The Hawaiian people practiced aquaculture through development of fish ponds, the most advanced fish husbandry among the original peoples of the Pacific. While other cultures in places like Egypt and China also used the practice, Hawaii’s aquaculture was very advanced considering the much smaller size of the area compared to others before it. These fishponds were typically shallow areas of a reef flat surrounded by a low lava rock wall built out from the shore. Several species of edible fish thrive in such ponds, and Hawaiians developed methods to make them easy to catch.
The Aachtopf is Germany's biggest karst spring, south of the western end of the Swabian Jura near the town of Aach. It produces an average of 8,500 litres per second. Most of the water stems from the River Danube where it disappears underground at the Danube Sinkhole, 12 kilometres (7.5 mi) north near Immendingen and about 14 kilometres (8.7 mi) north near Fridingen. The cave system has been explored since the 1960s, but as of 2020 only a small part has been discovered due to a large blockage after a few hundred metres.
Cat Island is located in central Bahamas, and is one of its districts. Cat Island also has the nation's highest point, Mount Alvernia. It rises to 63 metres (207 ft) and is topped by a monastery called The Hermitage. This assembly of buildings was erected by the Franciscan "Brother Jerome".
Guadalupe Island is a volcanic island located 241 kilometres off the western coast of Mexico's Baja California Peninsula and about 400 km (200 nmi) southwest of the city of Ensenada in the state of Baja California, in the Pacific Ocean. The various volcanoes are extinct or dormant. In 2005 Guadalupe Island and its surrounding waters and islets were declared a biosphere reserve to restore its vegetation and to protect its population of marine mammals and birds. The island is a popular destination for great white shark cage diving. Guadalupe Island is inhabited only by scientists, military personnel operating a weather station, and a small group of seasonal fishermen. The island is mostly arid and has very little surface water.
The Lost City Hydrothermal Field, often referred to simply as Lost City, is an area of marine alkaline hydrothermal vents located on the Atlantis Massif at the intersection between the Mid-Atlantic Ridge and the Atlantis Transform Fault, in the Atlantic Ocean. It is a long-lived site of active and inactive ultramafic-hosted serpentinization, abiotically producing many simple molecules such as methane and hydrogen which are fundamental to microbial life. As such it has generated scientific interest as a prime location for investigating the origin of life on Earth and other planets similar to it.
Jellyfish Lake is a marine lake located on Eil Malk island in Palau. Eil Malk is part of the Rock Islands, a group of small, rocky, mostly uninhabited islands in Palau's Southern Lagoon, between Koror and Peleliu. There are about 70 other marine lakes located throughout the Rock Islands. Millions of golden jellyfish migrate horizontally across the lake daily.
A blue hole is a large marine cavern or sinkhole, which is open to the surface and has developed in a bank or island composed of a carbonate bedrock. Blue holes typically contain tidally influenced water of fresh, marine, or mixed chemistry. They extend below sea level for most of their depth and may provide access to submerged cave passages. Well-known examples are the Dragon Hole and, in the Caribbean, the Great Blue Hole and Dean's Blue Hole.
Euryhaline organisms are able to adapt to a wide range of salinities. An example of a euryhaline fish is the short-finned molly, Poecilia sphenops, which can live in fresh water, brackish water, or salt water.
The Aquarium of Western Australia (AQWA) is a privately owned aquarium in Hillarys, Western Australia. Located approximately 20 km (12 mi) north-west of Perth City, it is a popular attraction for tourists and locals alike.
The Derawan Islands are in the province of East Kalimantan in Indonesia. They consist of 31 islands, most well known among these are the islands of Derawan, Kakaban, Maratua, and Sangalaki. There are also numerous submerged reefs and islets. They are located in the Sulawesi Sea, on the coastal shelf of East Kalimantan. The islands are part of the Berau Regency.
Botn is an inland fjord in the Rissa area of the municipality of Indre Fosen in Trøndelag county, Norway. It flows through a short, small river into the Sundsbukta, a small bay off the Trondheimsfjorden. The village of Årnset lies on the north shore of Botn.
Raja Ampat, or the Four Kings, is an archipelago located off of the northwest tip of Bird's Head Peninsula, Southwest Papua province, Indonesia. It comprises over 1,500 small islands, cays, and shoals around the four main islands of Misool, Salawati, Batanta, and Waigeo, and the smaller island of Kofiau.
Bay of Angra is a natural bay within the coastal extent of the municipality of Angra do Heroísmo, on the Portuguese island of Terceira in the archipelago of the Azores. Within an average depth of 40 metres (130 ft), the bay has been of historical importance to the island; since the 15th century, it was a port-of-call for returning merchant shipping from the East Indies and Brazil, laden with gold, silver, porcelain, spices, rare woods, and other goods. These ships would anchor in the Bay of Angra until supported by armed escorts, which would accompany the ships on the rest of their voyage to Portugal. The Bay at Angra provided shelter from northern and northwestern winds; only storms originating to the south or southeast, posed a threat. Nonetheless, the Bay is the final resting-place of several ships affected by the adverse winds: local archives and a rich oral tradition support the foundering of many ships against the leeward shore.
The Maldives, officially the Republic of Maldives, is a small archipelagic state in South Asia. It lies in the Indian Ocean southwest of Sri Lanka and India, about 700 kilometres (430 mi) from the Asian continent's mainland. The chain of 26 atolls stretches across the Equator from Ihavandhippolhu Atoll in the north to Addu Atoll in the south. The land area is roughly 298 square kilometres. Malé is the capital.
A marine lake is a lake situated very close to the sea, which has a connection to this sea, via tunnels or cracks in the soil. Marine lakes are fed with seawater but are usually also fed with rainwater, meaning that the salt content of the water is usually lower. The measure of salt greatly depends on the size of the tunnel or crack connecting it to the sea.
Darwin's Arch was a natural rock arch feature to the south-east of Darwin Island in the Galápagos Archipelago in the Pacific Ocean, and is now a pillar formation. The arch sat on an irregularly shaped, rocky, submerged plateau, nicknamed "the theatre". The arch collapsed into the sea on 17 May 2021 from natural erosion.
Piopiotahi Marine Reserve is a marine reserve covering an area of 690 hectares in the Milford Sound / Piopiotahi, in Fiordland on New Zealand's South Island. It was established in 1993 and is administered by the Department of Conservation.
Cave diving is underwater diving in water-filled caves. The equipment used varies depending on the circumstances, and ranges from breath hold to surface supplied, but almost all cave diving is done using scuba equipment, often in specialised configurations with redundancies such as sidemount or backmounted twinset. Recreational cave diving is generally considered to be a type of technical diving due to the lack of a free surface during large parts of the dive, and often involves planned decompression stops. A distinction is made by recreational diver training agencies between cave diving and cavern diving, where cavern diving is deemed to be diving in those parts of a cave where the exit to open water can be seen by natural light. An arbitrary distance limit to the open water surface may also be specified. Despite the risks, water-filled caves attract scuba divers, cavers, and speleologists due to their often unexplored nature, and present divers with a technical diving challenge.
An anchialine system is a landlocked body of water with a subterranean connection to the ocean. Depending on its formation, these systems can exist in one of two primary forms: pools or caves. The primary differentiating characteristics between pools and caves is the availability of light; cave systems are generally aphotic while pools are euphotic. The difference in light availability has a large influence on the biology of a given system. Anchialine systems are a feature of coastal aquifers which are density stratified, with water near the surface being fresh or brackish, and saline water intruding from the coast at depth. Depending on the site, it is sometimes possible to access the deeper saline water directly in the anchialine pool, or sometimes it may be accessible by cave diving.
