Final answer:
Freshwater ecosystems, representing only 1.8 percent of Earth's surface, are essential for biodiversity, providing habitat for many species despite being a small fraction of the planet's area.
Step-by-step explanation:
Freshwater ecosystems cover less than 1.8 percent of Earth's surface yet support a significant portion of global biodiversity. These ecosystems encompass diverse habitats such as lakes, rivers, streams, and springs, and are home to a wide array of life including fish, amphibians, reptiles, insects, phytoplankton, fungi, and bacteria.
Despite their limited coverage of the Earth's surface, freshwater ecosystems are biologically rich and are particularly important for the species they support. Moreover, only 2.5 percent of water on Earth is freshwater, and less than 1 percent of that is easily accessible to living things, highlighting the precious nature of these habitats.