Chagos Islands coral collections

The Chagos archipelago, part of the British Indian Ocean Territory, is a largely uninhabited area that contains the largest coral atoll in the world. It is an ideal place to study the effects of climate change and ocean acidification on the local biota without the confounding factors that affect many other coral reef ecosystems - such as pollution and overfishing.

The reefs are generally considered to be quite healthy. The environment has very low pollutant levels and has been suggested that as a whole, the archipelago is ‘exceptionally pristine’ (Everaarts et al. 1999) and could be used as a ‘global reference baseline’ (Guitart et al. 2007). Currently, there is a push to make the Chagos archipelago a marine protected area.

The Chagos Islands coral collections at the Natural History Museum are likely to be the best collection of mid-Indian Ocean corals anywhere in the world (written communication from PS Davis, 1977).


Organisms included:
  • Scleractinian corals
  • In addition to scleractinian corals, the 1978-9 expedition collected and documented foraminifera, hydroids, gorgonians, alcyonaria, echinoderms, molluscs and fish.
Timespan covered:

Specimens were primarily collected from three expeditions to the islands in the 1970s:

  • Joint services expedition to Egmont Island (JSEI): 1972-3
  • Joint services expedition to Danger Island (JSDI): 1975-6
  • Sheppard expedition: 1978-9
Collection location:

Natural History Museum, London

Curation and collection management

Preservation and storage:

The 6,167 dry coral specimens are stored in plastic bags within 84 large boxes.


Nearly all specimens have labels from their previous storage area, the Tyne and Wear Museum (Natural Sciences). These include a space for:

  • genus and species / type
  • determination
  • expedition and collection date (year)
  • collection locality
  • depth and transect
  • accession number
Database information:

An Excel database of all coral specimens collected from each expedition is available:

Specimen-level Chagos Islands coral collections database Excel (658.5 KB)

Using the database we have found that, of the specimens in the collection:

  • 826 (13.4%) are in ‘poor’ condition
  • 2166 (35%) are in ‘good’ condition
  • 3073 (50%) are in 'fair' condition
  • 102 (the remainder) have not been given a condition status

Further information is available in L Bennett (1983).

Supporting information

Full reports of the Joint services expedition to Danger Island and the Sheppard expedition are available. 

Along with other metadata associated with the expeditions - such as transect and depth details, species lists, detailed maps and specimen photographs, they contain all the information needed to repeat the surveys and experiments for targeted questions about the effects of climate change and other human impacts.

In the time period following the original collecting and surveying expeditions, multiple reports and publications were prepared concerning the ecology and environment of the Chagos Islands (see Sheppard et al. 2009 for an overview).

Contact information

Miranda Lowe
Zoology Department
Natural History Museum, London


Excel files

If you are unable to open the Excel file please contact the Curator to request the document in another format.