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Shark Cage
Shark cage diving is underwater diving or snorkeling where the observer remains inside a protective cage designed to prevent sharks from making contact with the divers. Shark cage diving is used for scientific observation, underwater cinematography, and as a tourist activity. Sharks may be attracted to the vicinity of the cage by the use of bait in a procedure known as ''chumming''. This procedure has attracted controversy due to claims that it could potentially alter the natural behaviour of sharks in the vicinity of swimmers. Similar cages are also used as a protective measure for divers working in waters where potentially dangerous shark species are present. In this application, the shark-proof cage may be used as a refuge, or as a diving stage during descent and ascent, particularly during staged decompression practice, decompression where the divers may be vulnerable while constrained to a specific depth in mid-water for several minutes. In other applications, a mobile cage m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sharks Outside Cage
Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the Division (taxonomy), division Selachii and are the sister group to the Batoidea, Batomorphi (Batoidea, rays and skate (fish), skates). Some sources extend the term "shark" as an informal category including Extinction, extinct members of Chondrichthyes (cartilaginous fish) with a shark-like morphology, such as hybodonts. Shark-like chondrichthyans such as ''Cladoselache'' and ''Doliodus'' first appeared in the Devonian Period (419–359 million years), though some fossilized chondrichthyan-like scales are as old as the Ordovician, Late Ordovician (458–444 million years ago). The earliest confirmed modern sharks (Selachii) are known from the Early Jurassic around , with the oldest known member being ''Agaleus'', though records of true shar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Port Lincoln Times
The ''Port Lincoln Times'' is a newspaper published weekly in Port Lincoln, South Australia. It was first printed in August 1927, and has been published continuously ever since. It was later sold to Rural Press, previously owned by Fairfax Media, but now an Australian media company trading as Australian Community Media. History The origins of the ''Port Lincoln Times'' began when the '' Recorder'' in Port Pirie was taken over by Mrs R.L. McGregor and her two sons. McGregor had worked under David Drysdale at the '' Port Augusta Dispatch'' and claims she was instrumental in suggesting that he start a newspaper in Port Lincoln. In 1925, she was approached by another former ''Dispatch'' employee, Maurice Hill, to sell the ''Recorder'', but she refused, and as a result, Hill, along with J.E. Edwards, founded the ''Port Lincoln Times.'' The ''Port Lincoln Times'' was first published on 5 August 1927, and unlike many newspapers of the time, it did not continue or subsume a previous pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marine Biology (journal)
''Marine Biology'' is a peer-reviewed scientific journal covering research on all aspects of marine biology. The journal was established in 1967 and is published monthly by Springer Science+Business Media. The editor-in-chief is Ulrich Sommer ( Helmholtz Centre for Ocean Research). According to the ''Journal Citation Reports'', the journal has a 2014 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a type of journal ranking. Journals with higher impact factor values are considered more prestigious or important within their field. The Impact Factor of a journa ... of 2.391. References External links * Biology journals Springer Science+Business Media academic journals English-language journals Academic journals established in 1967 Marine biology Monthly journals Hybrid open access journals {{biology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scarborough, Western Cape
Scarborough is a seaside town situated within the City of Cape Town on the Cape Peninsula in the Western Cape province of South Africa, situated at the edge of the Cape Point Nature Reserve. The town's boundary includes Scarborough Beach, which is popular with surfers. This town was designated as a conservation village in April 1996, defined as "a residential area of limited extent, surrounded by a conserved natural landscape, committed to reverse past environmental damage Environment most often refers to: __NOTOC__ * Natural environment, referring respectively to all living and non-living things occurring naturally and the physical and biological factors along with their chemical interactions that affect an organism ... and to avoid future environmental impacts". References External links Scarborough Conservation GroupCape Point Route ScarboroughScarborough Village {{Authority control Suburbs of Cape Town Surfing locations in South Africa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ragged-tooth Shark
The sand tiger shark (''Carcharias taurus''), grey/gray nurse shark (in Australia), spotted ragged-tooth shark (in South Africa), or blue-nurse sand tiger, is a species of shark that inhabits subtropical and temperate waters worldwide. It inhabits the continental shelf, from sandy shorelines (hence the name sand tiger shark) and submerged reefs to a depth of around . They dwell in the waters of Japan, Australia, South Africa, and the east coasts of North and South America. The sand tiger shark also inhabited the Mediterranean, however it was last seen there in 2003 and is presumed extirpated. Despite its common names, it is not closely related to either the tiger shark (''Galeocerdo cuvier'') or the nurse shark (''Ginglymostoma cirratum''). Despite its fearsome appearance and strong swimming ability, it is a relatively placid and slow-moving shark with no confirmed human fatalities. This species has a sharp, pointy head, and a bulky body. The sand tiger's length can reach but is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shark Baiting
Shark cage diving is underwater diving or snorkeling where the observer remains inside a protective cage designed to prevent sharks from making contact with the divers. Shark cage diving is used for scientific observation, underwater cinematography, and as a tourist activity. Sharks may be attracted to the vicinity of the cage by the use of bait in a procedure known as ''chumming''. This procedure has attracted controversy due to claims that it could potentially alter the natural behaviour of sharks in the vicinity of swimmers. Similar cages are also used as a protective measure for divers working in waters where potentially dangerous shark species are present. In this application, the shark-proof cage may be used as a refuge, or as a diving stage during descent and ascent, particularly during staged decompression where the divers may be vulnerable while constrained to a specific depth in mid-water for several minutes. In other applications, a mobile cage may be carried by the di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neptune Islands
