Tritonia Scientific Ltd has identified a potential flapper skate (Dipturus intermedius) egg nursery in Scapa Flow during a detailed seabed habitat survey undertaken in May 2025.
If confirmed, the site would represent only the second flapper skate egg nursery discovered anywhere in the world, following the identification of the first known nursery site at Red Rocks on Scotland’s west coast in 2019.
The discovery was made as part of early planning work for a potential new designated anchorage. Tritonia Scientific was commissioned by Orkney Islands Council’s Marine Services team to carry out a comprehensive seabed habitat survey that combined multibeam echosounder and georeferenced high-resolution underwater video to generate 3D digital photogrammetry models that facilitated accurate and precise counting and mapping of the egg aggregations. The work was carried out as part of contract with OIC Marine Services.
During the survey, Tritonia’s team recorded a high concentration of flapper skate egg cases in a discrete area of the study site. In total, 95 confirmed flapper skate egg cases were identified, along with a further 52 egg cases considered highly likely to be flapper skate. The density and distribution of the eggs indicate that the area may function as an important egg nursery for the species.
Flapper skates are listed as Critically Endangered and are recognised as a Priority Marine Feature (PMF) in Scotland, meaning they are afforded policy protection under the National Marine Plan. The identification of a potential nursery site therefore represents a significant contribution to the understanding of the species’ distribution and habitat use in northern Scotland.
Tritonia Scientific specialises in marine habitat surveys, underwater video and stills acquisition, and environmental monitoring for offshore, coastal and nearshore projects. This discovery reinforces the importance of high-quality ecological data in revealing previously unknown aspects of Scotland’s marine environment and ensuring vulnerable species and habitats are appropriately protected.
Links: https://www.orkney.gov.uk/latest-news/flapper-skate-egg-nursery-site-discovery-in-scapa-flow
