Research by the University of Leeds and the University of Essex has found that the rapid melting of glaciers due to climate change is threatening biodiversity in the European Alps.
The team behind the study has called on conservationists to find new measures to protect aquatic biodiversity, after finding that species living in cold meltwater rivers will be pushed to higher altitudes. Near the mountaintops, these organisms are likely to face pressure from tourism businesses.
The invertebrates studied are crucial to the alpine ecosystem, being a key part of the nutrient cycle and making up an important part of the diet of birds, mammals, amphibians and fish.
Rapid glacial melting in the Alps are likely to drive some invertebrate species extinct in the rivers that feed the Danube Basin (Tiia Monto via Wikimedia Commons).
Scientists from across Europe simulated the likely changes in key invertebrate populations in the Alps between now and 2100 in response to climate change. The modelling, based on landscape, biodiversity and glacier mapping data, predicted the invertebrates would be pushed to the highest altitudes of the mountain range.
These highest points are also likely to become sought-after areas for winter sports complexes and other tourism infrastructure, potentially putting further pressure on the invertebrates studied, which included stoneflies, midges and flatworms.
Lee Brown, Professor of Aquatic Science at University of Leeds and co-leader of the study, said: "Conservationists need to be thinking about how protected area designations must evolve to take into account the effects of climate change.
"It may be that some species will have to be moved to refuge areas if we want to safeguard their survival as many of them are not strong fliers so they cannot disperse easily through the mountains."
Anticipated changes in glacier and river flows were mapped alongside the distributions of 19 mainly aquatic invertebrate species over an area of more than 34,000 sq km.
Co-author Jonathan Carrivick, from the School of Geography at University of Leeds, said: "We have quantified that as glaciers melt and retreat, the rivers running through the Alps will experience major changes in their water source contributions.
"In the short term, some will carry more water and some new tributary rivers will form, but over several decades from now – most rivers will become drier, flow slower and become more stable, and there could even have periods in a year when there is no water flow. Additionally, most water in Alpine rivers will also be warmer in the future."
The team predicted that most of the species studied would suffer 'consistent losses' of habitat by 2100. Three species of non-miting midge, the stonefly Rhabdiopteryx alpina and the mayfly Rhithrogena nivata are expected to be the hardest hit. On the other hand, one species of flatworm and the flat-headed mayfly Rhithrogena loyolaea are expected to benefit from habitat changes driven by glacial melting.
The researchers say that 'substantial work' is needed to conserve the biodiversity of rivers being fed by retreating glaciers. They warned that areas where glaciers will still exist at the turn of the century are likely to be earmarked for hydropower dam construction, as well as winter sports infrastructure.
Dr Martin Wilkes, co-author from the University of Essex, said: "The losses we predict for Alpine biodiversity by the end of this century relate to just one of several possible climate change scenarios.
"Decisive action by world leaders to reduce greenhouse gas emissions could limit the losses. On the other hand, inaction could mean that the losses happen sooner than we predict."
Wilkes, M A, Carrivick, J L, Castella, E, Ilg, C, Cauvy-Fraunié, S, Fell, S C, Füreder, L, Huss, M, James, W, Lencioni, V, Robinson, C, & Brown, L E. 2023. Glacier retreat reorganizes river habitats leaving refugia for Alpine invertebrate biodiversity poorly protected. Nature Ecology & Evolution. DOI: 10.1038/s41559-023-02061-5