If you want to measure the quality of the environment, measure the biodiversity it supports. Knowing how many species live in a given place tells you something about its nature.
For this reason the huge collection of species held and catalogued in the Natural History Museum is an invaluable resource for the study of biodiversity. Most specimens have details of where and when the sample was found. Past records of diversity can be compared with more modern diversity patterns to assess how things have changed.
An important new collection presented to the museum only last month shows how this works. While the star of the collection, non-biting midges, may not seem very exotic, the records that accompany each of the almost 600 slide-mounted insect samples potentially tell researchers about water quality and environmental conditions where the insects were found.
The collection was put together by Dr Declan Murray, a retired senior lecturer in zoology at University College Dublin's School of Biology and Environmental Science, using a grant provided by the National Heritage Council.
The bugs in question, chironamidae, are also known as dancing midges, duck fly, buzzers or silver hawthorn. "I started looking at these insects in the 1960s as a PhD student," Murray says. He is still at it more than 40 years later. "It is like stamp-collecting."
He already had a substantial personal collection assembled over the decades and the Heritage Council grant allowed him to add to the collection and catalogue it in detail. The Heritage Council Collection of Irish Chironomidae now sits in the Natural History Museum and includes 405 non-biting midge species of the 495 known to exist here, he says.
The collection provides a permanent physical record of the chironomid family as found here at this time. It represents a baseline for future comparisons, but also provides a highly detailed sample book for identifying species. Students studying these midges can now bring in samples and identify species by comparing them with examples in Dr Murray's collection.
Time will tell if future students using the collection are as lucky as Dr Murray, who discovered a species of chironomidae that was new to science. He found it "literally on my doorstep" close to his home in Co Meath. It is a member of the Limnophyes genus and the new species name will shortly be published in a peer-reviewed journal.
Such collections are extraordinarily important for the study of ongoing biological diversity, says Dr Murray. While assembling a collection can take years, the result is a valuable resource that should continue providing research information for centuries, much as the collection already held by the Natural History Museum, some of which dates back to the 1700s, does today.
The Heritage Council backed the project as a contribution to the "national species inventory", an obligation arising from Ireland's signing of the UN Convention on Biological Diversity. The council is now backing Dr Murray again. He has already embarked on the building of a complete database of the distribution of non-biting midges across Ireland.