Every year, the question most commonly asked at the Australian Museum’s Open Day is: why do you need so many specimens in jars?
There are many answers to that question, and to some extent, they vary among types of animals, so I’ll focus on fish – the group I know best. Museum collections are used to address many scientific subjects, ranging from biodiversity inventories to climate change, and this contributes to a need for a range of specimens and life-history stages from different places and times.
At present, somewhat more than 5000 species of fishes are known from Australian waters – more than 75% of Australia’s vertebrate fauna. The age of discovery of the Australian fish fauna is far from over. Ichthyologists discover a fish species previously unknown in Australian waters at the rate of about one per week, and this rate has remained relatively constant for decades.
To document these newly discovered Aussies, specimens are needed from which to take measurements, counts, and DNA samples, and to describe their colour and other features. A photo, or even several, is usually not enough to be certain that a fish is really new, particularly in the tropics where there are many closely related species and often strong differences between sexes, and for the smaller, really similar-looking species, which in many families, make up the bulk of the species.
The initial reason for maintaining museum collections is to establish how many species there are, to describe them and to determine their relationships: in short, to conduct taxonomic research. But, museum collections are also used for many other purposes beyond documentation of our fauna.
Studies of food habits, reproduction, functional morphology, community structure and parasites are also conducted on museum specimens. The effects of climate change can be investigated using Museum specimens, by studying how distributions of various species have changed over time, and measuring how body size has changed. We can even investigate how pollution has changed over time by measuring contaminants such as mercury in museum specimens collected 20, 50 or even 100 years ago.
Most marine fish species, like most marine invertebrates and terrestrial insects, have a larval stage that differs greatly in morphology from the adult, and that frequently lives in a different place, eats different foods and has different behaviours. In order to study the development of larvae, how they grow and change, how to identify them and what this tells us about their relationships, large numbers of specimens are needed, because the essence of larval development is change, and a 5-day-old larva will be very different than a 15-day-old larva.
Large numbers of fish larvae are collected in fishery biology studies, ecological studies and environmental impact studies, at very large cost in terms of ship time, and staff time to sort and identify them. In Australia, Regional Larval Fish Archives have been established at state museums and the CSIRO National Fish Collection. The valuable larvae from such studies are deposited into the Archives, where they are available in future not only for the types of studies for which museum specimens are normally used, but also for studies to determine how fish populations have changed over time, or with changing environmental conditions.
All scientific collecting is overseen by Ethics Committees, and requires permits issued by responsible government authorities. In fact, scientific collecting is much more regulated than are either commercial or recreational fishing.
There are many reasons why researchers collect specimens, and tight controls over how it is done. Museums collect specimens and manage those collections as a resource for not only Australians, but also the world. Museum collections are available for study by bona fide researchers at home and overseas for research to help answer questions about natural history and evolution, and to help solve conservation problems. They and their curators are a vital resource.
Dr Jeffrey M Leis
Senior Fellow, Ichthyology
A recent publication in the prestigious international journal Science has questioned why traditional museum collecting is needed (Minteer et al. “Avoiding (Re)extinction,” Science, 18 April, p.260), in much the same way that Open Day visitors have done.
A response by 122 scientists from 65 museums, universities and other scientific institutions round the globe, published in Science last week addresses this question (Rocha et al. “Specimen collection: An essential tool”. Science, 22 May, P814-15).