The current extinction rate for terrestrial organisms is estimated to be between 100 and 1,000 times higher than the background extinction rate, which is the average rate of extinction over long periods of geological time. This alarming acceleration in extinction rates is primarily driven by human activities such as habitat destruction, climate change, overexploitation, pollution, and the introduction of invasive species.
A comprehensive study published in 2019 assessed extinction risks for a large sample of plant and animal species worldwide. They found that approximately 29% of all assessed mammal species, 13% of bird species, 41% of amphibians, 33% of reef-building corals, and 31% of cycads (a group of ancient seed plants) face extinction in the medium term.
Freshwater Organisms
Similar to terrestrial organisms, freshwater species are experiencing elevated extinction rates primarily due to anthropogenic factors. Habitat loss, water pollution, overfishing, and the proliferation of invasive species have severely impacted freshwater ecosystems, leading to increased threats to freshwater biodiversity.
The extinction rates of freshwater species are considerably higher compared to terrestrial species. One study suggests that vertebrate extinction rates in freshwaters may be over 4 times higher than those in terrestrial habitats, underscoring the critical conservation challenges within freshwater environments.
Freshwater fish, amphibians, and certain invertebrate groups suffer from disproportionately high extinction risks. Over 30% of freshwater fish and at least one-third of amphibian species assessed in global conservation assessments are threatened with extinction, highlighting the severity of freshwater biodiversity loss.