction rates and few natural predators. Their existence in an ecosystem can destroy an entire food chain by overconsumption of a particular population due to their vast numbers. This paper explores the effects the crown of thorns starfish has had on the great barrier reef in the past and the present such as its effects on the ecosystem and impact on human lives. The paper also explores patterns regarding climate change and other human impacts and how that may affect the growth of the crown of thorns. Finally, this paper covers and evaluates the proposed solutions to combat the starfish by weighing their feasibility and how well they could work if they were put into practice. The purpose of this paper is to understand how the crown of thorns is a threat to the great barrier reef and possible methods to combat it.