Like their close relatives, sharks and skates (and the lesser-known Chimaeras), rays are cartilaginous fish, meaning that their skeleton is made of cartilage rather than bone. Cartilage is tough, light and flexible, making them efficient swimmers for hunting prey, escaping predators and embarking on long migrations. Cartilaginous fish have been around for a long time, about 450 million years, outdating the rings of Saturn, the dinosaurs and even trees. They have survived multiple extinction events and diversified into over 1,200 species, occupying every ocean and filling a wide range of niches.
With so much evolutionary history behind them, the common stingray is perfectly adapted to its environment. Their wide, flat body is ideal for gliding through the water, trapping prey on the seabed and laying low to hide from predators. Their mouths are covered in rows of short blunt teeth, forming two crushing plates to break down the shells of the invertebrates they eat, as well as small fish. Surrounding their mouths there are over one thousand tiny pores that can sense electrical and magnetic fields, used to detect movement of prey in the sand and track the magnetic signature of the Earth, which they use to navigate during migrations. Like all rays, their gills are located on the underside of their bodies (called the ‘ventral’ side). To help with breathing when they’re lying still, they pump water through holes, called spiracles, just behind their eyes, supplying oxygen to the eyes and brain. The barbed stingers (rarely a threat to humans) which give them their name, offer protection to their vulnerable rear end. It is a treat to see them in our waters. They can be found across Sussex, from late April until around September.
Stingrays can be confused for their cousins, the skates. There are multiple species of skate found in Sussex year-round. Most easily identifiable is the difference between the whip-like tails (and barbs on stingrays) of the rays and the fleshy (often spiky) tails of skates. A key difference between the biology of the two is that skates lay eggs (also called ‘mermaids purses’, which beach-combers can occasionally find in large numbers across Sussex), while rays give birth to live young.
Sharks, skates and rays are a highly threatened group of animals. The common stingray is listed as Vulnerable on the IUCN Red List, meaning that it faces a risk of extinction in the wild. Across its range in the Atlantic and the Mediterranean, the biggest threat to common stingrays is overfishing. This highlights the importance of effective local fisheries management.
As someone working in fisheries management with Sussex Inshore Fisheries and Conservation Authority (Sussex IFCA), there are currently no concerns over the impacts of the relatively small-scale fishing which occurs inside the Sussex IFCA District and its effects on the inshore population of common stingrays.
However, as someone who cares about the marine environment, I find the threats and populations trends faced by all sharks, skates and rays globally deeply concerning. Sussex IFCA is responsible for managing fisheries in the inshore environment, covering waters up to 6 nautical miles from the shore. This includes introducing byelaws to protect sea fisheries resources, as well as monitoring fishing activity and safeguarding sensitive habitats. The work we do in collaboration with other local organisations, including with SKRP on the monitoring of the Nearshore Trawling Byelaw, helps reduce the risk of stingrays being impacted by fishing gear, while also protecting their prey species and the habitats they rely on. We will continue to monitor fishing activity across the district to ensure common stingrays have a healthy environment for their summer migrations to our waters.
By guest author, Sol Lucas, Senior Conservation and Research Officer, Sussex Inshore Fisheries and Conservation Authority (IFCA)