By: Dr Brian Lassig , Category: Science, Date: 26 Mar 2014
Museum natural history collections can help answer many questions, but how do we ensure they continue to be relevant?
In answering questions about the natural world, scientists often turn to the collections held in natural history museums like ours. Indeed, that’s why we collect specimens in the first place.
One well-known example is the study of the bird egg collection at the Field Museum in Chicago in the 1960s which determined that shells of Peregrine Falcon, Falco peregrinus, eggs had become thinner and more fragile since the introduction of DDT for agricultural use. Subsequent work showed that DDT interferes with calcium production in female birds causing them to lay thin-shelled eggs which were more likely to be crushed during incubation. With levels of DDT bioaccumulating in the food chain, it was top predators like the peregrine that were being most affected.
The study helped us understand why populations of this magnificent bird had declined so drastically, and it resulted in the US government banning the use of DDT for agricultural purposes in 1972. It is crucial to note though that the Field Museum’s collections were made over manydecades without this specific question in mind; yet without such a long time-series of collected specimens the reason for the peregrine’s decline might not have been discovered in time.
There are many such uses of collections and collection data. To give some idea of the scope and depth of these applications, we can analyse downloads of nearly 750 million records from the Atlas of Living Australia (the shared repository of collection data from many Australian natural history museums). The broad categories of these uses include not only scientific research and education, but many applied uses such as conservation management and planning, environmental impact assessment and biosecurity management.
It is reassuring that some decision-making appears to be based on the available scientific information, but the analysis is not all that helpful in understanding exactly what users are trying to discover. Perhaps the most pressing question we’ve been asked recently is: what can our collections tell us about the impact of climate change?
The question coincided with the release of the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report into the physical science behind climate change. The IPCC report identifies a number of significant and disturbing environmental changes over the last 100 years or so. Surely the magnitude of these changes should be forcing radical changes to our biodiversity – but is there any evidence?
To answer that question, the Australian Museum Research Institute (AMRI) recently hosted a seminar to find out what museum collections can reveal about climate change. We now know, from a study of over 300 species, that the ranges of marine and intertidal molluscs (essentially snails) have been shifting south along the east coast of Australia on average by about 10 kilometres each decade as water temperatures have increased. Some species have shifted at 10 times that rate.
One mussel species studied by Museum scientists now has a much narrower range and is likely to be lost from New South Wales if trends continue. Also, the body size of marine snails has decreased over time, probably as a result of increasing acidification of the ocean. Species that have only ever been recorded around mainland Australia have started appearing in Tasmania – even the Blue Groper, the NSW fish emblem, whose southern-most distribution was previously recorded as at Wilson’s Promontory in Victoria. On land, species living in the cooler montane areas are at grave risk as temperatures rise and the available area of suitable habitat shrinks.
A guest speaker at the AMRI seminar, Professor Craig Moritz from the Australian National University, presented a fascinating case study that highlighted the value of planning for future needs. In the early twentieth century, Joseph Grinnell, founding Director of the Museum of Vertebrate Zoology at the University of California, documented and collected vertebrates from more than 700 locations across California and adjoining states. Scientists re-surveyed Grinnell’s sites just a couple of years ago and found a range of climate change impacts among mammals. For example, formerly low-elevation species had expanded their ranges and high-elevation species had contracted theirs, leading to changes in the composition of ecological communities at mid- and high elevations.
Such is the power of systematic and strategic collecting.
Collecting for the future
The Australian Museum’s collections date back to 1828 and include many different animal groups, from worms to wallabies. But, like the Field Museum's, our collections were not accumulated to answer questions about climate change. There are often big gaps in the time series of collected specimens; collections from single localities are generally not repeated over time; species absent from particular places are usually not recorded; and those species that are collected may not be strongly influenced by the local climate.
It is clear that museums should be developing long-term collection programs so that we can more confidently respond to these sorts of questions in the future. So now we have a new challenge: while continuing to document the breadth of Australian biodiversity we need to review how we go about collecting. We need to ensure that we have adequate baseline information so we can be prepared to answer different questions about biodiversity, some of which we know about and others that we can’t even begin to guess!
Dr Brian Lassig, Assistant Director, Science and Learning Division, and Head, Australian Museum Research Institute
First published in Explore 36(1), 2014
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