Conservation and social-ecological systems in the 21st century of the Anthropocene era Authors Juan Carlos Castilla Abstract Conservation is a 'slippery' concept that can be interpreted in many different ways. This essay reviews historical approaches to conservation and its romantic (even patriotic), initially equitable connotation of preservation, as proposed by 18th century North American philosophers and naturalists. The opposing view is presented as well, i.e., that the real world is not the same for eternity but dynamic, and the product of the interaction of society, industry and the state, as proposed by European philosophers around the same time. In the context of the Anthropocene era of the 21st century and based on scientific, societal and ethical grounds, the aims and spatial scales of conservation are discussed, as are the connections between conservation, sustainability, and economic equity. Two options to deal with the conservation of nature in the Anthropocene are explored herein. First, the view held by the 'deep ecology' movement, and second, that represented by the Millennium Ecosystem Assessment project. A personal view on the priorities of what, where, and how to conserve is presented. The long-term social-ecological sustainability and conservation of coastal marine resources in Chile is discussed as an example of a modern and comprehensive approach to conservation. Finally, this essay calls attention to Professor Ramon Margalef (1993), specifically, his visualization of the complex interplay among humans and nature, which is very much in line with the views of the author. Downloads PDF Issue Vol. 8 No. 1 (2012) Section Margalef Prize Lecture 2011 License This work is subject, unless the contrary is indicated in the text, the photographs or in other illustrations, to an Attribution —Non-Commercial— No Derivative Works 3.0 Creative Commons License, the full text of which can be consulted at http://creativecommons.org/licenses/by-nc-nd/3.0/. You are free to share, copy, distribute and transmit the work provided that the author is credited and reuse of the material is restricted to non-commercial purposes only and that no derivative works are created from the original material.