1.
Atlantic herring
–
Atlantic herring is a herring in the family Clupeidae. It is one of the most abundant fish species in the world, Atlantic herrings can be found on both sides of the Atlantic Ocean, congregating in large schools. They can grow up to 45 centimetres in length and weigh up to 1.1 kilograms and they feed on copepods, krill and small fish, while their natural predators are seals, whales, cod and other larger fish. The Atlantic herring fishery has long been an important part of the economy of New England and this is because the fish congregate relatively near to the coast in massive schools, notably in the cold waters of the semi-enclosed Gulf of Maine and Gulf of St. Lawrence. North Atlantic herring schools have been measured up to 4 cubic kilometres in size, Atlantic herring have a fusiform body. Gill rakers in their mouths filter incoming water, trapping any zooplankton and phytoplankton, Atlantic herring are in general fragile. They have large and delicate gill surfaces, and contact with foreign matter can strip away their large scales and they have retreated from many estuaries worldwide due to excess water pollution although in some estuaries that have been cleaned up, herring have returned. The presence of their larvae indicates cleaner and more–oxygenated waters, Atlantic herring can be found on both sides of the ocean. Although Atlantic herring are found in the waters surrounding the Arctic. The small-sized herring in the parts of the Baltic Sea. The Baltic herring has a name in many local languages and is popularly. For example, the Swedish dish surströmming is made from Baltic herring, herring-like fish are the most important fish group on the planet. They are also the most populous fish and they are the dominant converter of zooplankton into fish, consuming copepods, arrow worms chaetognatha, pelagic amphipods hyperiidae, mysids and krill in the pelagic zone. Conversely, they are a prey item or forage fish for higher trophic levels. The reasons for success is still enigmatic, one speculation attributes their dominance to the huge. Orca, cod, dolphins, porpoises, sharks, rockfish, seabird, whales, squid, sea lions, seals, tuna, salmon, herring are pelagic–prey includes copepods, amphipods like Hyperia spp. Atlantic herring can school in huge numbers, radakov estimated herring schools in the North Atlantic can occupy up to 4.8 cubic kilometres with fish densities between 0.5 and 1.0 fish/cubic metre. Thats several billion fish in one school, herring are amongst the most spectacular schoolers
Atlantic herring
Atlantic herring
–
Atlantic herring
Atlantic herring
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Clupea harengus in a barrel
Atlantic herring
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This article includes a
list of references, but its sources remain unclear because it has insufficient
inline citations. Please help to
improve this article by
introducing more precise citations. (April 2009)
2.
Forage fish
–
Forage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the chain on plankton. They include particularly fishes of the family Clupeidae, but also small fish, including halfbeaks, silversides, smelt such as capelin. Forage fish compensate for their size by forming schools. Some swim in synchronised grids with their mouths open so they can efficiently filter plankton and these schools can become immense shoals which move along coastlines and migrate across open oceans. The shoals are concentrated fuel resources for the marine predators. The ocean primary producers, mainly contained in plankton, produce energy from the sun and are the raw fuel for the ocean food webs. Forage fish transfer this energy by eating the plankton and becoming food themselves for the top predators, in this way, forage fish occupy the central positions in ocean and lake food webs. The fishing industry catches forage fish primarily for feeding to farmed animals, some fisheries scientists are expressing concern that this will affect the populations of predator fish that depend on them. Herrings are a preeminent forage fish, often marketed as sardines or pilchards, the term “forage fish” is a term used in fisheries, and is applied also to forage species that are not true fish, but play a significant role as prey for predators. Thus invertebrates such as squid and shrimp are also referred to as forage fish, even the tiny shrimp-like creatures called krill, small enough to be eaten by other forage fish, yet large enough to eat the same zooplankton as forage fish, are often classified as forage fish. Forage fish utilise the biomass of copepods, mysids and krill in the zone to become the dominant converters of the enormous ocean production of zooplankton. They are, in turn, central prey items for higher trophic levels, Forage fish may have achieved their dominance because of the way they live in huge, and often extremely fast cruising schools. Though forage fish are abundant, there are few species. There are more species of primary producers and apex predators in the ocean there are forage fish. Forage fish occupy central positions in the food webs. The position that a fish occupies in a web is called its trophic level
Forage fish
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These small
goldband fusiliers are typical forage fish. They swim in large schools for protection from larger predators.
Forage fish
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Ocean forage fish
Forage fish
Forage fish
3.
Clupeidae
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Clupeidae is a family of ray-finned fishes, comprising, for instance, the herrings, shads, sardines, hilsa, and menhadens. The clupeids include many of the most important food fishes in the world, clupeids are mostly marine forage fish, although a few species are found in fresh water. No species has scales on the head, and some are entirely scaleless, the lateral line is short or absent, and the teeth are unusually small where they are present at all. Clupeids typically feed on plankton, and range from 2 to 75 cm in length, the family arguably also contains the Sundasalangidae, a paedomorphic taxon first thought to be distinct salmoniform family but then found to be deeply nested in Clupeidae. In the fossil record date back to the early Paleogene. Clupeids spawn huge numbers of eggs near the surface of the water, after hatching, the larvae live among the plankton until they develop a swim bladder and transform into adults. These eggs and fry are not protected or tended to by parents, the adults typically live in large shoals, seeking protection from piscivorous predators such as birds, sharks and other predatory fish, tooth whales, marine mammals and jellyfish. The family currently comprises 54 genera and approximately 200 species
Clupeidae
Clupeidae
–
True herrings
Clupeidae
–
Marine
4.
Shoaling and schooling
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In biology, any group of fish that stay together for social reasons are shoaling, and if the group is swimming in the same direction in a coordinated manner, they are schooling. In common usage, the terms are used rather loosely. About one quarter of fish species shoal all their lives, Fish derive many benefits from shoaling behaviour including defence against predators, enhanced foraging success, and higher success in finding a mate. It is also likely that fish benefit from shoal membership through increased hydrodynamic efficiency, Fish use many traits to choose shoalmates. Generally they prefer larger shoals, shoalmates of their own species, shoalmates similar in size and appearance to themselves, healthy fish, the oddity effect posits that any shoal member that stands out in appearance will be preferentially targeted by predators. This may explain why fish prefer to shoal with individuals that resemble themselves, the oddity effect would thus tend to homogenize shoals. An aggregation of fish is the term for any collection of fish that have gathered together in some locality. Fish aggregations can be structured or unstructured, an unstructured aggregation might be a group of mixed species and sizes that have gathered randomly near some local resource, such as food or nesting sites. If, in addition, the aggregation comes together in an interactive, social way, shoaling groups can include fish of disparate sizes and can including mixed-species subgroups. If the shoal becomes more organised, with the fish synchronising their swimming so they all move at the same speed and in the same direction. Schooling fish are usually of the species and the same age/size. Fish schools move with the individual members precisely spaced from each other, the schools undertake complicated manoeuvres, as though the schools have minds of their own. The intricacies of schooling are far from understood, especially the swimming and feeding energetics. Many hypotheses to explain the function of schooling have been suggested, such as orientation, synchronized hunting, predator confusion. Schooling also has disadvantages, such as excretion buildup in the media and oxygen. The way the array in the school probably gives energy saving advantages. Fish can be obligate or facultative shoalers, obligate shoalers, such as tunas, herrings and anchovy, spend all of their time shoaling or schooling, and become agitated if separated from the group. Facultative shoalers, such as Atlantic cod, saiths and some carangids, shoal only some of the time, shoaling fish can shift into a disciplined and coordinated school, then shift back to an amorphous shoal within seconds
Shoaling and schooling
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These
surgeonfish are shoaling. They are swimming somewhat independently, but in such a way that they stay connected, forming a social group.
