Demetres is the CEO of WWF Greece, a position he has held since 1998. Over the last few years, he has worked on key policy issues linked to natural resources, climate change, energy issues, and sustainable development, at both national and European levels. He has served on a number of national and international committees dealing with these issues. He is presently also chairing the WWF Mediterranean Marine Initiative, a concerted effort of the WWF network to conserve the region’s valuable marine and coastal ecosystems.

Demetres holds a B.Sc. (Hon) in Marine Biology from QMC, London University, and an M.Sc. in Fisheries Biology & Management from the University College of North Wales, Bangor.