A new partnership between the Shark Trust and BSAC is calling on divers to help identify where sharks and skates lay their eggs—an often hidden stage of their life cycle.
Diver and egg case
The Shark Trust has launched a collaboration with the British Sub-Aqua Club (BSAC), encouraging divers and snorkellers to contribute to ongoing citizen science initiatives aimed at improving knowledge of egg-laying shark and skate species.
Central to the effort is the long-running Great Eggcase Hunt, which invites participants to record so-called “mermaid’s purses”—the eggcases of sharks and skates—found on beaches and underwater. While more than 600,000 eggcases have been logged over the past two decades, fewer than one percent of records come from underwater observations.
This is where divers can play a crucial role.
Eggcases seen attached to seabed habitats or seaweed—often containing developing embryos—provide valuable insight into breeding areas that cannot be identified from washed-up cases alone. Linking these habitats to shoreline findings could help scientists better understand and protect key nursery grounds.
The partnership will also support the Great Shark Snapshot in July 2026, encouraging divers worldwide to log sightings of sharks, skates and rays.
Organisers say the initiative highlights how divers can contribute directly to marine conservation by recording what they encounter beneath the surface.
Eggcases seen developing underwater are a crucial piece of the puzzle. They help us link the areas where empty eggcases regularly wash ashore with the habitats that are important for this stage of the life cycle. We’re asking divers and snorkellers to keep an eye out for eggcases seen attached to seaweed or seabed habitats.
Cat Gordon, Senior Conservation Officer
