Research Ideas and Outcomes : Project Report
Corresponding author: Vasilis Gerovasileiou (email@example.com)
Received: 09 Sep 2016 | Published: 13 Sep 2016
© 2016 Vasilis Gerovasileiou, Alejandro Martínez, Fernando Álvarez, Geoff Boxshall, William F. Humphreys, Damià Jaume, Leontine E. Becking, Guilherme Muricy, Peter J. van Hengstum, Stefanie Dekeyzer, Wim Decock, Bart Vanhoorne, Leen Vandepitte, Nicolas Bailly, Thomas M. Iliffe.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Gerovasileiou V, Martínez A, Álvarez F, Boxshall G, Humphreys W, Jaume D, Becking L, Muricy G, van Hengstum P, Dekeyzer S, Decock W, Vanhoorne B, Vandepitte L, Bailly N, Iliffe T (2016) World Register of marine Cave Species (WoRCS): a new Thematic Species Database for marine and anchialine cave biodiversity. Research Ideas and Outcomes 2: e10451. doi: 10.3897/rio.2.e10451
Scientific exploration of marine cave environments and anchialine ecosystems over recent decades has led to outstanding discoveries of novel taxa, increasing our knowledge of biodiversity. However, biological research on underwater caves has taken place only in a few areas of the world and relevant information remains fragmented in isolated publications and databases. This fragmentation makes assessing the conservation status of marine cave species especially problematic, and this issue should be addressed urgently given the stresses resulting from planned and rampant development in the coastal zone worldwide. The goal of the World Register of marine Cave Species (WoRCS) initiative is to create a comprehensive taxonomic and ecological database of known species from marine caves and anchialine systems worldwide and to present this as a Thematic Species Database (TSD) of the World Register of marine Species (WoRMS). WoRCS will incorporate ecological data (e.g., type of environment, salinity regimes, and cave zone) as well as geographical information on the distribution of species in cave and anchialine environments. Biodiversity data will be progressively assembled from individual database sources at regional, national or local levels, as well as from literature sources (estimate: >20,000 existing records of cave-dwelling species scattered in several databases). Information will be organized in the WoRCS database following a standard glossary based on existing terminology. Cave-related information will be managed by the WoRCS thematic editors with all data dynamically linked to WoRMS and its team of taxonomic editors. In order to mobilize data into global biogeographic databases, a Gazetteer of the Marine and Anchialine Caves of the World will be established. The presence records of species could be eventually georeferenced for submission to the Ocean Biogeographic Information System (OBIS) and constitute an important dataset for biogeographical and climate change studies on marine caves and anchialine systems.
Marine caves, anchialine ecosystems, biodiversity, global species databases, biodiversity management
Scientific exploration of underwater cave environments over recent decades has led to outstanding discoveries of novel taxa, increasing our knowledge on biodiversity. Marine and anchialine caves are widely acknowledged as biodiversity reservoirs (
Marine and anchialine caves represent extreme environments due to their lack of light, paucity of organic nutrients, and often low levels of dissolved oxygen (
The proposal for launching a World Register of marine Cave Species (WoRCS) originated from a question raised by V. Gerovasileiou who has conducted research in marine caves to N. Bailly as a taxonomic editor in WoRMS (for fishes) while they both worked for LifeWatchGreece Research Infrastructure in the Hellenic Centre for Marine Research (HCMR). The proposal was presented to the World Register of Marine Species (WoRMS) Steering Committee (SC) during its meeting at HCMR in Crete (8th June 2015). The SC agreed in principle to support this initiative. A proposal submitted to the LifeWatch Belgium grant mechanism for organizing WoRMS editor workshops was accepted in October 2015. A pre-workshop meeting was attended by five of the eight WoRCS founding editors during the Third International Symposium on Anchialine Ecosystems hosted by the Universidad Autónoma de Yucatán (UADY), Mérida, México, in November 2015. The aim of the meeting was to refine the agenda and plan preparatory work for the Editor Workshop.
The first Editor Workshop of the WoRCS was held from 22 to 25 February 2016, at the Flanders Marine Institute (Vlaams Instituut voor de Zee) (VLIZ), Oostende, Belgium.
