Then and now: Citizen scientists help assess the changing biodiversity of minnows in Austria

The minnows of the Phoxinus genus were long thought to be a single species, as even experts found it difficult to distinguish them by external features. In the last 20 years, however, their status has changed dramatically as molecular studies have revealed a high level of genetic diversity within this group of fish. Currently, more than 23 genetic lineages are known in Europe, of which 14 are recognised as valid species. In Austria, instead of one common minnow, studies have revealed at least four species, three of which are presumed native and one introduced. The Citizen Science project “Biodiversity of minnows in Austria”, funded by the Federal Ministry of Education, Science and Research as part of the “Sparkling Science 2.0” Programme, aims to collect and analyse the missing data to determine the number of minnow species swimming in Austrian waters. With the help of pupils from six different schools across Austria, fisheries associations and numerous independent fishermen, the minnows are being sampled extensively and their genetic lineages determined. Basic data on their habitat is also being collected using standardised forms. At the same time, the project team is analysing up to 200-year-old specimens from the fish collection of the National History Museum in Vienna to assess the rate of change in the minnow’s biodiversity. Our initial results confirm the native distribution of three minnow species in Austria and show several mixing zones between them, which may not be natural. This is therefore a study of change: on the one hand, changes in genetic diversity over time are evaluated. On the other hand, it highlights the changes that new methods are bringing to our scientific and general knowledge about biodiversity. One of the most dramatic consequences of human impact on our planet is the continuing loss of global biodiversity. What better way to experience these changes than by actively participating in a study designed to assess them?