In positive conservation news, scientists have announced that the decline in angelsharks off the Welsh coastline may be less than previously thought.
In a new study published in People & Nature, experts from Zoological Society of London (ZSL), Natural Resources Wales (NRW) and Welsh fishing organisations have shown that previous figures around how much angelsharks (Squatina squatina) have declined in Wales might be overestimated.
Other papers had estimated that angelsharks have declined by 70% in Wales since the 1960s based on a drop in the likelihood of fishers coming across them. But the reduction may actually be because fishing practices have changed: fishing areas are overlapping less with the sharks' habitat and angling efforts have reduced. The lower chance of encountering these animals could be more to do with the challenges researchers face in monitoring them.
“Identifying how changes to fishing practices over the last 51 years have impacted our ability to monitor them indicates that there may be more angelsharks swimming off the Welsh coast than we previously thought – we're just having a harder time spotting them,” says Francesca Mason, lead author and ZSL researcher at the Institute of Zoology’s Ocean Predator Lab.
"While this is a good sign if less angelsharks are being caught accidentally, it also means we now need new ways to monitor them to build a more accurate picture of how these sharks are doing.”
These flat, diamond-shaped sharks are critically endangered. "Angelsharks globally have been pushed to the brink of extinction due to damage to their underwater habitat," says Mason. "This finding offers hope."
Angelsharks are a light-brown colour, covered in speckles to help them camouflage against the sandy seabed. They sometimes even bury themselves under the sand and wait, unseen, for prey to pass by that they can ambush.
Because they're so hard to find, scientists often gather data based on reports of angelsharks being accidentally caught by fishers.
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But there are other methods that can be used to monitor the presence of these sharks, such as analysing water samples for traces of environmental DNA (eDNA), which can give a clearer picture of which species recently visited an area. As they swim along, the animals slough off dead skin and other genetic materials that can be picked up through eDNA analysis.
"With their excellent camouflage, one of the hardest challenges we face studying angelsharks is simply finding them," says Jake Davies, technical specialist for Project SIARC at ZSL and NRW. "eDNA allows us to study species without having to spot them.
"By studying eDNA in Cardigan and Carmarthen Bays, we’ve confirmed the presence of a range of native sharks, skates and rays - including angelsharks - in these more turbulent waters where other monitoring methods aren’t as effective," adds Davies.
"With their large, flat fins, angelsharks are unlike any other shark we see here," says co-author Charlie Bartlett, a charter fisher who shares information and pictures of his angelshark encounters with Angel Shark Project: Wales to help their research. "This information is not just important for the species itself but also inspires the next generations to learn more about fishing heritage in Wales and the local marine environment," he says.
By working with fishers like Bartlett, and exploring technological advancements, scientists can learn more about the status of endangered species, such as angelsharks, which helps their mission to protect them.
Mason adds: “The work also highlights why conservation works best when we bring people together and combine the knowledge of those living alongside these creatures with cutting-edge research and science.”
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