Artefacts offer Pacific shark species absence clues

By Mark Kinver, Environment reporter, BBC News

Historical artefacts, such as this shark teeth weapon, are an "under-utilised source of data"

Nineteenth Century tools made from sharks' teeth suggest that two species of shark used to populate the Central Pacific but are no longer present.

Using artefacts from museums, a team of US researchers found that spot-tail and dusky sharks used to inhabit the reefs surrounding the Gilbert Islands.

The unusual historical data would help evaluate the success of ecological conservation measures, they added.

The findings have been published in the scientific journal PLoS One.

In their paper, the team from the Field Museum of Natural History, Chicago, and Columbia University, New York, said indigenous artefacts often represented an "under-utilised source of data".

"By examining the materials... we can gain access to the flora and fauna present during the time of their construction," they wrote.

"When these materials are assigned to a particular species, they can indicate which species were present in the past."

They said historical artefacts could be used to provide important insights in the absence of historical ecological data and provide an important first step in the assessment of the effectiveness of current conservation methods.

They observed that as shark teeth were "diagnostic to species", the artefacts allowed the team to identify some of the species that where present in the waters around the islands when the weapons were manufactured, between 1840 and 1898.

Continued:  http://www.bbc.co.uk/news/science-environment-22005634