Overfishing happens when fish and other aquatic animals are caught from water bodies faster than they can reproduce and grow back. This leads to fewer fish in those areas over time. Overfishing can occur in any water environment, such as ponds, rivers, lakes, and oceans.
A sustainable fishery is one where fish are caught at a rate that keeps their population stable over time. This means fishing practices do not cause the number of fish to drop. Sustainability in fisheries uses both scientific knowledge, like how fish populations grow and change, and practical methods, such as setting limits on how much each fisher can catch.
Salmon are fish that live in freshwater streams as young fish and later move to the ocean as adults. They lay their eggs in clean, cool streams with stable gravel beds, where their young grow. These streams must have enough water flow, good water quality, and features like deep pools, shallow fast-moving areas, fallen trees, and plants along the stream banks that provide shade, food, and protection.
Dam removal is the process of taking down a dam to allow water to flow freely in a river. People consider whether the negative effects of dams are greater than their benefits when deciding to remove them. Dams provide benefits such as electricity generation, flood control, irrigation for crops, and helping boats travel along rivers.
Flood management or flood control are ways to reduce or stop the harmful effects of flood water. Flooding can happen because of natural causes, like heavy rain upstream, or because of human actions that change water systems and how water flows. Flood management methods can be structural, which means they use physical barriers, or non-structural, which do not.
A riparian zone, or riparian area, is the area where land meets a river or stream. In some places, other terms like riparian buffer zone, riparian corridor, and riparian strip are used to describe these areas. The word “riparian” comes from the Latin word “ripa,” which means “river bank.” Riparian zones are areas where land and water meet.
An estuary is a partly enclosed coastal area where freshwater from rivers or streams mixes with saltwater from the ocean. Estuaries act as transition zones between rivers and the sea, and they are called ecotones, which are areas where different ecosystems meet. These areas are shaped by both ocean processes, like tides and waves, and river processes, such as the flow of freshwater and the movement of sediment.
Lake Sammamish (Lushootseed: sc̓ababš) is a freshwater lake located 8 miles (13 km) east of Seattle in King County, Washington, United States. The lake is 7 miles (11 km) long and 1.5 miles (2 km) wide. Its maximum depth is 105 feet (32 m), and its surface area is 8 square miles (21 km²).
Freshwater ecosystems are a type of Earth’s aquatic ecosystems that include living things in bodies of water such as lakes, ponds, rivers, streams, springs, bogs, and wetlands. These ecosystems differ from marine ecosystems, which have much saltier water. Freshwater habitats can be grouped based on factors like temperature, how much light reaches the water, the amount of nutrients, and the presence of plants.
Water scarcity is when a region does not have enough fresh water to meet its needs. There are two types of water scarcity: physical and economic. Physical water scarcity happens when there is not enough water available to meet all needs, including water needed for ecosystems to stay healthy.