Participatory science communication featured in several sessions and individual papers at the 2021 online conference of the Public Communication of Science and Technology (PCST) Network. This coverage recognises the drive away from linear communication to more participatory forms of science communication. In this special edition we present practice insights, papers and essays that explore participatory science communication. These contributions explore definitions, processes and describe case-studies of participatory science communication which involve a variety of publics, from young school students to Indigenous groups to farmers. In this introductory editorial we reflect on the papers, describe the growth of a participatory approach as part of the continuing evolution of science communication; explore a definition for participatory science communication; and consider some of the key concepts and issues that emerged.

Despite Mexico has coasts in the Pacific and Atlantic oceans, people's connection towards the sea and marine environments is quite poor. Our commentary focuses on Mexico's coral reefs, relevant tropical ecosystems to human and oceanic welfare, and it emerges from the experience of the production of an itinerant coral reefs exhibit in Mexico, committed to the conservation and awareness of this threatened habitat. The UN Decade of Ocean Science for Sustainable Development starts in 2021 and represents an opportunity to increase initiatives for public communication of science on marine and oceanic issues in Mexico and the world.

The National Autonomous University of Mexico (UNAM) is one of the world's single largest employers of science communicators, with over 350,000 students and 40,000 staff. Its science communication activities include five museums (Universum, Museo de la Luz, the Geology Museum, Museo de la Medicina Mexicana and Musem of Geophysics), botanical gardens, as well as a wide range of cultural and outreach activities. It has several programmes for training professional science communicators. The science communication staff are spread across the campuses in Mexico City and four other cities, including writers, explainers, researchers, evaluators, who produce exhibitions, magazines, books, theatre, screenings and science cafés. This activity is diverse and sometimes operates to different agendas.