Lagoon in the context of "Syvash"

Marine life, sea life or ocean life is the collective ecological communities that encompass all aquatic animals, plants, algae, fungi, protists, single-celled microorganisms and associated viruses living in the saline water of marine habitats, either the sea water of marginal seas and oceans, or the brackish water of coastal wetlands, lagoons, estuaries and inland seas. As of 2023, more than 242,000 marine species have been documented, and perhaps two million marine species are yet to be documented. An average of 2,332 new species per year are being described. Marine life is studied scientifically in both marine biology and in biological oceanography.

By volume, oceans provide about 90% of the living space on Earth, and served as the cradle of life and vital biotic sanctuaries throughout Earth's geological history. The earliest known life forms evolved as anaerobic prokaryotes (archaea and bacteria) in the Archean oceans around the deep sea hydrothermal vents, before photoautotrophs appeared and allowed the microbial mats to expand into shallow water marine environments. The Great Oxygenation Event of the early Proterozoic significantly altered the marine chemistry, which likely caused a widespread anaerobe extinction event but also led to the evolution of eukaryotes through symbiogenesis between surviving anaerobes and aerobes. Complex life eventually arose out of marine eukaryotes during the Neoproterozoic, and which culminated in a large evolutionary radiation event of mostly sessile macrofaunae known as the Avalon Explosion. This was followed in the early Phanerozoic by a more prominent radiation event known as the Cambrian Explosion, where actively moving eumetazoan became prevalent. These marine life also expanded into fresh waters, where fungi and green algae that were washed ashore onto riparian areas started to take hold later during the Ordovician before rapidly expanding inland during the Silurian and Devonian, paving the way for terrestrial ecosystems to develop.

An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments and are an example of an ecotone. Estuaries are subject both to marine influences such as tides, waves, and the influx of saline water, and to fluvial influences such as flows of freshwater and sediment. The mixing of seawater and freshwater provides high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world.

Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are typically classified according to their geomorphological features or to water-circulation patterns. They can have many different names, such as bays, harbors, lagoons, inlets, or sounds, although some of these water bodies do not strictly meet the above definition of an estuary and could be fully saline.

The Gulf of Drin or Bay of Drin (Albanian: Gjiri i Drinit or Pellgu i Drinit) is an ocean basin of the Adriatic Sea within the Mediterranean Sea along the northern coast of Albania. Roughly scythe-shaped, it extends immediately from the Delta of the Buna in the north, across the port city of Shëngjin, to the Cape of Rodon in the south. The shoreline of the gulf is a shallow combination of sandy beaches, sand dunes, capes, salty and fresh water wetlands, estuaries, pine and coastal forests, reed beds and coastal meadows.

The shoreline of the gulf has a length of approximately 60 kilometres and is dotted with cliffs and beaches fed by fluvial imputes. The region is drained by numerous rivers and has formed a characteristic ecosystem and biodiversity. It is named after the Drin River that runs through a mountainous area towards the coast, however, the Ishëm and Mat also drain into the gulf. In consideration to the flat landscape, the gulf's shoreline are dotted with extensive wetlands and lagoons that continuously change in size and shape.

Butrint Lagoon (Albanian: Liqeni i Butrintit) is a salt lagoon south of Saranda, Albania, located in direct proximity of the Ionian Sea. It is surrounded by dense forested hills, rocky coast and complemented by saltwater and freshwater marshlands. The lake has a length of 7.1 km (4.4 mi) and a width of 3.3 km (2.1 mi), with a surface area of 16 km (6.2 sq mi). The maximum depth of the lake is 24.4 m (80 ft). It is shaped like a giant footprint, pointing north. At its south, the Vivari Channel connects the lagoon to the sea.

Ölüdeniz (literally "Dead Sea", due to its calm waters even during storms; official translation: Blue Lagoon) is a town of the municipality and district of Fethiye, Muğla Province, Turkey. Its population is 6,132 (2022). Before the 2013 reorganisation, it was a town (belde). It is a beach resort on the Turkish Riviera, at the conjunction point of the Aegean and Mediterranean seas. It is located 14 km (9 mi) south of Fethiye, near Mount Babadağ.

It has a sandy bay at the mouth of Ölüdeniz, on a blue lagoon. The beach itself is a pebble beach. The lagoon is a national nature reserve and construction is strictly prohibited. The seawater of Ölüdeniz is famous for its shades of turquoise and aquamarine, while its beach is an official Blue Flag beach.

A lake is often a naturally occurring, relatively large and fixed body of water on or near the Earth's surface. It is localized in a basin or interconnected basins surrounded by dry land. Lakes lie completely on land and are separate from the ocean, although they may be connected with the ocean by rivers. Lakes, like other bodies of water, are part of the water cycle, the processes by which water moves around the Earth. Most lakes are fresh water and account for almost all the world's surface freshwater, but some are salt lakes with salinities even higher than that of seawater. Lakes vary significantly in surface area and volume of water.

Lakes are typically larger and deeper than ponds, which are also water-filled basins on land, although there are no official definitions or scientific criteria distinguishing the two. Lakes are also distinct from lagoons, which are generally shallow tidal pools dammed by sandbars or other material at coastal regions of oceans or large lakes. Most lakes are fed by springs, and both fed and drained by creeks and rivers, but some lakes are endorheic without any outflow, while volcanic lakes are filled directly by precipitation runoffs and do not have any inflow streams.

In geography, a sound is a smaller body of water usually connected to a sea or an ocean. A sound may be an inlet that is deeper than a bight and wider than a fjord; or a narrow sea channel or an ocean channel between two land masses, such as a strait; or also a lagoon between a barrier island and the mainland.

Marine ecosystems are the largest of Earth's aquatic ecosystems and exist in waters that have a high salt content. These systems contrast with freshwater ecosystems, which have a lower salt content. Marine waters cover more than 70% of the surface of the Earth and account for more than 97% of Earth's water supply and 90% of habitable space on Earth. Seawater has an average salinity of 35 parts per thousand of water. Actual salinity varies among different marine ecosystems. Marine ecosystems can be divided into many zones depending upon water depth and shoreline features. The oceanic zone is the vast open part of the ocean where animals such as whales, sharks, and tuna live. The benthic zone consists of substrates below water where many invertebrates live. The intertidal zone is the area between high and low tides. Other near-shore (neritic) zones can include mudflats, seagrass meadows, mangroves, rocky intertidal systems, salt marshes, coral reefs, kelp forests and lagoons. In the deep water, hydrothermal vents may occur where chemosynthetic sulfur bacteria form the base of the food web.

Marine ecosystems are characterized by the biological community of organisms that they are associated with and their physical environment. Classes of organisms found in marine ecosystems include brown algae, dinoflagellates, corals, cephalopods, echinoderms, and sharks.