June 23, 2026
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Participants of all experience levels visited rocky shores across the country between 23rd and 31st May, united by a shared enthusiasm for exploring the UK coastline. An incredible 3,781 observations of 544 species were recorded during the event.
Records included everything from common shore crabs to extremely rare finds. Observations were submitted and verified through the iNaturalist app, and each species was given a rarity score, with prizes available for top scoring participants.
The data collected provides a national snapshot of intertidal biodiversity, with particular valuefor monitoring changes in species distributions, including the spread ofnon-native marine species.
There were some amazing species recorded, including a rare shrimp (Philocheras fasciatus) found off the Hampshire coast, which was among the highest scoring species. There were also multiple records of the candy striped flatworm (Prostheceraeus vittatus),whose vivid appearance made it one of the most photographed species of the week.
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Participants recorded 19 of the 47 targeted marine non-native species, with wireweed (Sargassum muticum) being the most frequently recorded. Some particularly fascinating non-native species were found, including the stalked sea squirt (Styela clava) and red ripple bryozoan (Watersipora subatra), both of which had top rarity scores.
There were exclusive prizes for the top scorers across the 9 participating regions, whose dedication and consistent effort set an inspiring standard throughout the challenge. Kamil Majewski was the overall winner, collecting 287 records in the South West of England and scoring an incredible 3,344 points.
"The National BioBlitz 2026 showcases the power of coordinated citizen science in revealing the richness and change of UK intertidal biodiversity. From Cornwall to Shetland, participants, volunteers, and hub leaders contributed thousands of records that strengthen our national understanding of coastal wildlife. We are deeply grateful to everyone involved, including our funders and partners, whose support makes this work possible."
