History and scope

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Virtually all reef conservation decisions over the past decade have had as a primary consideration species diversity and the occurrences of particular groups of species, including threatened species. Scleractinian corals, the fundamental components of reefs, have been central in this, a role likely to be further extended over the forthcoming decades as the effects of climate change become increasingly apparent.

The central and most challenging task of this website has been to bring the taxonomy of all zooxanthellate Scleractinia into a coherent and consistent framework. If this was a matter of creating a catalogue of all names that have been used in the plethora of taxonomic studies that have been undertaken over the past two centuries such a task would have been significant but relatively simple because most of this information already exists. However, such an undertaking would not have supported the core operations of this website which require that all species be given a single identifying name wherever they occur. Only when this is done can we know how species can be distinguished from each other, their distributions mapped, and patterns of diversity and affinity determined. Furthermore, only when this information is made readily accessible to non-specialists do we have an effective foundation for conservation and management and for the many needs of other user groups.

Most people who take an interest in reef-building corals know that they can be difficult to identify especially as their appearance changes according to the environment in which they occur. It may also change with location or country. This has made our task very challenging for we have had to assess the work of others, integrate it, and then produce outcomes that are as inclusive as possible yet are accurate and meaningful. There is nowhere to hide in this process; it has taken ten years to reach initial release during a period of rapid and extensive taxonomic revision, yet the task has no end in sight because Nature is endlessly complex and there are always more details to discover and faults to correct.

This website should not be seen as an amalgam of facts. Certainly it is grounded in the best that science has to offer, but it should be seen as a hypothesis; one to be built on when new information becomes available and changed where found to be at fault.

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This website is not the first attempt at the task just described. Three earlier products have played a key role in this process.

  1. The three volume all-colour book, Corals of the World, published in 2000
  2. A mapping project, Coral Geographic, commenced in the late 1970s and used in the 1990’s to generate the global diversity map of species that revealed the existence of the Coral Triangle. The program was then used to generate the thumbnail species distribution maps in the Corals of the World books as well as maps in many publications of other authors
  3. A CD-ROM Coral ID which allowed all living reef-building corals of the world to be identified and their characteristics documented

These products have serviced hundreds of research projects and conservation initiatives and have underpinned decision-making on the part of NGOs and governments involved in reef management for over two decades. However, since their publication, scientists have undertaken an unprecedented amount of fieldwork, molecular methods have come to the fore, and the Coral Triangle has been delineated.

Work leading to this website was initiated in 2006 when it became clear that the abovementioned publications were going out of date and that only a website could be (a) freely available to all users, (b) fully comprehensive, (c) up-to-date, (d) have all components interlinked and (e) generate products according to user needs. During development the authors have been privileged to receive enormous support from hundreds of individuals and many organisations (see Acknowledgements). It certainly would not have been remotely possible without them.

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In concept, this Corals of the World website has five central pillars embracing

  1. Coral taxonomy (which underpins all other elements of the website - a reassessment of all existing reef-building species and recently used names, summarised in the Taxon Finder tool – at Beta stage)
  2. Coral distributions (Coral Geographic – at Beta stage)
  3. Coral identification (Coral ID – in preparation), and
  4. More complex coral investigations (Coral Enquirer – under development)
  5. In each case the tool has as its principal end point and its foundation as the fifth component of the website, the Species factsheets (– at Beta stage) which summarise and expand on the information relating to individual species
A range of ancillary factsheets and tools varying in complexity interlink these pillars to give users easy access to the data that underpin all operations of the website.

1. Coral Taxonomy. Despite its problems, the taxonomy of corals is in a relatively advanced state compared to most other major marine invertebrate goups. Nevertheless many problems arise when taxonomists seek to impose order on what are essentially the genetic continua occurring in Nature. See Website policy for a brief description of the focus of our taxonomic decisions: in essence we embrace what occurs in Nature rather than human-created regulations should these be in conflict. All users are free to make up their own minds about such matters; see Overview of coral taxonomy for an account of this multi-faceted subject.

The Taxon Finder tool not only underpins the species and entities classified as 'accepted' on this website, but it will also guide users from a name not used in this website to one that is, should that be possible. It includes synonyms of accepted species as well as names linked to lost or damaged specimens, images or descriptions that cannot be resolved with existing information. Further study or publication of additional details may well give them future acceptance.

Note however, that the Taxon Finder provides synonymies based only on the original description and type specimens associated with a name. Except in unusual cases (such as inclusion of a mis-named real species which does not yet have a valid name) it does not attempt to include all the uses and misunderstandings of names used by subsequent authors. The latter usage is often exceedingly complex and traditionally involves disagreement amongst taxonomists; see Overview of coral taxonomy for further information.

