Identifying whale bones

Human hunting has brought many whale species near extinction, yet the acute modern phase emerges from hunting practices going back thousands of years. Studying the remains of hunted animals could provide historical population data and other information, which may aid present-day conservation.

However, such investigations are not simple. A need exists for rapid and inexpensive biomolecular approaches that accurately identify whale species from their remains.

The EU-funded 'Optimizing research tools for cetaceans in archaeology' (ORCA) project aimed to develop two such methods: Zooarchaeology by Mass Spectrometry (ZooMS) and ancient DNA analysis. Both methods were to be convenient and low cost, and applied to study of whale species ecology and hunting patterns over the last 4 000 years. The single-member project ran for two years to September 2014.

Work began with testing a new ZooMS protocol, comparing collagen peptide fingerprints against known samples. Following training, project researchers refined the ZooMS technique by comparing whale collagen remains against known museum specimens. The results were combined with recently published data to create a whale collagen database, hence verified against archaeological whale remains. Comparison of ZooMS against DNA techniques established that ZooMS consistently yielded accurate identification to family or genus level, but could not discriminate closely related species.

Comparison of ZooMS and DNA microsampling approaches showed that the former did not consistently yield sufficient collagen for unambiguous identification. However, the DNA technique could reliably identify species using samples as small as 3 mg. The microsampling technique was successfully demonstrated using a 1 000-year-old bone artefact.

Certain samples could not be identified morphologically but were identifiable using the project's techniques. The identifications led to revision of interpretations concerning prehistoric species distributions, and human preferences, in the Mediterranean and South Atlantic. Further optimisation of hybridisation-capture approaches will be necessary before ancient DNA samples can be used for demographic modelling.

The ORCA project contributed to both archaeology and conservation biology issues. The research illustrated the long history of whale hunting, while providing valuable data applicable to modern whale conservation and management.