The Wadden Sea - Ocean Biodiversity Information System

The Wadden Sea

Statistics

Occurrence records	1,336,588
Species level	1,228,739
Species	1,422
Taxa	2,656
Datasets	120
Time range	1776 - 2024

Data quality

Dropped records

Dropped records	0
Not marine	1,492
No WoRMS match	2,945
No coordinates	0
Zero coordinates	0

Taxonomic issues

Marine unsure	15,301
No accepted name available	38,261

Missing and invalid fields

Field	Missing	Invalid
coordinateUncertaintyInMeters	275,350	10,347
eventDate	1,326	0
maximumDepthInMeters	1,275,404	0
minimumDepthInMeters	1,285,134	0
occurrenceStatus	45,936	0
scientificName	4	0
scientificNameID	2,531	520

Spatial issues

Records on land	145,459
More than 20 km from shore	0
Depth exceeds bathymetric depth	1

Top datasets

Dataset	Records
O_VLIELAND - Eurasian oystercatchers (Haematopus ostralegus, Haematopodidae) breeding and wintering on Vlieland (the Netherlands) Published 2024-09-04	447,462
Royal Netherlands Institute for Sea Research (NIOZ) - Kom Fyke Mokbaai Published 2025-03-20	273,002
O_SCHIERMONNIKOOG - Eurasian oystercatchers (Haematopus ostralegus, Haematopodidae) breeding on Schiermonnikoog (the Netherlands) Published 2024-09-04	156,147
European Seabirds At Sea (ESAS) Published 2025-03-20	100,234
O_BALGZAND - Eurasian oystercatchers (Haematopus ostralegus, Haematopodidae) wintering on Balgzand (the Netherlands) Published 2024-09-04	78,863
MICROBIS Database (version 1) - European data Published	45,431
Dutch long term monitoring of phytoplankton in the Dutch Continental Economical Zone of the North Sea (2000-2018) Published 2025-03-20	37,519
O_AMELAND - Eurasian oystercatchers (Haematopus ostralegus, Haematopodidae) breeding on Ameland (the Netherlands) Published 2024-09-04	32,611
ICES Phytoplankton Community dataset Published 2025-03-20	27,779
Dutch long term monitoring of phytoplankton in the Dutch Continental Economical Zone of the North Sea Published 2025-03-20	22,481

Distribution

Disclaimer: EEZ boundaries based on Marine Regions (no endorsement).

Records

Composition

detailed (class) simple

Top taxa

Unique species IUCN Red List All taxa Unique species IUCN Red List All taxa Unique species IUCN Red List All taxa

Scientific name	Records
Haematopus ostralegus Linnaeus, 1758 NT Phylum Chordata > Class Aves	717,386
Platichthys flesus (Linnaeus, 1758) Phylum Chordata > Class Teleostei	40,384
Pleuronectes platessa Linnaeus, 1758 Phylum Chordata > Class Teleostei	28,107
Clupea harengus Linnaeus, 1758 Phylum Chordata > Class Teleostei	25,032
Larus argentatus Pontoppidan, 1763 Phylum Chordata > Class Aves	20,122
Larus fuscus Linnaeus, 1758 Phylum Chordata > Class Aves	16,458
Alosa fallax (Lacepède, 1803) Phylum Chordata > Class Teleostei	16,017
Larus ridibundus Linnaeus, 1766 Phylum Chordata > Class Aves	14,225
Larus canus Linnaeus, 1758 Phylum Chordata > Class Aves	13,990
Belone belone (Linnaeus, 1760) Phylum Chordata > Class Teleostei	12,893

Newest species

Scientific name	Records	Since
Conopeum reticulum (Linnaeus, 1767) Phylum Bryozoa > Class Gymnolaemata	10	2022
Laomedea angulata Hincks, 1861 Phylum Cnidaria > Class Hydrozoa	14	2022
Obelia dichotoma (Linnaeus, 1758) Phylum Cnidaria > Class Hydrozoa	8	2022
Myrionema balticum (Reinke) Foslie, 1894 Phylum Ochrophyta > Class Phaeophyceae	16	2022
Scardinius erythrophthalmus (Linnaeus, 1758) Phylum Chordata > Class Teleostei	12	2022
Mulinia lateralis (Say, 1822) Phylum Mollusca > Class Bivalvia	155	2022
Alcyonidium verrilli Osburn, 1912 Phylum Bryozoa > Class Gymnolaemata	9	2022
Bathycoccus prasinos Eikrem & Throndsen, 1990 Phylum Chlorophyta > Class Mamiellophyceae	24	2022
Lithodesmioides polymorpha Stosch, 1987 Phylum Heterokontophyta > Class Bacillariophyceae	29	2022
Nusuttodinium poecilochroum (J.Larsen) Y.Takano & T.Horiguchi, 2014 Phylum Myzozoa > Class Dinophyceae	13	2022

Data providers

Name	Records
Vlaamse Overheid - Instituut voor Natuur- en Bosonderzoek	717,338
University of Amsterdam, Faculty of Science, Institute for Biodiversity and Ecosystem Dynamics	716,928
Royal Netherlands Institute for Sea Research (NIOZ)	716,786
James Cook University, Townsville	447,462
Radboud University	447,462
Swedish University of Agricultural Sciences	447,462
Van Hall Larenstein University of Applied Sciences	447,462
Koninklijk Nederlands Instituut voor Onderzoek der Zee	273,137
Global Biodiversity Information Facility; Netherlands Biodiversity Information Facility	273,002
Vlaams Instituut voor de Zee	187,601