Jellyfish in Hong Kong: a citizen science dataset

Latest version published by GigaScience Press on 19 February 2024 GigaScience Press
Publication date:
19 February 2024
Published by:
GigaScience Press
CC-BY 4.0

Download the latest version of this resource data as a Darwin Core Archive (DwC-A) or the resource metadata as EML or RTF:

Data as a DwC-A file download 1,021 records in English (70 KB) - Update frequency: annually
Metadata as an EML file download in English (19 KB)
Metadata as an RTF file download in English (17 KB)


The citizen science initiative Hong Kong Jellyfish Project was started in early 2021 to enhance understanding of jellyfish in Hong Kong. Here we describe a dataset of jellyfish sightings collected by citizen scientists from 2021 through 2023 within local waters. Citizen scientists submitted photographs and simple data (time, date, location) through a website, iNaturalist project, and social media. Sightings were validated using references from the literature. A total of 987 usable observations are contained within this dataset, showing the occurrence and distribution of jellyfish in Hong Kong in 2021-2023. This dataset is now publicly available and discoverable in the Global Biodiversity Information Facility (GBIF) database and is available for download. This data can be used to enhance our understanding of the biodiversity of local marine ecosystems.

Data Records

The data in this occurrence resource has been published as a Darwin Core Archive (DwC-A), which is a standardized format for sharing biodiversity data as a set of one or more data tables. The core data table contains 1,021 records.

This IPT archives the data and thus serves as the data repository. The data and resource metadata are available for download in the downloads section. The versions table lists other versions of the resource that have been made publicly available and allows tracking changes made to the resource over time.


The table below shows only published versions of the resource that are publicly accessible.

How to cite

Researchers should cite this work as follows:

Terenzini J, Fan Y, Liu M J, Falkenberg L J (2024): Jellyfish in Hong Kong: a citizen science dataset. v1.0. GigaScience Press. Dataset/Occurrence. https://ipt.taibif.tw/resource?r=hk-jellyfish&v=1.0


Researchers should respect the following rights statement:

The publisher and rights holder of this work is GigaScience Press. This work is licensed under a Creative Commons Attribution (CC-BY) 4.0 License.

GBIF Registration

This resource has been registered with GBIF, and assigned the following GBIF UUID: e85c3b78-b780-4955-a50b-4adf2830a07c.  GigaScience Press publishes this resource, and is itself registered in GBIF as a data publisher endorsed by Participant Node Managers Committee.


Occurrence; jellyfish; Cnidaria; Hong Kong; China; scyphomedusae; hydromedusae; ctenophora; cubozoa; siphonophora


Yannan Fan
  • Originator
Gigascience Press, BGI Center
BGI Center, Meisha Street, Yantian district
518000 Shenzhen
Laura J Falkenberg
  • Originator
Academic Advisor
UniSA STEM, University of South Australia
Melissa Jean-Yi Liu
  • Metadata Provider
  • Originator
Content Manager
Taiwan Biodiversity Information Facility, TaiBIF
C301, No. 28, Ln 70, Sec 2 Academia Rd.
11574 Taipei City
Nangang Dist.
John Terenzini
  • Originator
  • Point Of Contact
Hong Kong Jellyfish Project
Hong Kong

Geographic Coverage

Waters around Hong Kong Special Administrative Region

Bounding Coordinates South West [22.1, 113.57], North East [22.58, 114.54]

Taxonomic Coverage

Jellyfish as defined in Brotz et al. (2012) as "gelatinous zooplankton that include medusae of the phylum Cnidaria (scyphomedusae, hydromedusae, cubomedusae, and siphonophores) and planktonic members of the phylum Ctenophora." All observations were identified to the lowest taxonomic level possible, typically genus or species level.

Phylum Cnidaria, Ctenophora

Temporal Coverage

Start Date 2021-01-03

Project Data

The Hong Kong Jellyfish Project (HKJP) is a citizen science initiative seeking more information about jellyfish presence, abundance, and distribution in Hong Kong waters. Citizen science involves members of the public contributing their time and efforts to advance scientific knowledge in collaboration with scientists. The HKJP uses a website, iNaturalist project, and social media to collect observations of local jellyfish. This data is used to fill the research gap into local jellyfish due to out-of-date records.

Title Hong Kong Jellyfish Project
Identifier https://www.hkjellyfish.com/
Funding Not applicable
Study Area Description Hong Kong Special Administrative Region (SAR) is located on the southern coast of mainland China at 22.3193° N, 114.1694° E, at the northern end of the South China Sea. Its marine boundary contains 1,651 km² of water and a rich marine biodiversity despite being only 0.03% of Chinese waters. The location of Hong Kong in the South China Sea means there is overlap of tropical and temperate climate species and, due to Hong Kong’s status as a major maritime port with highly disturbed shorelines, there is also high potential for invasive marine species to be present. The biodiversity of Hong Kong is extensively studied however gaps remain in the publicly available records, particularly in terms of species records and how they are changing over time, with potential for previously unrecorded species to be found. All jellyfish observations from the HKJP were made in Hong Kong waters.
Design Description The Hong Kong Jellyfish Project (HKJP) uses citizen science methodology to investigate the presence, abundance, and distribution of jellyfish in Hong Kong. The HKJP uses a website, iNaturalist project, and social media to collect observations of jellyfish from Hong Kong waters. This project seeks to fill the research gap for local jellyfish due to out-of-date records. Observations are collected, jellyfish identified with reference to the literature, and records collated to provide a clearer picture of the presence, seasonality, and distribution of local jellyfish.