Shoaling and schooling
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These
bluestripe snapper are schooling. They are all swimming in the same direction in a coordinated way.
Shoaling and schooling
–
Schools of
forage fish often accompany large predator fish. Here a school of
jacks accompany a
great barracuda.
Shoaling and schooling
–
Some coastal
upwellings (red) provide plankton rich feeding grounds for shoals of
forage fish, which in turn attract larger predator fish.
5.
Fishing bank
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An ocean bank, sometimes referred to as a fishing bank or simply bank, is a part of the sea which is shallow compared to its surrounding area, such as a shoal or the top of an underwater hill. Somewhat like continental slopes, ocean banks slopes can upwell as tidal and other flows intercept them, because of this, some large banks, such as Dogger Bank and the Grand Banks of Newfoundland, are among the richest fishing grounds in the world. There are some banks that were reported in the 19th century by navigators, such as Wachusett Reef, ocean banks may be of volcanic nature. Banks may be carbonate or terrigenous, in tropical areas some banks are submerged atolls. As they are not associated with any landmass, banks have no source of sediments. Carbonate banks are typically platforms, rising from the ocean depths, Seamounts, by contrast, are mountains, of volcanic origin, rising from the deep sea, and are steeper, and higher in comparison to the surrounding seabed. Examples of these are Pioneer and Guide Seamounts, west of the Farallon Islands, the Pioneer Seamount has a depth of 1,000 meters, In other cases, parts of a bank may reach above the water surface, thereby forming islands
Fishing bank
–
Georges Bank in the
Gulf of Maine is a large elevated area of the sea floor, shown in this map as the light blue region at the bottom centre.
Fishing bank
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Fisheries
Fishing bank
–
By country
6.
Clupea
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Clupea is genus of planktivorous bony fish belonging to the family Clupeidae, commonly known as herrings. They are found in the shallow, temperate waters of the North Pacific, three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies, herrings are forage fish moving in vast schools, coming in spring to the shores of Europe and America, where they form important commercial fisheries. The species of Clupea belong to the larger family Clupeidae, which comprises some 200 species that share similar features and they are silvery-colored fish that have a single dorsal fin, which is soft, without spines. They have no lateral line and have a lower jaw. See Atlantic herring for videos of juvenile herring feeding by catching copepods, predators of herring include humans, seabirds, dolphins, porpoises, striped bass, seals, sea lions, whales, sharks, dog fish, tuna, cod, salmon, and halibut. Other large fish also feed on adult herring, young herring feed on phytoplankton and as they mature they start to consume larger organisms. Adult herring feed on zooplankton, tiny animals that are found in surface waters. Copepods and other crustaceans are the most common zooplankton eaten by herring. During daylight herring stay in the safety of deep water, feeding at the only at night when there is less chance of being seen by predators. They swim along with their mouths open, filtering the plankton from the water as it passes through their gills, adult herring are harvested for their meat and eggs, and they are often used as baitfish. The trade in herring is an important sector of national economies. In Europe the fish has been called the silver of the sea, environmental Defense have suggested that the Atlantic herring fishery is one of the more environmentally responsible fisheries
Clupea
Clupea
–
Atlantic herring (Clupea harengus)
Clupea
–
Commercial herring catch
Clupea
–
Medieval herring fishing in
Scania, 1555
7.
Pacific Ocean
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The Pacific Ocean is the largest and deepest of the Earths oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean in the south and is bounded by Asia and Australia in the west, the Mariana Trench in the western North Pacific is the deepest point in the world, reaching a depth of 10,911 metres. Both the center of the Water Hemisphere and the Western Hemisphere are in the Pacific Ocean, the oceans current name was coined by Portuguese explorer Ferdinand Magellan during the Spanish circumnavigation of the world in 1521, as he encountered favourable winds on reaching the ocean. He called it Mar Pacífico, which in both Portuguese and Spanish means peaceful sea, important human migrations occurred in the Pacific in prehistoric times. Long-distance trade developed all along the coast from Mozambique to Japan, trade, and therefore knowledge, extended to the Indonesian islands but apparently not Australia. By at least 878 when there was a significant Islamic settlement in Canton much of trade was controlled by Arabs or Muslims. In 219 BC Xu Fu sailed out into the Pacific searching for the elixir of immortality, from 1404 to 1433 Zheng He led expeditions into the Indian Ocean. The east side of the ocean was discovered by Spanish explorer Vasco Núñez de Balboa in 1513 after his expedition crossed the Isthmus of Panama and he named it Mar del Sur because the ocean was to the south of the coast of the isthmus where he first observed the Pacific. Later, Portuguese explorer Ferdinand Magellan sailed the Pacific East to West on a Castilian expedition of world circumnavigation starting in 1519, Magellan called the ocean Pacífico because, after sailing through the stormy seas off Cape Horn, the expedition found calm waters. The ocean was often called the Sea of Magellan in his honor until the eighteenth century, sailing around and east of the Moluccas, between 1525 and 1527, Portuguese expeditions discovered the Caroline Islands, the Aru Islands, and Papua New Guinea. In 1542–43 the Portuguese also reached Japan, in 1564, five Spanish ships consisting of 379 explorers crossed the ocean from Mexico led by Miguel López de Legazpi and sailed to the Philippines and Mariana Islands. The Manila galleons operated for two and a half centuries linking Manila and Acapulco, in one of the longest trade routes in history, Spanish expeditions also discovered Tuvalu, the Marquesas, the Cook Islands, the Solomon Islands, and the Admiralty Islands in the South Pacific. In the 16th and 17th century Spain considered the Pacific Ocean a Mare clausum—a sea closed to other naval powers, as the only known entrance from the Atlantic the Strait of Magellan was at times patrolled by fleets sent to prevent entrance of non-Spanish ships. On the western end of the Pacific Ocean the Dutch threatened the Spanish Philippines, Spain also sent expeditions to the Pacific Northwest reaching Vancouver Island in southern Canada, and Alaska. The French explored and settled Polynesia, and the British made three voyages with James Cook to the South Pacific and Australia, Hawaii, and the North American Pacific Northwest, one of the earliest voyages of scientific exploration was organized by Spain in the Malaspina Expedition of 1789–1794. It sailed vast areas of the Pacific, from Cape Horn to Alaska, Guam and the Philippines, New Zealand, Australia, and the South Pacific. Growing imperialism during the 19th century resulted in the occupation of much of Oceania by other European powers, and later, Japan, in Oceania, France got a leading position as imperial power after making Tahiti and New Caledonia protectorates in 1842 and 1853 respectively. After navy visits to Easter Island in 1875 and 1887, Chilean navy officer Policarpo Toro managed to negotiate an incorporation of the island into Chile with native Rapanui in 1888, by occupying Easter Island, Chile joined the imperial nations
Pacific Ocean
–
Maris Pacifici by
Ortelius (1589). One of the first printed maps to show the Pacific Ocean; see also
Waldseemüller map (1507).
