Dupanier\u2019s team were shocked when they discovered the extent of the invasion in 2022. \u201cWe had this denial about what was happening,\u201d he says. The quaggas had only been detected in Lake Geneva six years previously<\/a> and already they had spread like wildfire.<\/p>\n The threats to pieces of infrastructure such as Tokamak illustrate the possible scope of their impact. Losing air cooling there will not result in a nuclear explosion, but equipment will go into shutdown. Now, any activity that uses cold water from the depths of the lake is at risk. Drinking water in Geneva and Lausanne is potentially threatened because the pumping and filtration systems are in the quagga zone. The airport \u2013 which uses the same water cooling system as the university \u2013 has also been hit. \u201cAll of them have this issue around the lake; there is no exception,\u201d says Dupanier.<\/p>\n Every spot is taken. Instead of seeing sand you see quagga musselsBastiaan Ibelings<\/p>\n The only way for EPFL and the University of Lausanne to protect their pipes is to build a new closed-loop, quagga-free cooling system. Construction will start in 2027 and should take five years. Dupanier says it will be a race against time to keep precious research going before the quaggas choke their systems any further.<\/p>\n \u2018It\u2019s a meadow of quaggas\u2019<\/p>\n From a floating research station on Lake Geneva, the lake looks as it always has, with snow-capped mountains tumbling into its dark waters. Over the past decade, however, ecologists know this lake has changed profoundly. \u201cThe surface is just a tiny part of the 300 metres below us,\u201d says Bastiaan Ibelings, a professor in ecology at the University of Geneva.<\/p>\n To illustrate the extent of the changes, technicians pull a chain up from the depths. It is encrusted in quagga mussels, like diamonds on gaudy costume jewellery. The base of the food chain that feeds this entire ecosystem has completely changed: snails, shrimps and native mussels that you might have found previously are nowhere to be seen. Even after 100 metres of chain, quaggas are still being hauled out of the water.<\/p>\n \u201cIt is too late for this lake,\u201d says Ibelings. \u201cIt\u2019s like a meadow of quaggas down there. Every spot is taken. Instead of seeing sand you see quagga mussels.\u201d<\/p>\n In Lake Geneva the molluscs have reached a record-breaking depth of 250 metres \u2013 a pitch-dark environment where there is almost no oxygen, home to scant life other than microbes. Their ability to survive where other species can\u2019t, means they grow uncontrollably in Alpine lakes.<\/p>\n For a long time, the invasion was not very visible to the public, says Ibelings, but now people are noticing something is not right. Dead mussels wash up on beaches, and people can\u2019t walk barefoot because they cut themselves. Recreational boaters have to scrape them off their craft every few months. Crayfish are covered in mussels and dying because they can\u2019t move.<\/p>\n 100% of samples<\/p>\n Quaggas originate from the Ponto-Caspian region of the Black Sea and were spread around the world via shipping routes<\/a>. They invaded the US\u2019s Great Lakes in 1989 and are now the dominant life form, making up more than 99%<\/a> of all invertebrate biomass in some lakes.<\/p>\n In the US, they have driven a collapse in the region\u2019s fish populations, with lawmakers warning they will need $500m (\u00a3375m) in federal funding<\/a> to address the issue. Great Lake shipwrecks \u2013 preserved in pristine condition for more than 100 years \u2013 are now coated in quaggas<\/a>.<\/p>\n This week, they were detected in Northern Ireland for the first time, with the country\u2019s environment minister, Andrew Muir, warning that \u201cincreased vigilance and surveillance\u201d was critical.<\/p>\n The mussels were first detected in Switzerland in 2014. The highest density was found in Lake Geneva, with an average of 4,000 quagga mussels a square metre across the whole lake. In some places there were more than 35,000 a square metre. In 2022, researchers found 98.9% of samples were quagga mussels, and in a 2024<\/a> survey, they exclusively scooped up quagga mussels \u2013 nothing else. \u201cQuaggas were 100% of samples,\u201d says Salom\u00e9 Boudet, a PhD student at the University of Geneva, who led the study. Mussel biomass in Lake Geneva is now comparable to what has been found in the Great Lakes, researchers say.<\/p>\n Globally, invasive species such as these are one of the five main drivers of biodiversity decline. The ecological knock-on effects in Swiss lakes will play out in the coming years.<\/p>\n \u2018Going back is a fairytale\u2019<\/p>\n Each mussel can filter up to two litres of water<\/a> a day, feeding primarily on phytoplankton, which forms the basis of the lake food chain. Tiny creatures such as water flea feed on phytoplankton, and then fish feed on the water flea. When the base of the chain disappears, it has cascading impacts on the entire food web, and potentially severe impacts on the livelihood of the 120 professional fishers working on Lake Geneva.<\/p>\n The filtering activity of quaggas also results in the water being clearer, which means light penetrates deeper. Like climate breakdown, this can lead to warmer water reaching deeper, with knock-on effects including an increase in toxic blue-green algal blooms. Previously, cold air from the atmosphere created lake currents, resulting in the mixing of water, but this hasn\u2019t happened since 2012.<\/p>\n Once quagga mussels are in a lake there is nothing you can do, other than stop them colonising other lakes by cleaning boats and fishing equipment.<\/p>\n After thousands of years of stability, Lake Geneva is undergoing a period of huge and irreversible change in the space of just a decade. In the US lakes, there are no signs of quagga populations falling after 30 years of colonisation.<\/p>\n Ibelings says: \u201cGoing back is a fairytale, because of quagga mussels and climate change. We cannot control either, and I don\u2019t think they will go away. We need to understand what they are doing to the lake.\u201d<\/p>\n In the future it is possible that nature will evolve, and some fish may adapt to eat quagga mussels, but ecologists say Lake Geneva will never be the same. \u201cWe need to accept at some point, whatever is there \u2013 this is a different lake, now,\u201d says Ibelings.<\/p>\n Find more age of extinction coverage here<\/a>, and follow the biodiversity reporters Phoebe Weston<\/a> and Patrick Greenfield<\/a> in the Guardian app for more nature coverage<\/p>\n","protected":false},"excerpt":{"rendered":"Like cholesterol clogging up an artery, it took just a couple of years for the quagga mussels to…\n","protected":false},"author":2,"featured_media":355475,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[43,44,41,39,42,40],"class_list":{"0":"post-355474","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-headlines","8":"tag-headlines","9":"tag-news","10":"tag-top-news","11":"tag-top-stories","12":"tag-topnews","13":"tag-topstories"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/355474","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/comments?post=355474"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/posts\/355474\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media\/355475"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/media?parent=355474"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/categories?post=355474"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/au\/wp-json\/wp\/v2\/tags?post=355474"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"The](\"https:\/\/www.newsbeep.com\/au\/wp-content\/uploads\/2025\/12\/384.jpg\")
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