2. Coral Geographic does not contain static maps but rather uses website technology to construct maps according to the user's requirements based on the occurrence of each species in 150 coral ecoregions globally.

The use of ecoregions is fundamental to spatial aspects of the website’s design and operation. Whilst it is a future goal to refine geographic data to more detailed spatial scales, at the present time the error rate in identification, especially of lesser known, cryptic, or difficult species, does not support species level global analysis at more detailed scales. Ecoregions have their own unique issues, but they represent a good compromise to allow reliable taxonomic and distribution data to be pooled from many sources to address global questions. The use of ecoregions is thus limited only by the comprehensiveness of the data they contain. It is important that scientists using these data understand the limitations of ecoregions, see Methodology and data limitations under the Coral Geographic menu.

Importantly, Coral Geographic is open-ended: users will increasingly be able to overlay map layers representing data of various types (from the website or from their own sources) in order to address biospatial questions. Coral Geographic is continually being updated to accommodate new information and also to increase its analytical capabilities. Maps of coral species abundances are currently in preparation.

3. Coral ID is not yet operational. When added to the website, Coral ID will use the many functions of Lucid, the program on which the original CD-ROM version was based. We know that this is an important aspect of this website and will keep registered users informed about anticipated release dates. The morphological detail of species this program uses will be published separately in a new, more detailed descriptive page within the factsheets of each species.

Coral ID will enable people from all walks of life to identify corals far more reliably than previously possible. In ways analogous to birdwatchers accumulating information about birds, the many thousands of knowledgeable divers that visit reefs every year, commonly with cameras, will be a significant source of detailed and anecdotal information about changes in coral species distributions and abundance. Coral Geographic will track this information and use it in tandem with our own detailed abundance studies to indicate when and where further surveys are needed and to track reef deterioration.

4. Coral Enquirer is the target tool of this website and will be the last to be operational. It will be capable of amalgamating all relevant science including, but not limited to, the content of this website in order to access the vulnerability of all species to regional or total extinction. Key components will be (a) the distribution and abundance of species, (b) the characteristics of habitats, (c) environmental data including temperature regimes, (d) maps of mass bleaching, disease and other impacts, (d) the biological traits of species and (e) the connectivity of ecoregions via ocean surface circulation.

5. Species factsheets are generally the ultimate target and also provide the foundation for of all of the other tools of the website. They give straightforward accounts of all species we recognise as accepted. At the present time they include three principal pages: (a) a summary page with general description, taxonomic notes, brief accounts of habitat, abundance, similar species, Corals of the World history, and references, along with image thumbnails; (b) global distribution; and (c) images. The image page includes both underwater photography of living corals as well as photographs depicting skeletal detail. Location-specific photography will be a primary focus of website development.

A number of additional Factsheet pages are in preparation. These cover more detailed descriptions, taxonomic history and issues, molecular studies, abundance, conservation status and user pages, among others.

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Versioning and transparency

This website is versioned. Such versioning is not simply a question of publishing a new release when new functionality is added. Rather, all data across the website (with the exception of Coral ID which will call on the latest data for its analysis) is maintained in a series of saved versions which registered users can access at any time through their login area. If you are working on a research project which is accessing distribution data for species published in say, v2.36 and a new version v2.40 is released which has significant changes to that distribution data, you can set your default preference to be viewing v2.36 and continue to access the data within that version as if nothing had changed. Once a version is published, the data within it cannot be altered. For further details about the contents of versions see Versioning The first permanent version of the website will be Version 1.0.

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Private user areas

A key target of the authors is to provide users with the capacity to integrate their own knowledge, images, data, map layers, biases and preferences into this website and use the tools and information we provide in personalised ways. Such additions will be private and only accessible to the user and their user-defined group. Some user elements are already available including the capacity to create and save species lists. These will be progressively enhanced to include ecoregion and GIS map layers, additional species pages and/or images for local variants or for species which we do not currently recognise. The feedback forms can be used to advise us of ideas and suggestions to benefit users. Where images, knowledge or other information would enhance or correct website data, users are encouraged to make it available to us via feedback.

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Devices for accessing this website

We are acutely aware that many users will have need of this website in places where there is limited or no internet access. Some components of the website, notably Coral Geographic, require this access and its use is unavoidably limited to places where the internet is available. Most importantly, internet access is usually unavailable in field situations where Coral ID is commonly used. We plan to circumvent this problem and will advise registered users when solutions are available.

We anticipate that this website can be used on any modern computer as well as on notebooks, tablets and mobile phones. Use with devices that have very small screen sizes including mobile phones may have reduced information on display, so it is recommended that users assess this individually by comparing their phone with a the data displayed on a larger device.

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