The World Register of marine Cave Species (WoRCS) aims to create a comprehensive taxonomic and ecological database of species known from marine caves and anchialine environments worldwide. The assembled data will form a Thematic Species Database (TSD) of WoRMS (
2.2. Ecological scope: types of environments
There have been extensive discussions among specialists in order to characterize the different types of caves comprising anchialine ecosystems. Although a consensual definition was published (
2.3. Taxonomic scope
The taxonomic scope of WoRCS covers primarily Protozoa and Animalia. Data entry on other kingdoms (e.g. Bacteria, Chromista, and Plantae) may be considered upon an opportunistic basis (e.g., for bacterial mats). Data associated with taxa at supra-species ranks will not be added to WoRCS until there is good evidence for the possible species identification. However, these data may be valuable, and a mechanism specific to WoRCS will be elaborated, e.g., through data files uploaded in the Integrated Marine Information System (IMIS) as sources.
2.4. Occurrence status scope
During the 1st Editor Workshop of the WoRCS there was a discussion if all epigean accidental visitors should be included in the taxonomic scope, especially in anchialine caves that are connected to freshwater systems where the water flow alone could be responsible for such occurrences (e.g., for cadavers) but also for accidental visitors reported from the entrance zone of submarine caves. This may significantly increase the number of species to document in WoRCS, beyond the Editorial Team capacities. The same responsible expertise approach as exposed in the subsection "2.2. Ecological scope: types of caves" above will be used; it could be also summarized like: keep the focus on data that are ecologically significant. The weakness of this approach is that rarely reported species could be eliminated while in the opposite case, with the potential accumulation of occurrence reports, we could extract some ecological signal. On the other hand, it was decided that only published information will be used (see Section 3 below), and literature sources summarizing these rare reports will be recorded in WoRCS.
2.5. Geographic scope
WoRCS aims at including data from all around the world. The discussions during the 1st Editor Workshop highlighted the difference of scientific research efforts in the various regions of the world. One consequence might be the apparent incompleteness of WoRCS, related to research effort bias. WoRCS has a role to promote research in understudied regions and will conduct a progressive geographic gap analysis.
The primary sources of information used for WoRCS are published species records, based on peer-reviewed literature sources. However, reliable unpublished records coming from offline databases, museum collections, field notes and the primary research of the WoRCS thematic editors will be also considered case by case. The WoRCS thematic editors are responsible for updating the content of the TSD by incorporating newly published records along with the new findings of their own research.
However, the main source of data in the initial upload into WoRCS was based on individual databases assembled by the WoRCS thematic editors and collaborators, as well as online global species databases, containing species lists from marine and anchialine caves and covering a broad taxonomic, geographic and temporal scale. A detailed description of the main database sources used by WoRCS is given below:
3.1. World Register of Marine Species (WoRMS)
WoRMS already included a considerable number of cave-exclusive species and ca. 850 literature sources containing the string “cave” in their title, before the creation of the WoRCS TSD. All cave-related references were automatically incorporated into WoRCS by the WoRMS Data Management Team (DMT). Furthermore, the taxonomic editors of WoRMS have the possibility to assign cave species to the WoRCS context, in collaboration with the thematic editors of WoRCS, as was the case of the mysid Heteromysis (Olivemysis) ekamako, described from a marine cave in French Polynesia by
3.2. Database of Mediterranean marine cave biodiversity
This database of Mediterranean marine cave biodiversity was created by V. Gerovasileiou and E. Voultsiadou, with technical assistance by N. Bailly. It contains >11,300 records of 2,500 taxa reported from >380 caves in 15 Mediterranean countries. Data were derived from 322 scientific studies, but also from primary research in eastern Mediterranean marine caves. Preliminary results and a short description of the database have been published by
3.3. Subterranean marine cave fauna of the World
This database has been created by A. Martínez and collaborators, including Thomas M. Iliffe, Brett C. Gonzalez, Diego Fontaneto and Katrine Worsaae, by compiling records published in the literature (e.g.,
3.4. Anchialine Caves and Cave Fauna of the World
The "Anchialine Caves and Cave Fauna of the World" website by Thomas M. Iliffe includes species lists from anchialine caves of Bahamas, Bermuda and Yucatan. The purpose of the website is to document the diversity, significance and distribution of anchialine caves and cave animals.
3.5. Database from Stygofauna Mundi
During the BioFresh project, the FishBase Information and Research Group (FIN) was charged with digitizing the crustacean part of the book by
3.6. SeaLifeBase and FishBase
The "ECOLOGY" table in the SeaLifeBase already records about 60 species from caves, mainly from South America, which is complementary to the sources cited above. Some information is also recorded for fishes in FishBase (
3.7. Aquatic cave fauna of Mexico and Central America
This database was started by Fernando Álvarez in the 1990s in the context of several projects about groundwater fauna of the Yucatan Peninsula. It is mostly dedicated to Decapoda, and it records the occurrences of 52 anchialine species and up to 25 accidental species, in 226 localities of marine and anchialine caves. It contains taxonomical information, bibliographical references, specimen collection whereabouts, and conservation areas. The current location of the database is "Unidad de Informática para la Biodiversidad" (UNIBIO), but it will change and be moved with all collections of Universidad Nacional Autónoma de México (UNAM) under the Coordinación de Colecciones Universitarias Digitales (CCUD) project.