Pacific Ocean
–
The Pacific Ocean
Pacific Ocean
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USS
Lexington under air attack on 8 May 1942 during the
Battle of the Coral Sea
Pacific Ocean
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Map of the Pacific Ocean during European Exploration, circa 1702–1707.
8.
Atlantic Ocean
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The Atlantic Ocean is the second largest of the worlds oceans with a total area of about 106,460,000 square kilometres. It covers approximately 20 percent of the Earths surface and about 29 percent of its surface area. It separates the Old World from the New World, the Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Eurasia and Africa to the east, and the Americas to the west. The Equatorial Counter Current subdivides it into the North Atlantic Ocean, in contrast, the term Atlantic originally referred specifically to the Atlas Mountains in Morocco and the sea off the Strait of Gibraltar and the North African coast. The Greek word thalassa has been reused by scientists for the huge Panthalassa ocean that surrounded the supercontinent Pangaea hundreds of years ago. The term Aethiopian Ocean, derived from Ancient Ethiopia, was applied to the Southern Atlantic as late as the mid-19th century, many Irish or British people refer to the United States and Canada as across the pond, and vice versa. The Black Atlantic refers to the role of ocean in shaping black peoples history. Irish migration to the US is meant when the term The Green Atlantic is used, the term Red Atlantic has been used in reference to the Marxian concept of an Atlantic working class, as well as to the Atlantic experience of indigenous Americans. Correspondingly, the extent and number of oceans and seas varies, the Atlantic Ocean is bounded on the west by North and South America. It connects to the Arctic Ocean through the Denmark Strait, Greenland Sea, Norwegian Sea, to the east, the boundaries of the ocean proper are Europe, the Strait of Gibraltar and Africa. In the southeast, the Atlantic merges into the Indian Ocean, the 20° East meridian, running south from Cape Agulhas to Antarctica defines its border. In the 1953 definition it extends south to Antarctica, while in later maps it is bounded at the 60° parallel by the Southern Ocean, the Atlantic has irregular coasts indented by numerous bays, gulfs, and seas. Including these marginal seas the coast line of the Atlantic measures 111,866 km compared to 135,663 km for the Pacific. Including its marginal seas, the Atlantic covers an area of 106,460,000 km2 or 23. 5% of the ocean and has a volume of 310,410,900 km3 or 23. 3%. Excluding its marginal seas, the Atlantic covers 81,760,000 km2 and has a volume of 305,811,900 km3, the North Atlantic covers 41,490,000 km2 and the South Atlantic 40,270,000 km2. The average depth is 3,646 m and the maximum depth, the bathymetry of the Atlantic is dominated by a submarine mountain range called the Mid-Atlantic Ridge. It runs from 87°N or 300 km south of the North Pole to the subantarctic Bouvet Island at 42°S, the MAR divides the Atlantic longitudinally into two halves, in each of which a series of basins are delimited by secondary, transverse ridges. The MAR reaches above 2000 m along most of its length, the MAR is a barrier for bottom water, but at these two transform faults deep water currents can pass from one side to the other
Atlantic Ocean
–
The Atlantic Ocean as seen from the western coast of
Portugal
Atlantic Ocean
–
The Atlantic Ocean, not including
Arctic and
Antarctic regions
Atlantic Ocean
–
The Atlantic Ocean as seen from
Atlantic City, New Jersey.
Atlantic Ocean
–
Myrtle Beach, South Carolina view of the Atlantic Ocean.
9.
Baltic Sea
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The Baltic Sea is a sea of the Atlantic Ocean, enclosed by Scandinavia, Finland, the Baltic countries, and the North European Plain. It includes the Gulf of Bothnia, the Bay of Bothnia, the Gulf of Finland, the Gulf of Riga, the sea stretches from 53°N to 66°N latitude and from 10°E to 30°E longitude. The Baltic Sea is connected by waterways to the White Sea via the White Sea Canal. Traffic history Historically, the Kingdom of Denmark collected Sound Dues from ships at the border between the ocean and the land-locked Baltic Sea and they were collected in the Øresund at Kronborg castle near Helsingør, in the Great Belt at Nyborg. In the Little Belt, the site of intake was moved to Fredericia, the narrowest part of Little Belt is the Middelfart Sund near Middelfart. Oceanography Geographers widely agree that the physical border of the Baltic is a line drawn through the southern Danish islands, Drogden-Sill. The Drogden Sill is situated north of Køge Bugt and connects Dragør in the south of Copenhagen to Malmö, it is used by the Øresund Bridge, including the Drogden Tunnel. By this definition, the Danish Straits are part of the entrance, but the Bay of Mecklenburg, another usual border is the line between Falsterbo, Sweden and Stevns Klint, Denmark, as this is the southern border of Øresund. Its also the border between the shallow southern Øresund and notably deeper water, hydrography and biology Drogden Sill sets a limit to Øresund and Darss Sill, and a limit to the Belt Sea. The shallow sills are obstacles to the flow of salt water from the Kattegat into the basins around Bornholm. The Kattegat and the southwestern Baltic Sea are well oxygenated and have a rich biology, the remainder of the Sea is brackish, poor in oxygen and in species. While Tacitus called it Mare Suebicum after the Germanic people called the Suebi, the origin of the latter name is speculative. Adam of Bremen himself compared the sea with a belt, stating that it is so named because it stretches through the land as a belt and he might also have been influenced by the name of a legendary island mentioned in the Natural History of Pliny the Elder. Pliny mentions an island named Baltia with reference to accounts of Pytheas and it is possible that Pliny refers to an island named Basilia in On the Ocean by Pytheas. Baltia also might be derived from belt and mean near belt of sea, meanwhile, others have suggested that the name of the island originates from the Proto-Indo-European root *bhel meaning white, fair. This root and its meaning were retained in both Lithuanian and Latvian. On this basis, a related hypothesis holds that the name originated from this Indo-European root via a Baltic language such as Lithuanian, yet another explanation is that the name originally meant enclosed sea, bay as opposed to open sea. Some Swedish historians believe the name derives from the god Balder of Nordic mythology, in the Middle Ages the sea was known by variety of names
Baltic Sea
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Cape Arkona on the island of
Rügen in Germany, was a sacred site of the
Slavs before Christianization.
Baltic Sea
–
Map of the Baltic Sea
Baltic Sea
–
The naval
Battle of the Sound took place on 8 November 1658 during the
Dano-Swedish War.
Baltic Sea
–
The burning
Cap Arcona shortly after the attacks, 3 May 1945. Only 350 of the 4,500 prisoners who had been aboard the Cap Arcona survived.
10.
