After obtaining his Ph.D. in 1991 at University of Seville, he worked on different aspects of microbial ecology during postdoctoral stays in Amsterdam University (The Netherlands) and Cornell University (USA), and obtained his permanent position as tenured scientist at IRNAS in 1996. He has worked as a visiting researcher in the Swiss Federal Institute of Aquatic Science and Technology (EAWAG) in Dübendorf, Swizerland (1997), in the Massachusetts Institute of Technology, USA (2003), and in the University of Oxford, UK (2009 and 2012). In 2009, Dr. Ortega promoted to Senior Researcher at CSIC. 

He has also wide experience in leading national and international research projects, having lead 19 projects (total cost 2,8 million euro) since 1997 (see the most recent projects below), and he is associate to the University of Seville in the PhD programmes “Integrated Biology” and “Natural Resources and Environment”.

Dr. Ortega-Calvo was, in 2016/2017, the president in Europe of the Society for Environmental Toxicology and Chemistry (SETAC Europe), and from June 2017 to June 2023, a member of the Stakeholder Bureau from EFSA (European Food Safety Authority), representing academic stakeholders. Since November 2017, he is a member of the External Science Advisory Panel (ESAP) at Long Range Research Initiative of the European Chemical Industry Council (CEFIC-LRI). J.J. Ortega is Associate Editor of the journal Science of the Total Environment (Elsevier, Q1, environmental sciences -JCR), since May 2018, and Critical Reviews in Environmental Science and Technology (Taylor& Francis, Q1, environmental sciences, JCR), since August 2022. 

He is the programme committee chair of the 34th SETAC Europe congress in FIBES, Seville (May 5-9, 2024). It will be a premier international event, with the participation of approximately 2,500-3,000 delegates from around the world.