Hunt for shark eggs this easter
A White Skate eggcase (Rostroraja alba — Critically Endangered) This one is more than 15cm long. Picture: Louise Overy
It's not a belated April Fool's joke — some shark and skate species do indeed lay eggs.
Ireland has an amazing diversity of marine species including the group called Elasmobranchs which are more commonly known as sharks, skates and rays. Many of these give birth to live young but others lay eggs.
These egg cases are often known as mermaid's purses due to their shape and each egg case is unique to the species that laid it.
Similar to a chicken egg, each egg case houses a single embryo which after a long incubation period will eventually hatch a perfect miniature shark or skate. The incubation period for these egg cases can vary anywhere from 6-15 months.
Unlike a chicken egg, these eggs are made of a protein called collagen. This gives them a leathery pouch-like appearance which can easily be mistaken for dried seaweed when the empty cases wash up on our shores.
And unlike humans, these little baby skates and sharks are on their own in the world from the moment they are laid
Finding and recording these eggcases can really help marine scientists — and as each species lays a distinctive eggcase you can even find out which species each egg case is from.
Check out the Irish Elasmobranch Group social media pages for details of egg hunts around the coast.
If you would prefer to do an egg case hunt in your own time and on your own beach, then you can find more information and an identification guide at Purse Search Ireland.
Or you can use ' Great Eggcase Hunt' — the free Shark Trust mobile phone app.
The Irish marine territory is a vast 220 million acres, which makes the Irish marine territory 10 times the size of Ireland’s land mass. Sharks, skates, and rays play an important role in keeping the ocean ecosystems balanced, healthy and productive. And in Irish waters there have been an impressive 39 species of shark and 33 species of skates and rays recorded here to date.
These all come in an amazing variety of shapes and sizes from the world’s fastest shark, the Short-fin Mako, to the magnificent and second-largest shark in the world, the Basking shark, to the relatively unheard-of, but Critically Endangered species, the Angel Shark.
And it is this last species that marine biologists are currently looking for your help with.
Unknown by many and often referred to as Monkfish, the Angelshark is a species of flat shark that lives on the seabed and buries itself under the sand to ambush its prey, including small fish, crustaceans, and molluscs.
This species has been listed as Critically Endangered across its range by the IUCN and the elasmobranch group (sharks, skate, and rays) as a whole are the second most threatened group of vertebrates worldwide.
The Angelshark is under pressure all across its range largely from bottom fisheries due to its benthic (bottom dwelling) lifestyle, and this is compounded by their slow reproductive rate. These factors mean that this species is very sensitive to increased pressures on their population or habitat and in the past few decades there has been a shocking decline of this most amazing species.
There is still much we don’t know about the Angelshark such as where it lives in Irish waters and what factors are key to its recovery. The overall aim of the Irish Elasmobranch Group's newly launched Angelshark Project: Ireland (https://angelsharkproject.com/) is to fill these gaps in our knowledge and to find ways to safeguard them for future generations. The team hopes to better understand the species’ ecology with the help and support of the local communities and fishers and the huge amount of knowledge they have gained. If you have ever encountered an Angelshark then the team wants to hear from you at angelsharksireland@gmail.com
The work here in Ireland will be led by the Irish Elasmobranch Group (IEG) and it will work to support the work by the other Angelshark projects across their range including Corsica, Croatia, Libya, Greece, the Canary Islands, and Wales.
Partners and collaborators include Inland Fisheries Ireland, University College Dublin Veterinary Hospital, Sea Fisheries Protection Authority, National Parks and Wildlife Trust, Natural Resources Wales, Zoological Society of London, Leibniz Institute for the Analysis of Biodiversity Change and Universidad de Las Palmas de Gran Canaria and the project funder, the Shark Conservation Fund.