Arabian Sea
–
The Arabian Sea is a region of the northern Indian Ocean bounded on the north by Pakistan and Iran, on the west by northeastern Somalia and the Arabian Peninsula, and on the east by India. Historically the sea has been known by names including the Erythraean Sea. Its total area is 3,862,000 km2 and its depth is 4,652 metres. The Gulf of Aden is in the southwest, connecting the Arabian Sea to the Red Sea through the strait of Bab-el-Mandeb, the Arabian Sea has been crossed by important marine trade routes since the third or second millennium BCE. Major seaports include Jawaharlal Nehru Port in Mumbai, the Port of Karachi and the Gwadar Port in Pakistan, other important ports include in India, Kandla Port, and Mormugao in Goa. The largest islands in the Arabian Sea include Socotra, Masirah Island, Astola Island, the Arabian Seas surface area is about 3,862,000 km2. The maximum width of the Sea is approximately 2,400 km, the biggest river flowing into the Sea is the Indus River. There are also the gulfs of Khambhat and Kutch on the Indian coast, the countries with coastlines on the Arabian Sea are Somalia, Djibouti, Yemen, Oman, United Arab Emirates, Iran, Pakistan, India and the Maldives. There are several cities on the seas coast including Mumbai, Surat, Karachi, Gwadar, Pasni, Ormara, Aden, Muscat, Keti Bandar, Salalah, Duqm. International Hydrographic Organization defines the limits of the Arabian Sea as follows, the Eastern limit of the Gulf of Aden. A line joining Ràs al Hadd, East point of Arabia, a line running from the South extremity of Addu Atoll, to the Eastern extreme of Ràs Hafun. The Western limit of the Laccadive Sea, by the time of Julius Caesar, several well-established combined land-sea trade routes depended upon water transport through the Sea around the rough inland terrain features to its north. Each major route involved transhipping to pack animal caravan, travel through country and risk of bandits. Later the kingdom of Axum arose in Ethiopia to rule a mercantile empire rooted in the trade with Europe via Alexandria, Jawaharlal Nehru Port in Mumbai is the largest port in the Arabian Sea, and the largest container port in India. The Port of Karachi is Pakistans largest and busiest seaport, handling about 60% of the nations cargo and it is located between the Karachi towns of Kiamari and Saddar, close to the main business district and several industrial areas. The geographic position of the places it in close proximity to major shipping routes such as the Strait of Hormuz. The history of the port is intertwined with that of the city of Karachi, several ancient ports have been attributed in the area including Krokola, Morontobara, Barbarikon (the Periplus of the Erythraean Sea, and Debal. It warns sailors about whirlpools and advises them to safety in Kaurashi harbour if they found themselves drifting dangerously
Arabian Sea
–
Arabian Sea from space
Arabian Sea
–
Arabian Sea
Arabian Sea
–
17th century map depicting the locations of the Periplus of the Erythraean Sea
Arabian Sea
–
The
Jawaharlal Nehru Port in Mumbai, India is the largest port of India and one of the busiest in the Arabian Sea
11.
Indian Ocean
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The Indian Ocean is the third largest of the worlds oceanic divisions, covering 70,560,000 km2. It is bounded by Asia on the north, on the west by Africa, on the east by Australia, the Indian Ocean is known as Ratnākara, the mine of gems in ancient Sanskrit literature, and as Hind Mahāsāgar, in Hindi. The northernmost extent of the Indian Ocean is approximately 30° north in the Persian Gulf, the oceans continental shelves are narrow, averaging 200 kilometres in width. An exception is found off Australias western coast, where the width exceeds 1,000 kilometres. The average depth of the ocean is 3,890 m and its deepest point is Diamantina Deep in Diamantina Trench, at 8,047 m deep, Sunda Trench has a depth of 7, 258–7,725 m. North of 50° south latitude, 86% of the basin is covered by pelagic sediments. The remaining 14% is layered with terrigenous sediments, glacial outwash dominates the extreme southern latitudes. The major choke points include Bab el Mandeb, Strait of Hormuz, the Lombok Strait, the Strait of Malacca, the Indian Ocean is artificially connected to the Mediterranean Sea through the Suez Canal, which is accessible via the Red Sea. All of the Indian Ocean is in the Eastern Hemisphere and the centre of the Eastern Hemisphere is in this ocean, marginal seas, gulfs, bays and straits of the Indian Ocean include, The climate north of the equator is affected by a monsoon climate. Strong north-east winds blow from October until April, from May until October south, in the Arabian Sea the violent Monsoon brings rain to the Indian subcontinent. In the southern hemisphere, the winds are milder. When the monsoon winds change, cyclones sometimes strike the shores of the Arabian Sea, the Indian Ocean is the warmest ocean in the world. Long-term ocean temperature records show a rapid, continuous warming in the Indian Ocean, Indian Ocean warming is the largest among the tropical oceans, and about 3 times faster than the warming observed in the Pacific. Research indicates that human induced greenhouse warming, and changes in the frequency, among the few large rivers flowing into the Indian Ocean are the Zambezi, Shatt al-Arab, Indus, Godavari, Krishna, Narmada, Ganges, Brahmaputra, Jubba and Irrawaddy River. The oceans currents are controlled by the monsoon. Two large gyres, one in the northern hemisphere flowing clockwise and one south of the equator moving anticlockwise, during the winter monsoon, however, currents in the north are reversed. Deep water circulation is controlled primarily by inflows from the Atlantic Ocean, the Red Sea, north of 20° south latitude the minimum surface temperature is 22 °C, exceeding 28 °C to the east. Southward of 40° south latitude, temperatures drop quickly, surface water salinity ranges from 32 to 37 parts per 1000, the highest occurring in the Arabian Sea and in a belt between southern Africa and south-western Australia
Indian Ocean
–
The economically important
Silk Road (red) and spice
trade routes (blue) were blocked by the
Ottoman Empire in ca. 1453 with the fall of the
Byzantine Empire. This spurred exploration, and a new sea route around Africa was found, triggering the
Age of Discovery.
Indian Ocean
–
Extent of the Indian Ocean according to the
CIA World Factbook
Indian Ocean
–
British heavy cruisers
Dorsetshire and
Cornwall under Japanese air attack and heavily damaged on 5 April 1942
Indian Ocean
–
A
dhow off the coast of Kenya
12.
