The diversity of species has decreased massively during the last century. Despite the array of legal instruments aiming at conserving natural resources applied since the middle of the 20th century the eradication of species has not been hindered. There may be several explanations for why the instruments have not been successful in hindering the decreasing diversity. One proposition for the failures is the lack of a holistic approach in regarding ecosystem characteristics such as inter-species and habitats relations. Another proposition is that the legal system should have an adaptive capacity to deal with complexity and uncertainty. The purpose of this paper is to assess the adequacy of the legal instruments for the protection of wildlife and fish species within the Swedish jurisdiction with reference to these two propositions. The results of the paper show that the legal instruments for the protection of species mainly are concerned with the rational use or protection of a certain species rather than on the sustainability of ecosystems. There is also a lack of adaptive elements in the legislation, such as the lack of legal requirements on monitoring of the conservation status of species. The conclusion of the paper is thus that a legislative approach which is more holistic and more adaptive is necessary; otherwise there is a risk that the preservation of biodiversity will be further frustrated.