https://www.dassh.ac.uk/ipt/resource?r=st_greateggcasehunt ST_GEH Harriet Allen Shark Trust Data Analyst

4 Creykes Court, 5 Craigie Drive Plymouth Devon pl13jb GB

conservation@sharktrust.org Harriet@sharktrust.org 0000-0001-5108-2032 Cat Gordon Shark Trust Senior Conservation Officer

4 Creykes Court, 5 Craigie Drive Plymouth Devon pl13jb GB

cat@sharktrust.org Harriet Allen Shark Trust Data Analyst

4 Creykes Court, 5 Craigie Drive Plymouth Devon pl13jb GB

conservation@sharktrust.org Harriet@sharktrust.org 0000-0001-5108-2032 2026-04-30 eng This dataset details approved records from the Shark Trust's Great Eggcase Hunt, active since 2003. Comprised of citizen science observations, both on land and in-situ, records of eggcases from around the world have been complied to help better understand these oviparous species. Data comes from ad-hoc records, regular surveys and data uploads from partner organisations. Please note that not all records are verified, but this has been indicated in the extended Measurements or Facts. Samplingevent GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type_2015-07-10.xml oviparity Egg Aquatic Sciences and Fisheries Thesaurus social participation Chondrichthyes CABI Thesaurus Observation GBIF Dataset Subtype Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_subtype.xml This work is licensed under a Creative Commons Attribution (CC-BY 4.0) License. Creative Commons Attribution 4.0 International https://spdx.org/licenses/CC-BY-4.0.html CC-BY-4.0 http://www.eggcase.org Global, with a participation bias from the British Isles. -180 180 90 -90 2003-01-01 2024-12-31 Chondrichthyes, specifically Heterodontidae, Orectolobidae, Rajidae, Scyliorhinidae and Chimaeriformes class Chondrichthyes family Heterodontidae bullhead sharks family Orectolobidae carpet shark family Rajidae skate family Scyliorhinidae catsharks order Chimaeriformes chimaeras This dataset displays the broad distribution, diversity of species, and relative abundance of sharks, skates and chimaera around the British Isles and further afield. The Shark Trust’s Great Eggcase Hunt engages communities in searching for, identifying, and recording the eggcases of sharks, skates and chimaera. This feeds a better understanding of these species, and which areas provide important habitats like egglaying grounds. Some citizen scientists regularly submit finds from their local beaches, while others may make a new shoreline discovery that leads them to discover what a mermaid’s purse really is. With over half a million eggcases recorded by the public over 20+ years, this dataset displays the broad distribution, diversity of species, and relative abundance of sharks, skates and chimaera around the British Isles and further afield. This data allows for an improved understanding of this important development stage of a sharks or skates life-cycle. This data is comprised of three tables: Event, Occurrence and extended measurements or facts. The field 'search effort' details the number of participants taking part in the survey as a measure of effort. However, this field has only been in use since 2022. The field 'locationRemarks' details whether the eggcase was seen developing in-situ underwater, or it was recorded on-shore - likely a spent eggcase. While every record is checked by a member of staff or through the Community Verification Platform, 'identificationVerificationStatus' flags whether the record had any evidence to prove the species ID. Accepted evidence types  include a photograph, specimen or expert ID. This dataset would not be possible without the contributions of all citizen scientists and organisations that have participated. Whether reporting one ad-hoc find or thousands of records over the span of years, every record has helped build towards this combined dataset.Data transformation and publication was funded by the European Union under the Horizon Europe Programme with Grant Agreement No. 101112823 (DTO-BioFlow) through an FSTP call. Each subsequent year of data will be uploaded once internal QC has been completed. annually Harriet Allen Shark Trust Data Analyst

4 Creykes Court, 5 Craigie Drive Plymouth Devon pl13jb GB

conservation@sharktrust.org Harriet@sharktrust.org 0000-0001-5108-2032 Cat Gordon Shark Trust Senior Conservation Officer

4 Creykes Court, 5 Craigie Drive Plymouth Devon pl13jb GB

cat@sharktrust.org NA Data is generated from citizen science observations. Many are ad-hoc finds, while some areas are more regularly surveyed using a standardised methodology. The majority of finds are from beach records, with some being in situ records observed while snorkelling or diving. Records are gathered from citizen science observations submitted on an ad-hoc basis, with some Eggcase Champions and partner organisations undertaking more regular, structured surveys. All data has been approved by a member of staff or via a user of the Community Verification Platform before publication. All records have undergone internal Quality Checks, with checks made against known species range and pin location checked and adjusted as required. Harriet Allen 0000-0001-5108-2032 owner Cat Gordon owner The Shark Trust’s Great Eggcase Hunt engages communities in searching for, identifying, and recording the eggcases of sharks, skates and chimaera. This feeds a better understanding of these species, and which areas provide important habitats like egglaying grounds. Some citizen scientists regularly submit finds from their local beaches, while others may make a new shoreline discovery that leads them to discover what a mermaid’s purse really is. With over half a million eggcases recorded by the public over 20+ years, this dataset displays the broad distribution, diversity of species, and relative abundance of sharks, skates and chimaera around the British Isles and further afield. This data allows for an improved understanding of this important development stage of a sharks or skates life-cycle. Historic funders include: Co-op, Countryside Council for Wales, Crown Estates, DTO Bio-Flow, Esmée Fairbairn Foundation, Museums and Galleries of Wales, National Lottery Heritage Fund, Natural England, Save Our Seas Foundation, Scottish Natural Heritage, Sea Changers and donations received through specific Shark Trust appeals. Global, with a participation bias from the British Isles. Eggcases can be recorded from anywhere around the world, whether recorded in-situ, or washed ashore on the beach, in the sand dunes or the car-park. Records are submitted on an ad-hoc basis, with some Eggcase Champions and partner organisations undertaking more regular, structured surveys. 2026-03-30T16:52:28.347+01:00 dataset Allen H, Gordon C (2026). Great Eggcase Hunt - global citizen science observations of chondrichthyian eggcases. Version 1.2. Shark Trust. Samplingevent dataset. https://www.dassh.ac.uk/ipt/resource?r=st_greateggcasehunt&v=1.2 https://www.dassh.ac.uk/ipt/logo.do?r=st_greateggcasehunt https://www.dassh.ac.uk/ipt/resource?id=st_greateggcasehunt/v1.2.xml