Bengal
–
Bengal is a geopolitical, cultural and historical region in Asia, which is located in the eastern part of the Indian subcontinent at the apex of the Bay of Bengal. Geographically, it is made up by the Ganges-Brahmaputra delta system, in 2011, the population of Bengal was estimated to be 250 million, making it the most densely populated region in South Asia. An estimated 160 million people live in Bangladesh, while 91.3 million people live in West Bengal, the predominant ethno-linguistic group are the Bengali people, who speak the Indo-Aryan Bengali language. Bengali Muslims are the majority in Bangladesh, Bengali Hindus are the majority in West Bengal. Dense woodlands, including rainforests, cover Bengals northern and eastern areas. In the littoral southwest are the Sunderbans, the worlds largest mangrove forest, in the coastal southeast lies Coxs Bazaar, the longest beach in the world at 125 km. The region has a climate, which the Bengali calendar divides into six seasons. Bengal has played a role in the history of Asia. In antiquity, its kingdoms were known as seafaring nations, at times an independent regional empire, or a bastion of larger empires, the historical region was a leading power of the Indian subcontinent and the Islamic East. Bengali culture has had a significant influence on other cultures, especially in the fields of literature, music, art, architecture, sports, currency, commerce, politics and cuisine. The name of Bengal is derived from the ancient kingdom of Banga, theories on the origin of the term Banga point to the Proto-Dravidian Bong tribe that settled in the area circa 1000 BCE and the Austric word Bong. The term Bangaladesa is used to describe the region in 11th century South Indian records, the modern term Bangla is prominent from the 14th century, which saw the establishment of the Sultanate of Bengal, whose first ruler Shamsuddin Ilyas Shah was known as the Shah of Bangala. The Portuguese referred to the region as Bengala in the Age of Discovery, most of the Bengal region lies in the Ganges-Brahmaputra delta, but there are highlands in its north, northeast and southeast. The Ganges Delta arises from the confluence of the rivers Ganges, Brahmaputra, the total area of Bengal is 232,752 km2—West Bengal is 88,752 km2 and Bangladesh 147,570 km2. The flat and fertile Bangladesh Plain dominates the geography of Bangladesh, the Chittagong Hill Tracts and Sylhet regions are home to most of the mountains in Bangladesh. Most parts of Bangladesh are within 10 metres above the sea level, because of this low elevation, much of this region is exceptionally vulnerable to seasonal flooding due to monsoons. The highest point in Bangladesh is in Mowdok range at 1,052 metres, a major part of the coastline comprises a marshy jungle, the Sundarbans, the largest mangrove forest in the world and home to diverse flora and fauna, including the royal Bengal tiger. In 1997, this region was declared endangered, West Bengal is on the eastern bottleneck of India, stretching from the Himalayas in the north to the Bay of Bengal in the south
Bengal
–
Map of Hindoostan in 1831 with Bengal (Green colored at the right)
Bengal
–
Map of the Bengal region
Bengal
–
Mahasthangarh is the oldest archaeological site in
Bangladesh. It dates back to 700 BC and was the ancient capital of the
Pundra Kingdom.
Bengal
–
Asia in 323 BC, the
Nanda Empire of
Magadha and
Gangaridai Empire of Bengal in relation to
Alexander 's Empire and neighbours.
13.
Fisheries science
–
Fisheries science is the academic discipline of managing and understanding fisheries. In some cases new disciplines have emerged, as in the case of bioeconomics, fisheries science is typically taught in a university setting, and can be the focus of an undergraduate, masters or Ph. D. program. Some universities offer fully integrated programs in fisheries science, a web site of the Peter Wall Institute for Advanced Studies promoting ecosystem-based fisheries science
Fisheries science
–
The 78-metre Danish fisheries
research vessel Dana
Fisheries science
–
Ransom A. Myers
Fisheries science
–
Daniel Pauly
Fisheries science
–
Ray Hilborn
14.
Oily fish
–
Oily fish have oil in their tissues and in the belly cavity around the gut. Their fillets contain up to 30% oil, although this figure varies both within and between species, examples include small forage fish, such as sardines, herring and anchovies, and other larger pelagic fish, such as salmon, trout, tuna and mackerel. Oily fish can be contrasted with fish, which contain oil only in the liver. Examples of white fish are cod, haddock and flatfish, white fish are usually demersal fish which live on or near the seafloor, whereas oily fish are pelagic, living in the water column away from the bottom. Oily fish meat is a source of vitamins A and D. Among other benefits, studies suggest that the fatty acids in oily fish may help improve inflammatory conditions such as arthritis. A1997 study published in Annals of Neurology followed 5,386 elderly participants in Rotterdam and it found that fish consumption decreased the risk of dementia. However, the 2. 1-year average follow-up was less than the three years dementia commonly affects people prior to diagnosis, thus, the study was unclear as to whether fish consumption protected against dementia, or if dementia prevented the participants from wanting more fish. The conclusion was that people who ate fish at least once a week had a lower risk of being diagnosed with dementia over a seven-year period. This study reinforced the Annals of Neurology findings, because of the longer term, the BMJ study provided stronger evidence of a genuine protective effect. There was a possible confounding factor in that individuals with higher education have both a lower risk of dementia and higher consumption of fish, consuming 200–400 g of oily fish twice per week may also help prevent sudden death due to myocardial infarction by preventing cardiac arrhythmia. In 1994, the UK Committee on Medical Aspects of Food, the United States Environmental Protection Agencys Exposure Reference Dose for MeHg is 0.1 micrograms per kg body weight per day. The corresponding limit of blood mercury is 5.8 micrograms per liter, there is no recommended limit on the consumption of white fish. There are limits, however, for nursing/pregnant women and children under the age of six and this population should completely avoid fish with high risk of mercury contamination and limit consumption of moderate and low-mercury fish to 12 ounces or fewer per week. Albacore tuna should be limited to six ounces or less per week, concerns about contamination, diet or supply have led to investigation of plant sources of omega-3 fatty acids, notably flax, hempseed and perilla oils. The End of the Line, How overfishing is changing the world, ISBN 0-09-189780-7 Achieving optimal essential fatty acid status in vegetarians, current knowledge and practical implications Whats an oily fish. From the UK Foods Standards Agency BUPA article on oily fish George Monbiot on the problems of sourcing omega-3 from fish
Oily fish
–
Large
open-water fish, like this
Atlantic bluefin tuna, are oily fish.
Oily fish
–
Most small
forage fish, like these
schooling anchovies, are also oily fish.
Oily fish
–
Oily fish fillet (
salmon – bottom) contrasted with a
white fish fillet (
halibut – top)
Oily fish
–
Grilled salmon, an oily fish
15.
Food fish
–
Fish are consumed as food by many species, including humans. It has been an important source of protein and other nutrients for humans throughout recorded history, in culinary and fishery contexts, the term fish can also include shellfish, such as molluscs, crustaceans and echinoderms. English does not distinguish between fish as an animal and the food prepared from it, as it does with pig vs. pork or cow vs. beef, some other languages do, as in the Spanish peces versus pescado. The modern English word for fish comes from the Old English word fisc which was pronounced as it is today, English also has the term seafood, which covers fish found in the seas and oceans as well as other marine life used as food. Over 32,000 species of fish have been described, making them the most diverse group of vertebrates, in addition, there are many species of shellfish. However, only a number of species are commonly eaten by humans. Fish can be prepared in a variety of ways and it can be cured by marinating, pickling, or smoking. Or it can be cooked by baking, frying, grilling, poaching, many of the preservation techniques used in different cultures have since become unnecessary but are still performed for their resulting taste and texture when consumed. Intermediate Technology Publications wrote in 1992 that Fish provides a source of high quality protein and contains many vitamins. It may be classed as either whitefish, oily fish, or shellfish, whitefish, such as haddock and seer, contain very little fat whereas oily fish, such as sardines, contain between 10-25%. The latter, as a result of its fat content, contain a range of fat-soluble vitamins and essential fatty acids. This has highlighted the role for fish in the functionality of the human body, Fish is the most common food to obstruct the airway and cause choking. Choking on fish was responsible for about 4,500 reported accidents in the UK in 1998, a seafood allergy is a hypersensitivity to an allergen which can be present in fish, and particularly in shellfish. This can result in an overreaction of the system and lead to severe physical symptoms. Most people who have a food allergy also have a seafood allergy, allergic reactions can result from ingesting seafood, or by breathing in vapours from preparing or cooking seafood. The most severe seafood allergy reaction is anaphylaxis, an emergency requiring immediate attention, some species of fish, notably the puffer fugu used for sushi, and some kinds of shellfish, can result in serious poisoning if not prepared properly. These fish always contain these poisons as a defense against predators, particularly, fugu has a lethal dose of tetrodotoxin in its internal organs and must be prepared by a licensed fugu chef who has passed the national examination in Japan. Ciguatera poisoning can occur from eating fish from warm tropical waters, such as sea bass, grouper
Food fish
–
Redbelly
tilapia presented as food
Food fish
–
Halibut fillet (a
whitefish) on top of a salmon fillet (an
oily fish)
Food fish
–
Specially prepared dish of the poisonous blowfish
fugu, Japan
Food fish
–
Hawaiian food: Seared ahi and
wasabi beurre blanc sauce
16.
