Human activities increase extinction risks for freshwater species worldwide

In a new study, researchers analyzed a variety of anthropogenic threats to global freshwater biodiversity.(CN) — Although freshwater ecosystems constitute less than 4% of Earth’s surface area, nearly a third of the planet’s vertebrate life forms call these regions home. This makes it clear that wetlands, riparian areas and similar biomes hold incredible ecological importance. Yet when it comes to conservation efforts, freshwater systems don’t always get the same attention as their terrestrial counterparts. In a study published Thursday in the journal Science, researchers mapped global threats to freshwater biodiversity, aiming to compel governments, environmental groups and citizens internationally to take action “by showing where freshwater species are under pressure and which threats need attention,” biologist Christophe Brabant said.Brabant and a team at McGill University in Montreal, Canada, took over 21,000 freshwater species into account while creating a geographic analysis of 45 kinds of threats faced across that worldwide population. Some threats are more singular, while others overlap. Most are manmade.In much of South America, for example, the unchecked impacts of agriculture and aquaculture top the list of risks. In the eastern U.S., residential and commercial development combine with excess human emissions — an environmentally deleterious double-whammy.Europe and northwest Africa stood out to researchers as areas of most concern, with the former “most strongly affected by pollution from urban, agricultural, and industrial sources” and the latter by “a combination of pollution, damming, and intensive water use.”In less populated regions like Siberia and northern Canada, threat levels were mild in comparison.Brabant told Courthouse News that European species like the fire salamander and European eel experience threats from agricultural activity. However, urbanization and pollution threaten the critically endangered eel more imminently, while the salamander struggles to survive manmade habitat destruction and competition with invasive species.The researchers found that freshwater species as a whole “experience higher threat impacts than species restricted to terrestrial environments, on average.”Brabant brought up United Nations conservation guidelines that he said must be adhered to if these anthropogenic outcomes are to be prevented or reversed. “The [2022] Kunming–Montreal Global Biodiversity Framework already sets commitments to reduce pollution, manage agriculture more sustainably, and conserve and restore ecosystems,” he said. “COP17, currently taking place in Armenia, marks the first global review of progress in implementing that framework. It is an important opportunity to ensure these commitments translate into meaningful action for freshwater species.”“Ultimately, conservation action happens locally," Brabant added. “For agricultural runoff, this could mean working with farmers to reduce fertilizer and pesticide runoff, restore vegetation along riverbanks and protect wetlands. For dams, it could involve adjusting operations to maintain seasonal flows that species depend on, protecting connected river habitats and removing obsolete barriers where appropriate. These actions also need coordination across river basins, because activities upstream can affect species far downstream.”A less biodiverse world of water is a less healthy one, Brabant concluded. “Healthy freshwater ecosystems are essential to human well-being. They provide water and food, support livelihoods, and help protect communities from flooding,” he said. “Decisions about land use therefore need to consider their long-term effects on these ecosystems and the people who depend on them.”Subscribe to our free newslettersOur weekly newsletter Closing Arguments offers the latest about ongoing trials, major litigation and rulings in courthouses around the U.S. and the world, while the monthly Under the Lights dishes the legal dirt from Hollywood, sports, Big Tech and the arts.Additional Reads