A guest blog by Kate Holub-Young
Our pinned mayfly, stonefly and caddisfly specimens are groups of insects that have life cycles reliant on freshwater. Where these insects are plentiful, they are fantastic indicators of water quality.
As August is Water Quality Month and with some major milestones reached in digitising this collection, we wanted to share our progress on how our pinned freshwater insect digitisation project is coming along.
Earlier this year we wrapped up some of the final stages of one of the largest pinned insect projects undertaken by our digitisation team. The goal was to digitise over 77,000 of our freshwater insects and release the data publicly onto the Museum’s Data Portal.
Why digitise Freshwater Insects?
We’ve been sharing details about this project since it started (you can check out our previous blogs for a more detailed introduction to the project)
But for a quick recap: Mayflies, Stoneflies and Caddisflies are also known as Ephemeroptera, Plecoptera and Trichoptera (EPT). They are more generally known as being types of freshwater insects, or riverflies. These species spend the majority of their life cycles in freshwater systems. As a result, they usually prefer clean water and are very sensitive to environmental changes. Due to this, they have long been used as bioindicator species. Their presence and population size can reveal the status of the environment, in this case water quality. This project has been funded through the SYNTHESYS+ Virtual Access programme.
Freshwater systems are vital to the survival of human and wildlife health alike, and monitoring the quality of those systems helps us understand areas of concern. In light of issues like climate change and biodiversity loss, water quality and its decline is just one of the challenges we face. The methods we use to monitor those freshwater systems are key for understanding how, where and what we’re affecting as a species, and utilising our knowledge of bioindicators is just one of the ways we can do that. By digitising our collection, we’re able to publicly share that data in more accessible ways than ever.
Before starting this project it was estimated there were about 65,000 pinned EPT specimens. Now, we know there are over 77,000 of them. Through digitisation, we also now know our collection covers over 3000 species, with specimens from over 130 countries (from every continent except Antarctica) that were collected from as far back as 192 years ago, making it one of the world’s biggest and most diverse collections of its kind.
How did we do it?
Efficiently digitising an old and historic collection poses its challenges. From delicate specimens and overcrowded drawers, to individual mini-collections within the bigger one each with their own organisational quirks, we had to work on finding standardised ways of imaging an unstandardised collection.
On top of that, taking photos of 77,000+ specimens would normally take years, but using a skilled team of digitisers and some novel set-ups, we managed to get it done in a matter of months. With a collection so large, and a big team of people to work on it, we split the main tasks up to maximise our time.
Task 1: Pre-Digitisation & Rehousing
A collection will almost always need to be prepared in some way before it can be digitised, with how intensive and time-consuming this task needs to be dependent on a lot of factors.
For the EPT collection, we needed to prepare the specimens first through barcoding and rehousing.
Attaching barcode labels to each specimen is a key step in databasing and tracking our specimens. These barcodes are unique to each individual in this collection, and are a way of consolidating all of the information we collect on a specimen into a digital record. These barcodes are essential for us to track each individual and we use them in the next stages of imaging.
We also took the opportunity to rehoused the specimens into improved housing to help extend the life of the physical collections as we created the new digital one. The majority of the collection was previously kept in old cork-lined drawers, often with overlapping delicate specimens that were hard to get out and image quickly without damaging the specimens. Cork in particular poses long-term conservation issues to the pinned insect specimens, with the cork itself often causing degradation of pins and damage to specimens through verdigris. This is reaction between copper and acid that can make pins brittle and easy to break.
Task 2: Imaging
For this project, we utilised one of the teams’ novel ways of imaging insects: Angled Label Image Capture Equipment (ALICE.) ALICE is essentially six cameras staged around a central point, angled to take photos of the specimen still on its pin, whilst capturing the vital data present on its labels.
Using the barcodes we’d attached during the rehousing phase (and few more to track the basic data on the taxonomy and location within the collections), we used these images to create the new specimen records in our database.
The images were then passed on to the transcription phase of the work, where the team were able to extract the rest of data from the images of the labels.
Task 3: Transcription
Using the different angles captured by ALICE, our team worked through transcribing the labels of each specimen in the collection. The most important data for this project were when and where the specimen was collected.
Once consolidated and cleaned, all of the label data transcribed will eventually be added to the Data Portal. But in the meantime, all of the ALICE images and basic record details are now up for you to explore.
Learning for the future
In a Museum predicted to contain over 80 million specimens, projects like this one not only get us closer to digitising this collection, they help us learn about how exactly we’re going to do that.
The EPT project has helped us to better understand some of the quirks of old collections with a patchwork of curatorial history, as well as the possibilities and limits of innovative workflows like ALICE. Beyond that, the data from the project itself will be used by the IUCN Species Specialist Group for Riverflies as evidence for redlisting and conserving species from around the world. To keep up to date with the work from the group, you can follow them on Twitter.
Want to learn more about global water quality and the issues we face? Check out the UN Environment Programme’s report on world water quality.
Keep up with all of the varied projects our digitisation team work on? Follow us on Twitter and Instagram for updates on our work.
Want to see what we’ve already digitised? Check out the Museum’s Data Portal to explore.