Salted fish
–
Salted fish, such as kippered herring or dried and salted cod, is fish cured with dry salt and thus preserved for later eating. Drying or salting, either dry salt or with brine, was the only widely available method of preserving fish until the 19th century. Dried fish and salted fish are a staple of diets in the Caribbean, North Africa, Southeast Asia, Southern China, Scandinavia, coastal Russia, like other salt-cured meats, it provides preserved animal protein even in the absence of electrically powered refrigeration. Salting is the preservation of food with dry edible salt and it is related to pickling, and is one of the oldest methods of preserving food. Salt inhibits the growth of microorganisms by drawing out of microbial cells through osmosis. Concentrations of salt up to 20% are required to kill most species of unwanted bacteria, smoking, often used in the process of curing meat, adds chemicals to the surface of meat that reduce the concentration of salt required. Salting is used because most bacteria, fungi and other pathogenic organisms cannot survive in a highly salty environment. Any living cell in such an environment will become dehydrated through osmosis, the water activity, aw, in a fish is defined as the ratio of the water vapour pressure in the flesh of the fish to the vapour pressure of pure water at the same temperature and pressure. It ranges between 0 and 1, and is a parameter that measures how available the water is in the flesh of the fish, available water is necessary for the microbial and enzymatic reactions involved in spoilage. There are a number of techniques that have been or are used to tie up the water or remove it by reducing the aw. Traditionally, techniques such as drying, salting and smoking have been used, in more recent times, freeze-drying, water binding humectants, and fully automated equipment with temperature and humidity control have been added. Often a combination of techniques is used
Salted fish
–
Reconstruction of the Roman fish-salting plant at
Neapolis
Salted fish
–
Various salted fishes sold in a marketplace in a suburb of
Jakarta,
Indonesia
Salted fish
–
Platforms, called
fish flakes, where cod dry in the sun before being packed in salt
Salted fish
–
Remains of Roman fish-salting plant at
Neapolis
17.
Smoked fish
–
Smoked fish is fish that has been cured by smoking. Foods have been smoked by humans throughout history, originally this was done as a preservative. In more recent times fish is preserved by refrigeration and freezing. According to Jeffrey J. Rozum The process of smoking fish occurs through the use of fire, wood contains three major components that are broken down in the burning process to form smoke. The burning process is called pyrolysis, which is defined as the chemical decomposition by heat. The major wood components are cellulose, hemicellulose and lignin, the major steps in the preparation of smoked fish are salting, cold smoking, cooling, packaging, and storage. Smoking, one of the oldest preservation methods, combines the effects of salting, drying, heating and smoking, typical smoking of fish is either cold or hot. A smokehouse is a building where fish or meat is cured with smoke, in a traditional fishing village, a smokehouse was often attached to a fishermans cottage. The smoked products might be stored in the building, sometimes for a year or more, traditional smokehouses served both as smokers and to store the smoked fish. Fish could be preserved if it was cured with salt and cold smoked for two weeks or longer, smokehouses were often secured to prevent animals and thieves from accessing the food. Today there are two methods of smoking fish, The traditional method and the mechanical method. The traditional method involves the fish being suspended in smokehouses over slowly smouldering wood shavings, the fish are left overnight to be naturally infused with smoke. In the mechanical method smoke is generated through the use of smoke condensates, the flow of smoke in the mechanical kiln is computer controlled and the fish generally spend less time being smoked than in a traditional kiln. High-quality smoked fish is a high–end product sought after by restaurants, the most common types of smoked fish in the US are salmon, mackerel, whitefish and trout, although other smoked fish is also available regionally or from many ethnic stores. Salmon, mackerel and herring are universally available both hot-smoked and cold-smoked, while most other fish is preserved by only one of the smoking methods. A common name for cold-smoked salmon is lox, of many different types are available. Traditionally, lox designates brined rather than smoked salmon, but the boundary between the two types of products has become blurred. Gravad lax or gravlax remains the type that is unmistakably not smoked fish
Smoked fish
–
Racks of
haddock in a homemade smoker. Smouldering at the bottom are hardwood wood chips. The sacking at the back is used to cover the racks while they are smoked.
Smoked fish
–
Medieval
smokehouse, ca. 1465, at the archaeological site of
Walraversijde, a
fishing village on the coast of Belgium.
Smoked fish
–
A smoked
Atlantic mackerel
Smoked fish
–
Smoked fish in smoker
18.
Pickled herring
–
Pickled herring, also known as bismarck herring, is a delicacy in Europe, and has become a part of Baltic, Nordic, Dutch, German, Czech, Polish, Eastern Slavic, Scottish and Ashkenazi Jewish cuisine. Most cured herring uses a two-step curing process, initially, herring is cured with salt to extract water. The second stage involves removing the salt and adding flavorings, typically a vinegar, salt, sugar solution to which such as peppercorn, bay leaves. In recent years, other flavors have also added, due to foreign influences. However, the tradition is strong in Denmark, Sweden, Finland, Norway, The Netherlands, Iceland, onion, sherry, mustard and dill are some of the traditional flavourings. Pickled herrings have been a staple in Northern Europe since Medieval times, being a way to store and transport fish, the herrings would be prepared, then packed in barrels for storage or transportation. This dish is common at Christmas, Easter and Midsummer, where it is eaten with akvavit. In the 19th century, people in Berlin developed a special treat known in English as soused herring or rollmops, rollmops are pickled herring fillets rolled into a cylindrical shape around a piece of pickled gherkin or an onion. The word is borrowed from the German, brined herring is common in Ashkenazi Jewish cuisine, perhaps best known for vorschmack salad known in English simply as chopped herring and as schmaltz herring in Yiddish. In Israel it is called as dag maluach which means salted fish. Pickled herring can also be found in the cuisine of Hokkaidō in Japan, in Nova Scotia, a province of Canada, pickled herring is called solomon gundy and is quite popular. Not to be confused with the Jamaican term for a pickled fish pâté and it is rich in tyramine and thus should be avoided in the diet of people being treated with an antidepressant monoamine oxidase inhibitor. Pickled herring is one of the best sources of natural vitamin D3 and it is also an excellent source of selenium and vitamin B12. 100 grams may provide 680 IU of vitamin D or 170% of the DV, as well as 84% of the DV for selenium, pickled herring is one of the twelve dishes traditionally served at Christmas Eve in Poland, Lithuania, and Ukraine. Herring is enjoyed as a special Shabbos food by Ashkenazi Jews worldwide and it is a staple at Kiddushes and social gatherings. Many kosher establishments have begun to formulate new fusion-style herring dishes such as Oneg-Shabbos herring, younger herring consumers look for new and interesting styles, besides the simple pickled herring with onions. Herring is typically served on such as kichel or Tam Tams
Pickled herring
–
Pickled herring with onions
Pickled herring
–
Pickled herring with sour cream, chives, potatoes and egg
Pickled herring
–
True herrings
Pickled herring
19.