The Neptune Islands consist of two groups of islands located close to the entrance to Spencer Gulf in South Australia. They are well known as a venue for great white shark tourism. Description The Neptune Islands consists of two groups of islands, the North Neptune Islands and the South Neptune Islands. These both sit on the southern aspect of the Australasian continental shelf separated by a distance of . The North Neptune Islands which are south south-east from the mainland at Cape Catastrophe, consist of a large island of height and a small islet of height located from the main island's north-east point with a combined area of . The South Neptune Islands which are south-south-east from the mainland at Cape Catastrophe are more evenly portioned in height with the northern island being high and the southern island (also known as Lighthouse Island) rising to . The Southern group has an area of . A third feature associated with the overall island group is an outcrop of roc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Port Lincoln
Port Lincoln is a city on the Lower Eyre Peninsula in the Australian states and territories of Australia, state of South Australia. Known as Galinyala by the traditional owners, the Barngarla people, it is situated on the shore of Boston Bay, which opens eastward into Spencer Gulf. It is the largest city in the West Coast region, and is located approximately from the state's capital city of Adelaide ( by road). In June 2019 Port Lincoln had an estimated population of 26,418, having grown at an average annual rate of 0.55% year-on-year over the preceding five years. The city is reputed to have the most millionaires per capita in Australia, as well as claiming to be Australia's "Seafood Capital". History and name The Eyre Peninsula has been home to Aboriginal Australians, Aboriginal people for over 40 thousand years, with the Barngarla people, Barngarla (eastern Eyre, including Port Lincoln), Nauo people, Nauo (south western Eyre), Wirangu language, Wirangu (north western Eyre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australian National Maritime Museum
The Australian National Maritime Museum (ANMM) is a Australian government, federally operated maritime museum in Darling Harbour, Sydney. After considering the idea of establishing a maritime museum, the federal government announced that a national maritime museum would be constructed at Darling Harbour, tied into the Government of New South Wales, New South Wales state government's redevelopment of the area for the Australian bicentenary in 1988. The museum building was designed by Philip Cox, and although an opening date of 1988 was initially set, construction delays, cost overruns, and disagreements between the state and federal governments over funding responsibility pushed the opening to 1991. One of six museums directly operated by the federal government, the ANMM is the only one located outside of the Australian Capital Territory. The museum is structured around seven main galleries, focusing on the relationships between Indigenous Australians and the sea, the navigation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutral Buoyancy
Neutral buoyancy occurs when an object's average density is equal to the density of the fluid in which it is immersed, resulting in the buoyant force balancing the force of gravity that would otherwise cause the object to sink (if the body's density is greater than the density of the fluid in which it is immersed) or rise (if it is less). An object that has neutral buoyancy will neither sink nor rise. In scuba diving, the ability to maintain neutral buoyancy through controlled breathing, accurate weighting, and management of the buoyancy compensator is an important skill. A scuba diver maintains neutral buoyancy by continuous correction, usually by controlled breathing, as neutral buoyancy is an unstable condition for a compressible object in a liquid. History The mathematician Archimedes discovered much of how buoyancy works more than 2000 years ago. In his research, Archimedes discovered that an object is buoyed up by a force equal to the weight of the water displaced by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Propeller
A propeller (often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon a working fluid such as water or air. Propellers are used to pump fluid through a pipe or duct, or to create thrust to propel a boat through water or an aircraft through air. The blades are shaped so that their rotational motion through the fluid causes a pressure difference between the two surfaces of the blade by Bernoulli's principle which exerts force on the fluid. Most marine propellers are screw propellers with helical blades rotating on a propeller shaft (ship), propeller shaft with an approximately horizontal axis. History Early developments The principle employed in using a screw propeller is derived from stern sculling. In sculling, a single blade is moved through an arc, from side to side taking care to keep presenting the blade to the wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abstract (summary)
An abstract is a brief summary of a research article, thesis, review, conference proceeding, or any in-depth analysis of a particular subject and is often used to help the reader quickly ascertain the paper's purpose. When used, an abstract always appears at the beginning of a manuscript or typescript, acting as the point-of-entry for any given academic paper or patent application. Abstracting and indexing services for various academic disciplines are aimed at compiling a body of literature for that particular subject. The terms ''précis'' or ''synopsis'' are used in some publications to refer to the same thing that other publications might call an "abstract". In management reports, an '' executive summary'' usually contains more information (and often more sensitive information) than the abstract does. Purpose and limitations Academic literature uses the abstract to succinctly communicate complex research. An abstract may act as a stand-alone entity instead of a full paper. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
