Life 2014, 4, 566-585; doi:10.3390/life4040566 life ISSN 2075-1729 www.mdpi.com/journal/life Article Mud Volcanoes of Trinidad as Astrobiological Analogs for Martian Environments Riad Hosein 1 , Shirin Haque 2,†, * and Denise M. Beckles 1,† 1 Department of Chemistry, University of the West Indies, St. Augustine, Trinidad, West Indies, Trinidad and Tobago; E-Mails: riadhosein83@gmail.com (R.H.); denise.beckles@sta.uwi.edu (D.M.B.) 2 Department of Physics, University of the West Indies, St. Augustine, Trinidad, West Indies, Trinidad and Tobago † These authors contributed equally to this work. * Author to whom correspondence should be addressed; E-Mail: shirin.haque@sta.uwi.edu; Tel.: +1-868-662-2002 (ext. 83113); Fax: +1-868-662-9904. External Editors: Dirk Schulze-Makuch and Alberto G. Fairen Received: 9 June 2014; in revised form: 8 September 2014 / Accepted: 23 September 2014 / Published: 13 October 2014 Abstract: Eleven onshore mud volcanoes in the southern region of Trinidad have been studied as analog habitats for possible microbial life on Mars. The profiles of the 11 mud volcanoes are presented in terms of their physical, chemical, mineralogical, and soil properties. The mud volcanoes sampled all emitted methane gas consistently at 3% volume. The average pH for the mud volcanic soil was 7.98. The average Cation Exchange Capacity (CEC) was found to be 2.16 kg/mol, and the average Percentage Water Content was 34.5%. Samples from three of the volcanoes, (i) Digity; (ii) Piparo and (iii) Devil’s Woodyard were used to culture bacterial colonies under anaerobic conditions indicating possible presence of methanogenic microorganisms. The Trinidad mud volcanoes can serve as analogs for the Martian environment due to similar geological features found extensively on Mars in Acidalia Planitia and the Arabia Terra region. Keywords: mud volcanoes; Trinidad; chemical profiling; microbial life; analog; Mars OPEN ACCESS