The diversity and proliferation of life in the oceans is breathtaking (McIntyre, Reference McIntyre2010). Life under the sea is fascinating and captures public imagination. This is exemplified in popular fiction from the mid 1800s in the novels of Herman Melville (Moby Dick, 1851) and Jules Verne (20,000 leagues under the sea, 1870) to the television programming of today (https://www.bbc.co.uk/programmes/p05qrr1q). It is becoming clear, however, that the world is experiencing an unprecedented loss of biodiversity (Vos et al., Reference Vos, Joppa, Gittleman, Stephens and Pimm2014) and there is evidence that this also applies in our oceans and consequently their ability to provide ecosystem services (Worm et al., Reference Worm, Barbier, Beaumont, Duffy, Folke, Halpern, Jackson, Lotze, Micheli, Palumbi, Sala, Selkoe, Stachowicz and Watson2006). It is our privilege as marine scientists to explore these little known environments, to extend our knowledge of their diversity, to investigate the organisms that live there and to determine how they function. Such research is exemplified in this issue of The Journal of the Marine Biological Association of the United Kingdom. The beauty and complexity of gelatinous zooplankton is highlighted on our front cover and in their paper Corrales-Ugalde et al. (Reference Corrales-Ugalde, Quesada, Naranjo-Elizondo and Cortés2018) expand our knowledge of these delicate organisms through opportunistic sampling in an underwater tourism vehicle. Detailed work of Kornienko et al. (Reference Kornienko, Golubinskaya, Korn and Sharina2018) reveals the complete larval development of Leonardsaxius amurensis for the first time and Plotkin et al. (Reference Plotkin, Gerasimova and Rapp2018) provide a systematic overview of the Polymastiidae of the Nordic and Siberian seas.

Interactions between organisms is addressed in several papers. The intense competition between barnacles on crowded rocky shores is examined by Gordon & Knights (Reference Gordon and Knights2018). The importance of host-parasite interactions in the amphipod Gammarus insensibilis found in UK saline lagoons is the focus of a study by Gates et al. (Reference Gates, Sheader, Williams and Hawkins2108). Crickenberger et al. (Reference Crickenberger and Wethey2018) explore how temperature influences the fertilization and success of early planktonic larval stages of Semibalanus balanoides and the consequences for settling and subsequent population distributions. Those of us who have dived on biogenic reefs of various sorts are aware of the fragile and complex nature of these systems and the composition and management of Modiolus reefs from around the UK is considered in Brash et al. (Reference Brash, Cook, Mackenzie and Sanderson2018). Our attention is drawn to the impact anthropogenic activities have had on deep-sea areas in the paper of Mecho et al. (Reference Mecho, Aguzzi, De Mol, Lastras, Ramirez-Llodra, Bahamon, Company and Canals2018) exploring the north-western Mediterranean Sea.

Finally on the subject of anthropogenic changes impacting our oceans, Westgarth-Smith (Reference Westgarth-Smith2018) draws to our attention the need to raise public awareness of ocean acidification. In his paper he highlights the paucity of public knowledge of and engagement with the mechanisms and effects of this process as gauged through examination of school curricula and public debate. He concludes with encouragement to us as scientists to produce a press release whenever publishing a paper on the topic as a means of increasing public awareness of the importance of this phenomenon. This is a point of good practice that could be more widely applied to our scientific publishing. In return for the privilege of often publicly funded research we should seek to inform the public and maintain their fascination with the oceans and appreciation of our potential effects on them. As a Journal we are keen to support this advice and are happy to work with authors on revealing their results to a wider audience.