3.8. Anchialine fauna of the Balearic Islands
The list of 89 species occurring in anchialine caves of the Balearic Islands, compiled by Damià Jaume, was stored in a spreadsheet with the taxonomy, AphiaID, habitat and remarks (
3.9. Taxonomic Catalog of the Brazilian Fauna (TCBF):
The Taxonomic Catalog of the Brazilian Fauna (
3.10. Anchialine lakes and pools in the Indo-Pacific
Anchialine lakes and pools in the Indo-Pacific have been the subject of research of several studies concerning predominantly sponges (e.g.,
A dynamic webpage (
The WoRCS webpage presents basic information about the aims, the Editorial Team, literature sources and cave species, incorporating the basic taxonomic and search tools (e.g. Taxon Tree and Taxon Search) of Aphia (
Descriptions of the content of the WoRCS database are also presented (
In addition to the taxonomic information, the WoRCS database will be progressively enriched with information on the ecology and geographical distribution of cave species. The decapod species Munidopsis polymorpha Koelbel, 1892 is presented here as an example (
The WoRCS taxon details page includes taxonomic information, references, vernacular names and distribution data, along with a series of attributes gathering information about morphology, biology, reproduction and ecology of each cave species.
Example of an image in WoRCS, showing the habitus and some aspects of the biology of a cave species.
In order to generate occurrence data to be eventually served to the Ocean Biogeographic Information System (OBIS) and the Global Biodiversity Information Facility (GBIF), the WoRCS Editor Group will establish a gazetteer for the marine caves and anchialine systems of the world that will be coordinated by T.M. Iliffe. Thus, the species records available at WoRCS will be progressively georeferenced and layers for cave occurrence mapping will be created, providing an important dataset for the biogeographical and climate change studies on these ecosystems. The cave data will be integrated in the "Cave" object types in Marine Regions. Each marine cave or anchialine system will be described with 14 specific descriptors (see section 6.4 below). These descriptors will be searchable under the WoRCS interface through various filters. From the 14 descriptors, at least two will be mandatory for each cave or access point: (i) name or code, and (ii) coordinates or a locality. The coordinates will be provided only with three decimals of precision for possible conservation, privacy, and human security issues, especially regarding amateur and touristic diving. For instance, anchialine lakes in Indonesia are often being converted into aquaculture farms or holding basins for storing caught fish (
Different mapping options, complementary to the mapping functionalities proposed by WoRMS and Marine Regions, such as enabling overlays with OBIS occurrence [see World Porifera database (
WoRCS will incorporate data on the biodiversity of marine caves and anchialine ecosystems of the world. In order to uniformly handle information within WoRCS, the editors compiled a list of targeted descriptors and a standard glossary based on existing terminology.
6.1. Species known to occur in marine cave or anchialine ecosystems of the world
6.2. Ecological categorization of the species included in WoRCS
The species included in the database will be categorized according to the following ecological descriptors:
6.2.1. Species salinity preference (multichoice)
6.2.2. Ecological categories of taxa (after
6.2.3. Light zones (after
6.2.4. Microhabitats, e.g., pools in caves, other physico-chemoclines (free text)
6.3. Geographical distribution in marine caves and anchialine systems
Species records will be georeferenced using the coordinates from the Gazetteer of marine and anchialine caves.
6.4. Type of environment
Distinction between records from freshwater, anchialine and fully marine caves involves consideration of hydrographic data, especially salinity regimes (e.g., freshwater, pycnocline, marine water).
