Socio-economic development which is reflected by the increase in the number and density of the human population, and the development of the global economy through growth of gross national income has a significant impact on the reduction of biodiversity. The increase in social and economic development has resulted in an increased need for the construction of human settlements, cultivation of food and other needs which will make life more comfortable (road construction, etc.). This leads to fragmentation of habitats, or deforestation in order to create new living spaces. The increase in trade and human migration increases the number of invasive species. The ultimate consequence is the reduction of biodiversity. Our needs may also lead to overexploitation of resource. Since all these resources are non-renewable or slow-renewable, it's necessary that we reduce the use of these resources and move towards sustainable development. Should a key species become extinct this may lead to complete collapse of ecosystem and its health. It is difficult and expensive to deal with this problem once it happens. Therefore, it is necessary to explore the relationships within the ecosystem, paying special attention to the key species which are never to be removed from the habitat. Some key species might have already become extinct, and the consequences of that will be seen in a few decades. Then it will probably be too late to react. The phenomenon of the sixth extinction coused by humans, which is manifested with a delay (through "invasion debt" and "extinction debt") is a major problem for the health of the ecosystem, because we cannot be sure what will the consequences of losing certain species be on wildlife and ecosystem. This paper has attempted to increase awareness of these problems and find a solution by introducing drastic measures that will lead to protection of species and the environment.