Lakes and ponds, on the other hand, can exchange nutrients in a seasonal cycle. These waterways also enable migrating species, like salmon, to bring nutrients from the ocean to upstream freshwater ecosystems. The ecosystems in rivers and streams, for example, bring salts and nutrients from the mountains to lakes, ponds, and wetlands at lower elevations, and eventually they bring those nutrients to the ocean. This knowledge can help the researchers know when a freshwater ecosystem is healthy and when it may be in danger.įreshwater ecosystems naturally share resources between habitats. Limnologists want to learn what creatures live in an ecosystem and how they interact with each other through the ecosystem’s food web, as well as how they interact with their environment. Scientists who study freshwater ecosystems are called limnologists. She was one of the first scientists ever to describe the biodiversity in these Icelandic fissure ecosystems. Wearing scuba gear, Olafsdóttir drops into the water and collects biological samples, recording notes about the species of fish, crustaceans, algae, and other microbes that she finds. The crystal blue water in these fissures is barely above freezing temperature. These fissures are large cracks, which are caused by the tectonic plates underneath the country shifting and pulling the bedrock apart. On the volcanic island nation of Iceland, explorer Jónína Herdís Ólafsdóttir studies freshwater ecosystems that develop from groundwater seeping into fissures. The top surface of an aquifer is called the water table, and this is the depth where wells are drilled to bring freshwater into cities and homes. More than half of all freshwater on our planet seeps through soil and between rocks to form aquifers that are filled with groundwater. But freshwater can be found in less-obvious places too. When this vapor rises, it leaves salts and other contaminants behind and becomes “fresh.” The water vapor collects in drifting clouds that eventually release the water back to Earth in the form of rain or snow.Īfter freshwater reaches the ground through precipitation, it flows downhill across a landscape called the watershed to lakes, ponds, rivers, streams, and wetlands. For these reasons, freshwater ecosystems are a precious resource.įreshwater starts out as water vapor that has evaporated from the surface of oceans, lakes, and other bodies of water. Less than three percent of our planet’s water is freshwater, and less than half of that is available as a liquid the rest is locked away as ice in polar caps and glaciers. The plants, animals, microbes, rocks, soil, sunlight, and water found in and around this valuable resource are all part of what is called a freshwater ecosystem. Every living thing on Earth needs water to survive, but more than 100,000 species, including our own, need a special kind of water that can only be found in certain places and is in very rare supply: freshwater.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |