Hong Kong Jellyfish Project 2021 Website and iNaturalist observations

Jellyfish are charismatic and notable organisms within marine ecosystems, yet our understanding of their occurrence is poorly developed. The potential for citizen science to monitor phenomena associated with these Cnidarians over large spatial scales has been recognized in an increasingly broad array of locations, including the Mediterranean, South Africa, and the UK. Here, we were interested if such an approach could be used in Hong Kong. The Hong Kong Jellyfish Project was implemented in early 2021 to study the presence, seasonal abundance, and distribution of jellyfish in Hong Kong’s waters, with sightings submitted by citizen scientists through a project website, and iNaturalist. During the course of 2021, over 390 observations of jellyfish were submitted through the website and iNaturalist project, with 18 species recorded as present, and two new species records for Hong Kong documented. There was a seasonal trend in observations, with most jellyfish seen in the summer months of March-May. Finally, there was a broad geographical distribution of observations throughout Hong Kong’s coastal waters, with more observations made in the south/east. Together, these observations gathered by citizen scientists indicate a broad distribution of jellyfish – and the occurrence of previously undocumented species – in Hong Kong’s waters.