Become a citizen scientist and help us learn more about sharks, skates and rays by finding and recording eggcases

We'll take you through everything you need to know for how to search for, identify, and record your eggcase finds, just click through on the buttons below.

Eggcase hunting is great fun for all ages! It also gets a little bit competitive and is certainly addictive!

Download the new Shark Trust App here:

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Some sharks, and all true skates, reproduce by laying eggs. These are surrounded by a tough leathery capsule that protects the embryo as it develops inside. After several months these are ready to hatch, and a fully-formed shark or skate will emerge. Please note that in the UK many skate species are referred to as rays in their common names.

Once empty, the eggcases (or mermaid’s purses) often wash up on the beach. One of the best places to find them is among the strandline, where the seaweed washes up. The eggcases of different species vary. So, by looking at the size, shape and features, we can tell which species laid it. You can learn to identify eggcases too. We’ll show you how!

Skate Life-cycle Poster

Cat Shark Life-cycle


The Great Eggcase Hunt began in 2003 following a chance find on a beach in Devon. The project quickly developed with the aim of getting as many people as possible out hunting for eggcases and recording their finds.

Empty eggcases can help indicate species presence and diversity. By recording your finds, you're helping us to discover more about egglaying species in our waters.

Eggcases wash up all year round. So, whatever the time of year keep your eyes peeled!

Great Eggcase Hunt 20 Year Report


As well as documenting empty eggcases, we're keen to receive records of eggcases developing in-situ.

Underwater records help us pin-point exactly where sharks and skates are laying and can be linked to beach records. Learning the depth and substrate that they lay on also helps us to better understand the species.

So, if you're a diver, snorkeller, stand-up paddleboarder, or anyone who enjoys spending time in the water, keep an eye out. Often they're extremely well camouflaged and can have marine organisms such as algae growing on them. If you do spot one make a note of the location and, if possible, take a photo. Then record your finding as normal.

Remember - these eggs may contain a live shark or skate, so it's important not to disturb them.


Eggcase hunting has taken off in a big way! What began as a British project has now expanded around the world. We’ve got records from Ecuador to South Africa to Australia, and many places in between. In total, we've had 49 species reported from 30 countries!

We've also developed the project in other regions, in collaboration with the following partners:

  • Grote Eikapsel Jacht in partnership with the Dutch Shark Society (launched in April 2015).
  • Grande Caça Ovos in partnership with the Portuguese Association for the Study and Conservation of Elasmobranchs (APECE).
  • Great Eggcase Hunt Australia in partnership with The Commonwealth Scientific and Industrial Research Organisation (CSIRO) launched in 2023. Click here to see the project page.

As well as ID guides with our above partners, we have developed translated and/or regional eggcase ID guides in collaboration with many other partners around the world. You can see our ID guides here.

  • Project SIARC (Wales - Welsh) ID Guide

  • Sanamares, Lamna and Submon (Spain - Spanish) ID Guide

  • Mersea Consulting (Türkiye - Turkish) ID Guide

  • iSea (Greece - Greek) ID Guide

  • Marine Biology in Libya (Libya – Arabic and English) ID Guide

  • ASCOB-Syrtis (Tunisa – Arabic and English) ID Guide

  • North Carolina Aquariums (North Carolina, USA – English) ID Guide

Sister projects to the Great Eggcase Hunt have been set up in other regions:

  • Programme CapOeRa by APECS (France)
  • Purse Search by Marine Dimensions (Ireland)
  • South African Elasmobranch Monitoring - ELMO (South Africa)

Within the UK, we collaborate with other organisations to promote eggcase hunting as a way to engage with shark conservation and we share eggcase data:

  • Orkney Skate Trust collect data on the Flapper Skate in and around Orkney and North Scotland.
  • Shetland Community Wildlife Group encourage local people to get involved in nature whilst learning new skills and collecting natural history records.
  • Project SIARC (working with North Wales Wildlife Trust, ZSL and Natural Resources Wales) seeks to safeguard elasmobranchs in Wales and use eggcase hunts as a way to engage people in citizen science.
  • Sea Deep project (Ulster Wildlife Trust) champions elasmobranchs in the waters around Northern Ireland.
  • Wild Coast Sussex (led by Sussex Wildlife Trust) helps connect Sussex communities to the ocean and uses the Great Eggcase Hunt to educate people about sharks, skates and rays.


Thank you to everyone who has taken part in the Great Eggcase Hunt!

Together we’ve recorded over 375,000+ individual eggcases - that's a lot of eggcases! The database is continuing to grow, with more and more records being submitted, including many from around the world.

Eggcase Surveys (2003-present day)

We need to see photos or specimens for us to publish records as verified. Those we haven’t seen are considered unverified and these records may not be accurate.

► Click here to view interactive maps on our Recording Hub (This page is currently undergoing an update and will be available again soon)

Student Projects - If you’d like to use any of these results for a student project, please contact us first. Provide us with a summary of your project and the information you'd like to use but please be aware we're not able to release the entire raw dataset.

Is your home beach or favourite stretch of coastline covered? If not, why not get involved? Eggcase hunting is a great way of finding out what sharks and skates live off your stretch of coastline.

Related Links

Photo Credits

Banner: James Harris

Underwater Eggcases: Linda Pitkin