6.4.1. Water regime (multichoice)
6.4.2. Level of water mixing (for anchialine lakes and pools)
6.4.3. Access point
6.4.4. Local terms
6.4.5. Rock type (from
6.4.6. Oxygen concentration (from
6.4.7. Cave morphology (from
6.4.8. Submersion level (multichoice)
6.4.9. Tidal amplitude (number)
6.4.10. Total length of the cave (number)
6.4.11. Maximum water depth (number)
6.4.12. Minimum water depth (number)
6.4.13. Position of the entrance from sea level (number)
6.4.14. Remarks (free text to mention exceptions, additions, or other general comments)
6.5. Other types of data
7.1. Constitution of the Editorial Team
The WoRCS Editorial Team is composed of thematic editors. Twelve of these editors will constitute the Editor Group that manages WoRCS, covering a broad taxonomic and geographical range. The WoRCS Editor Group will manage the membership in the team and in the group on consensus basis from any proposal or suggestion. No rules have been formally established for acceptance and exclusion of members. In case of difficulties, WoRCS will follow the current rules and practices in WoRMS, and will seek for advice from the WoRMS Steering Committee. The WoRCS Editor Group will select priorities for development of new tools in consultation with the WoRMS DMT and for data encoding. It will organize meetings, teleconferences (on demand by any of the Editor Group) and workshops, including an annual meeting to follow the yearly progress and to establish a working plan for the coming year.
Currently, only eleven thematic editors are in the WoRCS Editor Group (
Current Editor Group of WoRCS (* founding editors) with its roles in terms of taxonomy, management, types of caves and geographic areas.
Álvarez Noguera, Fernando*
Arthropoda (Anchialine caves, Central America, South America)
Chaetognatha, Pisces (Data management, Arctic, Southern Ocean)
Becking, Leontine E.
Porifera (Anchialine lakes and pools, Indo-Pacific Islands)
Crustacea (Anchialine caves)
Biota (Coordinator/networking, Marine caves, Mediterranean Sea, Sessile fauna)
Humphreys, William F.*
Animalia (Anchialine caves, Australasia)
Iliffe, Thomas M.*
Crustacea (Marine caves, Anchialine caves, North America, Caribbean Sea, Bahamas, Bermuda)
Crustacea, Thermosbaenacea (Anchialine caves, Mediterranean Sea)
Martínez García, Alejandro*
Biota (Marine caves, Anchialine caves, Atlantic Oceanic Islands, Africa, Cuba, Meiobenthic groups)
Porifera (Marine caves, South America)
van Hengstum, Peter J.
Amoebozoa, Foraminifera (Marine caves, Anchialine caves, North America)
Editors provide data and other documented expertise or assistance to WoRCS on a voluntary basis, as is the case for all the other taxonomic, geographic and thematic portals of WoRMS.
7.2. Ownership, IPR, licensing and related issues
WoRCS will follow the WoRMS rules (i.e. Creative Commons Attribution License, see Note to users). Like all editors in WoRMS, WoRCS editors were strongly recommended to sign the WoRMS Terms of Reference.
7.3. WoRCS specific policies
The few policies listed below are not exhaustive and can be extended by the Editor Group as needed.
7.3.1. Dissemination of datasets
Unless restrictions of usage are mentioned, data that were published by any media are considered to have potential to be integrated in WoRCS and disseminated through WoRCS / WoRMS / Marine Regions, and additional signed agreements with Third Parties if any. However, a case by case approach is always possible to address complex situations.
7.3.2. Different accuracy for locations for different users
The dissemination of the precise location of access points (e.g. entrances) to marine caves and anchialine systems has to be carefully evaluated case by case for possible conservation, privacy, and human security issues (especially regarding amateur and touristic diving).
General principles regarding coordinates: published coordinates are stored in the Gazetteer as they are presented in the relevant publications. Previously unpublished coordinates are recorded in decimal degrees with only three decimals unless more restrictive constraints are notified, e.g., by owner of the cave or system, touristic exploitation companies, natural park managers, authors of papers (scientific, magazine, newspaper, etc.), administrative regulations at any level, etc.
7.3.3. Data exchanges between WoRCS and editors’ databases
When editors will continue to maintain a separated database on their own with data that they provide to WoRCS, each editor will have to solve IPR issue separately with the WoRMS DMT. The usual issue of how to maintain the primary sources alive was raised by the WoRCS editors. One possibility is to use the connection with WoRMS as a leverage for fund raising, and to participate in projects. Technical issues may be raised, and may require the development of web services on the provider side, and client software on WoRMS side. This must be discussed on case by case basis. However, to facilitate further data exchanges, it is important that the personal databases keep the unique IDs used in WoRMS and Marine Regions.
7.3.4. Illustrations (photos, drawings, schemas, etc.)
General principle regarding photographs by WoRMS: Default usage of the Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.