The personnel involved in the project:

John Terenzini

Sampling Methods

Participants submit any observation of an individual jellyfish or group of jellyfish, or multiple observations of different jellyfish at their own discretion. Additionally, observations of the absence of jellyfish can be reported through the HKJP website or social media, and these can be captured in GBIF. Jellyfish are encountered opportunistically by participants as they conduct normal daily activities. Observations typically increase during high bloom times in April and May following a seasonal pattern. Sightings are also reported following project promotion through social (Facebook, Instagram) or traditional media (radio, newspaper). Periodic HKJP newsletters by email and journal posts on iNaturalist are conducted to maintain observer interest and promote project awareness. Each observation from the HKJP website includes fields describing their: (i) taxonomy to the lowest level possible (kingdom, phylum, class, order, family, genus, species); (ii) location in observer’s own words or geolocation (latitude, longitude); (iii) date of observation (dd/mm/yyyy); (iv) time of observation (24hr); (v) how many jellyfish were seen (No jellyfish seen, 1, <10, 10-100, 100-500, 500-1000, not recorded/don’t know); (vi) space between individuals (10cm, <1m, 1-5m, 5-10m, 10-20m, >20m, not recorded/don’t know); (vii) individuals per square meter (<10, 10-100, 100-500, >500, not recorded/don’t know); (viii) observation made while (fishing, sailing, diving/snorkeling/swimming, on a boat/ferry, walking along the coast, kayaking/SUP, other); (ix) photograph(s) and/or video of jellyfish. For observations that came through social media we attempted to obtain as much of the above information as possible, though greater gaps remain in this dataset. Observations from the iNaturalist project include fields describing: (i) user id; (ii) date of observation (dd/mm/yyyy); (iii) time of observation (24hr); (iv) URL of observation; (v) image URL; (vi) place guess; (vii) latitude of the observation; (viii) longitude of the observation; (ix) species guess; (x) the scientific name to the lowest level possible (kingdom, phylum, class, order, family, genus, species); (xi) the common name as determined by iNaturalist. The observations data has been compiled into the Darwin Core format with fields including: (i) occurrenceID (ii) basisOfRecord (iii) type (iv) language (v) institutionID (vi) institutionCode (vii) recordedBy (viii) eventDate (ix) eventTime (x) associatedReferences (xi) associatedMedia (xii) type (xiii) locality (xiv) decimalLatitude (xv) decimalLongitude (xvi) geodeticDatum (xvii) country (xviii) stateProvince (xix) vernacularName (xx) scientificName (xxi) acceptedNameUsageID (xxii) taxonRank (xxiii) kingdom.

Study Extent Hong Kong Special Administrative Region (SAR) is located on the southern coast of mainland China at 22.3193° N, 114.1694° E, at the northern end of the South China Sea. Its marine boundary contains 1,651 km² of water and a rich marine biodiversity despite being only 0.03% of Chinese waters. This study has been running since early 2021 and is a continuous year-round collection of observations of jellyfish.
Quality Control Observations that did not contain verifiable photographs, non-medusa taxa, or were taken from captivity were eliminated from the dataset. Usable observations were identified to the lowest taxonomic level and verified with reference to the literature; primarily, the World Atlas of Jellyfish (2019), Mayer (1910), Kramp (1961), and other sources as required. Some observations were verified by sampling and DNA analysis done at the Simon F.S. Li Laboratory at The Chinese University of Hong Kong. The dataset is made available in Darwin Core format; 987 terms are available for the 2021-2023 datasets. All mandatory fields are present and have undergone validation and screening using the TaiBIF IPT, before uploading and publishing via the GigaScience Press GBIF page.

Method step description:

  1. 1) A citizen scientist observes jellyfish (or absence of jellyfish) while swimming, kayaking, or walking the shore, for example. 2) The observer takes a photograph of the jellyfish and uploads it either through the HKJP website or the iNaturalist app on their phone. They note the date, time, location, and species, if known. Additional information like number and density of jellyfish may be optionally provided if there is a large number of them present. 3) For a submission reported through the website, it is reviewed by the HKJP principal investigator for identification verification and if necessary, reference is made to the literature. Confirmation and additional species information is then shared with the observer. If an observation is unable to be identified it is included in the dataset, but the lack of identification is clearly indicated. 4) For a submission reported through iNaturalist, artificial intelligence usually suggests an identification or a category after automatically recording location and time data within the observer’s pre-set parameters. The observer can select the suggested identification or make their own. Anyone on iNaturalist can suggest an identification and when multiple people agree, the identification is considered Research Grade. 5) For a submission reported on social media, the HKJP principal investigator will ask for as much information (time, date, location, etc.) as possible about the observed jellyfish and permission for use. 6) Observation data for all three sources is recorded into an Excel spreadsheet. Website and iNaturalist submissions can be entered in Traditional Chinese, so observations are translated to English for inclusion in the spreadsheet, the language of the HKJP’s principal investigator. 7) The various data sources are harmonized and curated together into one table, which is then converted into Darwin Core Archive standard to be uploaded to GBIF.

Additional Metadata

Earlier portions of this dataset supported the publication: Terenzini, J., Li, Y., & Falkenberg, L. J. (2023). Unlocking Hong Kong’s hidden jellyfish diversity with citizen science. Regional Studies in Marine Science, 62, 102896. https://doi.org/10.1016/j.rsma.2023.102896

Purpose This dataset was created to summarize jellyfish observations sent to the Hong Kong Jellyfish Project in Hong Kong between 2021-2023. This dataset supports jellyfish research in Hong Kong and provides a foundation for further research.
Maintenance Description Updates to this dataset will be made annually.
Alternative Identifiers https://ipt.taibif.tw/resource?r=hk-jellyfish