New uses for old collections
Can biological collections help us to understand ecological and environmental issues? asks Museum research scientist Graham Pyke.
In the 1960s, US scientists concerned about a decline in populations of birds of prey showed a link between the increased use of agricultural pesticides and a decrease in the thickness of egg shells.
The shells came from museum collections that pre-dated the widespread use of the pesticides in question, DDT and its derivative DDE. The scientists showed that thinner egg shells led to an increase in mortality of young birds and a decline in the populations of adult birds.
This research led to a ban on the use of these pesticides and was one of the earliest examples of using museum collections to answer environmental questions.
I have recently been using museum collections of the common Striped Marsh Frog, Limnodynastes peronii, to similarly evaluate their role in providing bio-indicators of environmental quality and change.
I hypothesised that chemical pollution of the frog’s aquatic breeding habitat would have peaked during the 1960s or 1970s, and that the incidence of physical abnormalities (including missing body parts and differences in symmetry between left and right sides of the body) for this frog species would tend to increase with increasing pollution.
By examining specimens from the Museum’s collection, I showed that this was indeed the case: the proportion of frogs with physical abnormalities peaked for specimens collected during the 1960s or 1970s and was lower for specimens collected during earlier and later decades.
In this and similar ways, biological collections may be ‘mined’ to provide useful environmental information and insights because each specimen has associated with it useful data such as the place and date of capture.
Using collection data, I am also looking at changes in the distribution of the Striped Marsh Frog and another common frog, the Common Brown Froglet, Crinia signifera. Both species are very well represented in frog collections over the last 50 years, a period for which significant climatic changes have already occurred. Combining records from the Australian Museum (about 1500 for each species) with records from other museums provides a sample size of over 10,000 recorded locations for each of these species. Any changes in distribution offer an opportunity to understand the effects of climate change – an opportunity that exists only by virtue of these existing museum collections.
These examples are part of a considerable and increasingly realised potential for research based on biological collections. An increasing number of scientific articles published over the last 30 years – about 500 by my count – report or discuss the use of biological collections in addressing environmental issues.
This trend further increases the relevance of biological collections and makes them deserving of greater recognition, support and funding.
Dr Graham Pyke is a Senior Fellow at the Australian Museum and an Adjunct Professor in Biology at Macquarie University.
First published in Explore 31(4).
Michael Hugill , Online Producer