Dissemination and outreach constitute priorities for the WoRCS Editor Group, aiming at the increase of global awareness on the diversity and significance of marine caves and anchialine systems. So far, the WoRCS initiative and its components have been or will be presented in following international symposia (see News section of the WoRCS webpage):
A Facebook group, entitled "WoRCS - Marine Cave Species" [405 members on 04/09/2016], and a Twitter account, entitled "WoRCS @CaveSpecies", managed by WoRCS thematic editors, have been created, with the aim to disseminate information on the marine and anchialine cave diversity of the world to the wide public.
During the 1st Editor Workshop that was held on February 2016 at the Flanders Marine Institute/ Vlaams Instituut voor de Zee (VLIZ), Oostende, Belgium, the WoRCS Editorial Team together with the WoRMS Steering Committee agreed on a strategic plan to ensure the development of the WoRCS database.
Every year, the Editor Group will discuss data encoding plans: (a) Gazetteer (b) by taxonomic group, (c) by geographic area, (d) on WoRCS in general. This discussion will take place in annual meetings, preferably organized back to back with other meetings/conferences, at least at the beginning of the initiative. LifeWatch financially supports the organization of a number of editor-workshops, related to filling remaining gaps in WoRMS for specific taxa or themes (including groups that deal with marine and non-marine taxa).
The priorities for data encoding will be decided on the basis of a list of driving scientific questions, which will be reviewed by the Editor Group on the basis of communication with the Editorial Team during the year. However, data should be hypothesis-free encoded as much as possible, and then datasets can be assembled for answering scientific questions. All data currently held by the eight founding editors will be integrated in WoRCS as an early step of that process. Records of species will be progressively linked to ecological, morphological, genetic and phylogenetic traits. Taxonomic and geographic coverage by editors will be completed through the expansion of the Editorial Team (i.e., all taxa are monitored by an editor, as well as all areas with caves).
Several strategies were discussed in order to raise the standing of WoRCS in the biospeleology and marine biology scientific communities. Short and mid-term plans to engage the scientific community included: (a) the development of common projects on marine and anchialine caves, especially in areas rarely or not studied yet; (b) the initiation of a fellowship programme to engage young researchers, (c) projects that would use WoRCS data, and (d) the creation or participation to learned societies (e.g., Formal Society for anchialine studies and Expert group on anchialine studies in Biospeleology Society).
However, WoRCS is also intended to develop educational, citizen science and conservation activities, by creating products (e.g., maps, guides, courses) for the public, engage volunteers to encode data, and develop tools for MPA managers and the conservationist community. This could be achieved through different funding partnerships and mechanisms. During the workshop the editors created a list of potential partners to be contacted. In particular, each time that a project about caves is funded, a work package or module or deliverable about WoRCS should be included to employ students and young researchers for data encoding, or to facilitate new types of data, or new links to other e-infrastructures and data tools.
The initiative was supported by LifeWatch, the E-Science European Infrastructure for Biodiversity and Ecosystem Research, through grants allocated by LifeWatch Belgium to the World Register of Marine Species (WoRMS) developed and maintained in VLIZ. LifeWatch Belgium provided the funds to VLIZ to host the 1st Editor Workshop through a competitive grant mechanism. LifeWatchGreece provided the staff time for the global workshop organization: V. Gerovasileiou and N. Bailly. LifeWatchGreece infrastructure (MIS 384676) is funded by the Greek Government under the General Secretariat of Research and Technology (GSRT), ESFRI Projects, National Strategic Reference Framework (NSRF). VLIZ provided the staff time for the workshop organization on site: W. Decock, L. Vandepitte, S. Dekeyzer, B. Vanhoorne; and Nathalie Keersebilck.
We thank the Marine Regions Data Management Team, Francisco Souza Dias and Nathalie De Hauwere for their introduction to the Marine Regions initiative and useful discussions about the integration of caves in the Marine Regions Gazetteer (MRG) during the 1st Editor Workshop and Bern Szukalski (ESRI) for his help with mapping options. We are grateful to Emmanouela Panteri (HCMR, LifeWatchGreece) and Gerald Hughes (Texas A&M University at Galveston) for designing the WoRCS logo and Brett C. Gonzalez, Brian Kakuk (Bahamas Caves Research Foundation), Curt Bowen (ADM Foundation), Jill Heinerth (Into the Planet), Joerg Hess and Joris van der Ham who provided photographic material for the WoRCS Photogallery. VG, AM and NB would like to thank Christos Arvanitidis for his support and Eleni Voultsiadou, Brett C. Gonzalez, Diego Fontaneto and Katrine Worsaae for their contribution to the compilation of the individual databases on marine cave biodiversity. AM database was funded by the Carlsberg Foundation (Grant # 2013_01_0779).