The United Nations proclaimed May 22 The International Day for Biological Diversity to increase understanding and awareness of biodiversity issues. The theme for the International Day on Biological Diversity in 2009 is invasive alien species - one of the greatest threats to biodiversity, and to the ecological and economic well-being of society and the planet.

In terms of biodiversity, Croatia is one of richest Europaean countries. Great diversity of habitats, including marine and suterranean habitats resulted in a variety of species many of wich are endemic.