Learn the Names for Bodies of Water

Definitions of Lakes, Rivers, Seas, Oceans, Bays, Streams, and More

Lake Michigan
Lake Michigan runs along the coast of Chicago, IL. Roman Boed / Flickr / CC BY 2.0

Water bodies are described by a plethora of different names in English: rivers, streams, ponds, bays, gulfs, and seas to name a few. Many of these terms' definitions overlap and thus become confusing when one attempts to pigeonhole a type of water body. A look at its characteristics is the place to start, though.

Flowing Water

Let's begin with the different forms of flowing water. The smallest water channels are often called brooks, and you can generally step across a brook. Creeks are often larger than brooks but may either be permanent or intermittent. Creeks are also sometimes known as streams, but the word "stream" is quite a generic term for any body of flowing water. Streams can be intermittent or permanent and can be on the surface of the earth, underground, or even within an ocean, such as the Gulf Stream.

A river is a large stream that flows over land. It is often a perennial water body and usually flows in a specific channel, with a considerable volume of water. The world's shortest river, the D River, in Oregon, is only 120 feet long and connects Devil's Lake directly to the Pacific Ocean.

Connections

Any lake or pond directly connected to a larger body of water can be called a lagoon, and a channel is a narrow sea between two land masses, such as the English Channel. The American South contains bayous, which are sluggish waterways that flow between swamps. Farm fields across the country may be surrounded by drainage ditches that flow runoff into creeks and streams.

Transitions

Wetlands are low-lying areas that are either seasonally or permanently filled with water, aquatic vegetation, and wildlife. They help prevent flooding by being a buffer between flowing water and land areas, serve as a filter, recharge groundwater supplies, and prevent erosion. Freshwater wetlands containing woods are swamps; their water level or permanency can change over time, between wet and dry years. Marshes can be found along rivers, ponds, lakes, and coasts and can have any type of water (fresh, salt, or brackish). Bogs develop as moss fills in a pond or lake. They contain a lot of peat and don't have groundwater coming in, relying on runoff and precipitation to exist. A fen is less acidic than a bog, still is fed by groundwater, and has more diversity among grasses and flowers. A slough is a swamp or shallow lake or wetland system that flows to larger bodies of water, commonly in an area where a river once flowed.

Areas, where oceans and freshwater rivers meet, are brackish water transitions known as estuaries. A marsh can be a part of an estuary.

Where Land Meets Water

Coves are the smallest indentations of land by a lake, sea, or ocean. A bay is larger than a cove and can refer to any wide indentation of the land. Larger than a bay is a gulf, which is usually a deep cut of the land, such as the Persian Gulf or the Gulf of California. Bays and gulfs can also be known as inlets. 

Water That's Surrounded

A pond is a small lake, most often in a natural depression. Like a stream, the word "lake" is quite a generic term—it refers to any accumulation of water surrounded by land—although lakes can often be of a considerable size. There's no specific size that denotes either a large pond or a small lake, but lakes generally are bigger than ponds. 

A very large lake that contains salt water is known as a sea (except the Sea of Galilee, which is actually a freshwater lake). A sea can also be attached to, or even part of, an ocean. For example, the Caspian Sea is a large saline lake surrounded by land, the Mediterranean Sea is attached to the Atlantic Ocean, and the Sargasso Sea is a portion of the Atlantic Ocean, surrounded by water.

The Largest Water Bodies

Oceans are the ultimate bodies of water on Earth and are the Atlantic, Pacific, Arctic, Indian, and Southern. The equator divides the Atlantic Ocean and Pacific Oceans into the North and South Atlantic Ocean and the North and South Pacific Ocean.