Imagine slipping beneath cold coastal waters every month for nearly three years, returning to the exact same patch of seafloor in search of something that rarely moves and is often hidden in plain sight. There are no dramatic chases, no guarantee of finding what you came for. Instead, researchers and volunteer divers have been returning to this spot looking for something far more subtle but also far more rewarding: the egg cases of the critically endangered flapper skate, one of the largest skate species in the world.
Those repeat searches have now provided one of the most detailed looks yet at a known reproductive habitat for the species. And this new study represents the first long-term, multi-method monitoring effort focused on an essential fish habitat used by flapper skates (Dipturus intermedius) for laying eggs. Over a period of 31 months, community scientists worked alongside researchers to monitor a designated egg-laying site, documenting not only the presence of egg cases but also the broader ecosystem surrounding them.
The flapper skate was once widespread across parts of the northeastern Atlantic. Today, however, it is considered critically endangered. Like many large-bodied sharks, skates and rays, flapper skates grow slowly, mature late and produce relatively few offspring; these life history traits make populations especially vulnerable to overfishing and habitat disturbance. Protecting areas where they reproduce is therefore a major conservation priority. To better understand how this habitat is being used, volunteer divers conducted monthly SCUBA surveys within a defined area known to contain flapper skate egg cases. Whenever they found viable egg cases, they carefully measured them and collected genetic samples using non-invasive techniques. At the same time, they also recorded observations about the surrounding marine environment, creating a broader picture of the ecosystem in which these developing embryos were growing. To complement what people could see underwater, the research team also deployed baited remote underwater video systems, commonly known as BRUVs.
These camera systems recorded 13 different species during 10 deployments, helping to characterize the wider ecological community. And the SCUBA survey efforts revealed that during the study period, researchers documented 16 newly laid egg cases within the monitored site. This was not confined to a single season, as egg laying occurred during spring, autumn and winter across multiple years, suggesting that the habitat remains important over extended periods rather than serving as a temporary reproductive hotspot. The viable egg cases were also confirmed to hatch successfully during all four seasons, indicating that the site is not merely a place where eggs are deposited but where embryos survive long enough to emerge as young skates. In the conservation world and scientific terms, that distinction matters because a habitat only fulfills its role as a nursery if it contributes to the next generation. Interestingly, despite the site’s importance as an egg-laying habitat, no adult flapper skates were captured on camera. Which might seem weird. If skates are laying eggs there, shouldn’t they be easy to spot? Not necessarily — marine animals can be notoriously difficult to observe directly, even in places they use regularly! So adult skates may visit briefly to reproduce before moving elsewhere, may avoid cameras or simply not be present during deployment periods. This just goes to show that no single method captures the full story, which is why it’s so important to use complementary tools in research like this. And this message became clear when researchers turned to another tool: acoustic monitoring. An underwater receiver placed near the site detected multiple visits by two adult male flapper skates that had previously been tagged elsewhere in the region, so although the skates never appeared on camera, their electronic tags revealed that they were actually returning to the habitat.
Together, these observations provide compelling evidence that the site functions as an active and repeatedly used reproductive habitat. And, the researchers stress, the study underscores something increasingly important in conservation science: the value of community participation. Long-term monitoring projects are often expensive and difficult to sustain. Researchers also cannot be everywhere at once, particularly in marine environments where fieldwork requires specialized equipment, training and favorable weather conditions. Yet local divers and community scientists can help fill critical gaps; in this case, they contributed consistent observations over more than two and a half years, generating data that would have been challenging to collect otherwise. This effort demonstrates how conservation goes beyond depending on big government grants or impressive-looking vessels and sometimes depends on people who know their local waters and are willing to invest time in understanding and protecting them. Around the world, scientists are working to identify and protect essential habitats for sharks, rays and other marine species. But finding these locations is often only the first step. Understanding how they are used, whether they remain active over time and whether they successfully support reproduction requires sustained monitoring. This is when scientists should be turning to the local communities to collaborate on better understanding and ultimately protecting these waters.
For the flapper skate, the findings offer a reason for cautious optimism. The species remains critically endangered, and significant challenges remain, yet the study shows that known reproductive habitats can support successful development and hatching over multiple years. Protecting endangered species is not only about understanding the animals themselves — it is also about understanding the places they depend on, and recognizing that safeguarding those places can be a shared effort between all.