Predator fish
–
Predatory fish are fish that prey upon other fish or animals. Some predatory fish include perch, muskie, pike, walleye, levels of large predatory fish in the global oceans were estimated to be about 10% of their pre-industrial levels by 2003. Large predatory fish are most at risk of extinction, there was a level of large predatory fish extinctions during the Cretaceous–Paleogene extinction event 66 million years ago. Creation of marine reserves has been found to restore populations of predatory fish such as the Serranidae — groupers. Predatory fish switch between types of prey in response to variations in their abundance, such changes in preference are disproportionate and are selected for as evolutionarily efficient. Predatory fish may become a pest if they are introduced into an ecosystem in which they become a new top predator, an example, which has caused much trouble in Maryland and Florida, is the snakehead fish. Predators are an important factor to consider in managing fisheries, and methods for doing so are available, feeding frenzy Scale eating Shark attack Shark feeding Predatory fish on AquaticCommunity. com Predator fish in oceans on alarming decline, experts say Washington Post,21 February 2011
Predator fish
–
About
fish
20.
Billfish
–
The term billfish refers to a group of predatory fish characterised by prominent bills, or rostra, and by their large size, some are longer than 4 m. Billfish include sailfish and marlin, which make up the family Istiophoridae and they are apex predators which feed on a wide variety of smaller fish, crustaceans, and cephalopods. Billfish are pelagic and highly migratory and they are found in all oceans, although they usually inhabit tropical and subtropical waters, swordfish are found in temperate waters, as well. Billfish use their long spears or sword-like upper beaks to slash at and their bills can also be used to spear prey, and have been known to spear boats, but they are not normally used in that way. They are highly valued as gamefish by sports fishermen, the term billfish refers to the fishes of the families Xiphiidae and Istiophoridae. These large fishes are characterized by the prolongation of the jaw, much beyond the lower jaw into a long rostrum which is flat and sword-like or rounded. The 12 species of true billfish are divided into two families and five genera, one family, Xiphiidae, contains only one species, the swordfish Xiphias gladius, and the other family, Istiophoridae contains 11 species in four genera, including marlin, spearfish, and sailfish. Controversy exists about whether the Indo-Pacific blue marlin, Makaira mazara, is the species as the Atlantic blue marlin. FishBase follows Nakamura in recognizing M. mazara as a distinct species, a number of other fishes have pronounced bills or beaks, and are sometimes referred to as billfish. However, they are not true billfish, halfbeaks look somewhat like miniature billfish, and the sawfish and sawshark, which are cartilaginous fishes with spectacular rostrums shaped like a chain saw. Paddlefish have elongated rostrums containing electroreceptors that can detect weak electrical fields, paddlefish are filter feeders and may use their rostrum to detect zooplankton. Billfish have a long, bony, spear-shaped bill, sometimes called a snout, the swordfish has the longest bill, about one-third its body length. Like a true sword, it is smooth, flat, pointed, the bills of other billfish are shorter and rounder, more like spears. Billfish normally use their bills to slash at schooling fish and they swim through the fish school at high speed, slashing left and right, and then circle back to eat the fish they stunned. Adult swordfish have no teeth, and other billfish have only small file-like teeth and they swallow their catch whole, head-first. Billfish dont normally spear with their bills, though occasionally a marlin will flip a fish into the air, given the speed and power of these fish, when they do spear things the results can be dramatic. Predators of billfish, such as white and mako sharks, have been found with billfish spears embedded in them. Pelagic fish generally are fascinated by floating objects, and congregate about them, Billfish can accidentally impale boats and other floating objects when they pursue the small fish that aggregate around them
Billfish
–
The largest billfish, the
Atlantic blue marlin, weighs up to 820 kg (1800 lb) and has been classified as a
vulnerable species.
Billfish
Billfish
Billfish
21.
Bonito
–
Bonitos are a tribe of medium-sized, ray-finned predatory fish in the family Scombridae – a family it shares with the mackerel, tuna, and Spanish mackerel tribes, and also the butterfly kingfish. Also called the Sardini tribe, it consists of eight species across four genera, bonito is an adjective that means pretty applied to males or masculine objects both in Portuguese and Spanish, but it is unclear whether the name of the fish is related to this. However, it is said to be derived of the Italian buono, the bonito has a moderate fat content. Bonito may not be marketed as tuna in all countries, however, the Atlantic bonito is also found in the Mediterranean and the Black Sea, where it is a popular food fish, eaten grilled, pickled, or baked. Other fish sometimes called bonito include skipjack tuna, Katsuwonus pelamis Sardini
Bonito
–
Bonito
22.
Mackerel
–
Mackerel is a common name applied to a number of different species of pelagic fish, mostly, but not exclusively, from the family Scombridae. They are found in temperate and tropical seas, mostly living along the coast or offshore in the oceanic environment. Mackerel typically have stripes on their backs and deeply forked tails. Many species are restricted in their ranges, and live in separate populations or fish stocks based on geography. Some stocks migrate in schools along the coast to suitable spawning grounds. After spawning they return the way they came, in smaller schools, from there they may move offshore into deeper waters and spend the winter in relative inactivity. Smaller mackerel are forage fish for larger predators, including larger mackerel, flocks of seabirds, as well as whales, dolphins, sharks and schools of larger fish such as tuna and marlin follow mackerel schools and attack them in sophisticated and cooperative ways. Mackerel is high in oils and is intensively harvested by humans. In 2009, over five tons were landed by commercial fishermen. Sport fishermen value the fighting abilities of the king mackerel, over thirty different species, principally belonging to the family Scombridae, are commonly referred to as mackerel. The term mackerel means marked or spotted, the term mackerel derives from the Old French maquerel, c.1300, meaning a pimp or procurer. The connection is not altogether clear, but mackerel spawn enthusiastically in shoals near the coast, about 21 species in the family Scombridae are commonly called mackerel. The type species for the mackerel is the Atlantic mackerel. Until recently, it was thought that Atlantic chub mackerel and Indo-Pacific chub mackerel were subspecies of the same species, in 1999 Collette established, on molecular and morphological considerations, that these are separate species. Mackerel are smaller with shorter life cycles than their relatives, the tuna. The true mackerels belong to the tribe Scombrini, the tribe consists of seven species, each belonging to one of two genera, Scomber and Rastrelliger. The Spanish mackerels belong to the tribe Scomberomorini, which is the tribe of the true mackerels. This tribe consists of 21 species in all—18 of those are classified into the genus Scomberomorus, in addition, a number of species with mackerel-like characteristics in the families Carangidae, Hexagrammidae and Gempylidae are commonly referred to as mackerel
Mackerel
–
Some species of mackerel
migrate in
schools for long distances along the coast and other species cross oceans
Mackerel
Mackerel
–
Still life with mackerel, lemon and tomato,
Van Gogh, 1886
Mackerel
–
Mackerel, such as these
Pacific jack mackerel, usually have vertical stripes on their sides which provide "schooling marks", visual clues that help them stay in formation as they
school.
