bays

A bay is a recessed coastal body of water connected to a larger sea or ocean, typically formed where land curves inward and provides shelter from prevailing waves. Bays usually have a wide, open mouth and a curved shoreline that encloses calmer waters inside, making them favorable for harbors and coastal settlements. The size and shape of bays vary, and the term is not applied consistently in every coastline feature.

Formation and related forms: Bays can form by differential erosion where softer rock wears away faster than surrounding headlands, by the flooding of river valleys (rias) as sea levels rise, or by glacial action that carves large inlets (fjords) which may be called bays in common usage. In geology, fjords and rias are closely related to bays but are typically distinguished by their origin and morphology. Some basins are estuarine, where freshwater from rivers mixes with seawater, producing productive environments.

Ecology and use: Bays often host rich ecosystems, including tidal flats, salt marshes or mangroves, and diverse fish and invertebrate communities. Their sheltered waters support commercial and recreational fishing, harbors, shipping, tourism, and other human activities. Environmental threats include sedimentation, pollution, invasive species, and sea-level rise.

Examples: San Francisco Bay, Chesapeake Bay, Tampa Bay, Delaware Bay, Bay of Biscay, Bay of Bengal, and the Bay of Fundy illustrate the geographic range of bays, from enclosed to more open coastlines.