During the last century the variety of species has decreased dramatically and numerous species are today classified as endangered or threatened. Since the middle of the last century, a number of legal instruments concerning the use and conservation of natural resources have been applied, such as protection of individual species and their nests and restrictions on hunting and fishing, without hindering the eradication of species. One proposition for the failures of traditional legal instruments is the lack of a holistic approach in regarding ecosystem characteristics such as inter- species and habitats relations and biodiversity and lack of adaptivity to deal with the dynamics of biodiversity. The objective of the thesis is therefore to describe and assess the adequacy, with reference to diversity and adaptivity criteria, of the existing legal instruments concerning the protection and utilization of species. To achieve the above stated objective environmental legal methodology has been applied. The analysis founds that the legal instruments mainly are concerned with the rational use or protection of a certain species rather than dealing with inter- relations and the sustainability of ecosystems and that that the legal system concerning the protection of species generally lacks adaptive elements. A legislative approach which is more holistic and adaptive is thus necessary: otherwise there is a risk that the preservation of biodiversity will be further frustrated.