23.
Salmon
–
Salmon /ˈsæmən/ is the common name for several species of ray-finned fish in the family Salmonidae. Other fish in the family include trout, char, grayling. Salmon are native to tributaries of the North Atlantic and Pacific Ocean, many species of salmon have been introduced into non-native environments such as the Great Lakes of North America and Patagonia in South America. Salmon are intensively farmed in parts of the world. Typically, salmon are anadromous, they are born in water, migrate to the ocean. However, populations of species are restricted to fresh water through their lives. Various species of salmon display anadromous life strategies while others display freshwater resident life strategies, folklore has it that the fish return to the exact spot where they were born to spawn, tracking studies have shown this to be mostly true. A portion of a salmon run may stray and spawn in different freshwater systems. The percent of straying depends on the species of salmon, homing behavior has been shown to depend on olfactory memory. The term salmon comes from the Latin salmo, which in turn may have originated from salire, the nine commercially important species of salmon occur in two genera. The genus Salmo contains the Atlantic salmon, found in the north Atlantic, the genus Oncorhynchus contains eight species which occur naturally only in the North Pacific. As a group, these are known as Pacific salmon, Chinook salmon have been introduced in New Zealand and Patagonia. Coho, freshwater sockeye, and Atlantic salmon have established in Patagonia. † Both the Salmo and Oncorhynchus genera also contain a number of species referred to as trout, within Salmo, additional minor taxa have been called salmon in English, i. e. the Adriatic salmon and Black Sea salmon. The steelhead anadromous form of the rainbow trout migrates to sea, also a number of other species have common names which refer to them as being salmon. The British Columbia salmon fossil provides evidence that the divergence between Pacific and Atlantic salmon had not yet occurred 40 million years ago, Both the fossil record and analysis of mitochondrial DNA suggest the divergence occurred by 10 to 20 million years ago. This independent evidence from DNA analysis and the fossil record rejects the theory of salmon divergence. Atlantic salmon reproduce in northern rivers on both coasts of the Atlantic Ocean, landlocked salmon live in a number of lakes in eastern North America and in Northern Europe, for instance in lakes Sebago, Onega, Ladoga, Saimaa, Vänern, and Winnipesaukee
Salmon
–
Pacific salmon leaping at
Willamette Falls,
Oregon
Salmon
Salmon
–
Atlantic salmon, Salmo salar
Salmon
–
Life cycle of Pacific salmon
24.
Shark
–
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha and are the group to the rays. Under this broader definition, the earliest known sharks date back to more than 420 million years ago, acanthodians are often referred to as spiny sharks, though they are not part of Chondrichthyes proper, they are a paraphyletic assemblage leading to cartilaginous fish as a whole. Since then, sharks have diversified into over 500 species, Sharks are found in all seas and are common to depths of 2,000 metres. They generally do not live in freshwater although there are a few exceptions, such as the bull shark and the river shark. Sharks have a covering of dermal denticles that protects their skin from damage and they have numerous sets of replaceable teeth. Well-known species such as the white shark, tiger shark, blue shark, mako shark. Many shark populations are threatened by human activities, until the 16th century, sharks were known to mariners as sea dogs. The etymology of the shark is uncertain. One theory is that it derives from the Yucatec Maya word xok, however, the Middle English Dictionary records an isolated occurrence of the word shark in a letter written by Thomas Beckington in 1442, which rules out a New World etymology. Evidence for the existence of sharks dates from the Ordovician period, 450–420 million years ago, before land vertebrates existed and before many plants had colonized the continents. Only scales have been recovered from the first sharks and not all agree that these are from true sharks. The oldest generally accepted shark scales are from about 420 million years ago, the first sharks looked very different from modern sharks. The majority of sharks can be traced back to around 100 million years ago. Most fossils are of teeth, often in large numbers, partial skeletons and even complete fossilized remains have been discovered. Estimates suggest that sharks grow tens of thousands of teeth over a lifetime, the teeth consist of easily fossilized calcium phosphate, an apatite. When a shark dies, the decomposing skeleton breaks up, scattering the apatite prisms, preservation requires rapid burial in bottom sediments. Among the most ancient and primitive sharks is Cladoselache, from about 370 million years ago, which has been found within Paleozoic strata in Ohio, Kentucky, and Tennessee
Shark
Shark
–
A collection of
Cretaceous shark teeth
Shark
–
The teeth of
tiger sharks are oblique and serrated to saw through flesh
Shark
–
The dermal denticles of a
lemon shark, viewed through a
scanning electron microscope
25.
Tuna
–
A tuna is a saltwater fish that belongs to the tribe Thunnini, a sub-grouping of the mackerel family – which together with the tunas, also includes the bonitos, mackerels, and Spanish mackerels. Thunnini comprises fifteen species across five genera, the sizes of which vary greatly, the bluefin averages 2 m, and is believed to live for up to 50 years. Tuna and mackerel sharks are the species of fish that can maintain a body temperature higher than that of the surrounding water. An active and agile predator, the tuna has a sleek, streamlined body, found in warm seas, it is extensively fished commercially, and is popular as a game fish. As a result of over-fishing, stocks of tuna species such as the southern bluefin tuna have been reduced dangerously close to the point of extinction. The term tuna ultimately derives from Thunnus, the Middle Latin form of the Ancient Greek, θύννος tunny-fish – which is in turn derived from θύνω, rush, the following cladogram illustrates the relationship between the tunas and other tribes of the family Scombridae. The true tunas are those that belong to the genus Thunnus, until recently, it was thought that there were seven Thunnus species, and that Atlantic bluefin tuna and Pacific bluefin tuna were subspecies of a single species. In 1999, Collette established that based on molecular and morphological considerations, they are in fact distinct species. The genus Thunnus is further classified into two subgenera, Thunnus, and Thunnus, the Thunnini tribe also includes seven additional species of tuna across four genera. They are, The tuna is a sleek and streamlined fish and it has two closely spaced dorsal fins on its back, The first is depressible – it can be laid down, flush, in a groove that runs along its back. Seven to ten yellow finlets run from the fins to the tail. The caudal peduncle, to which the tail is attached, is quite thin, the tunas dorsal side is generally a metallic dark blue, while the ventral side, or underside, is silvery or whitish, for camouflage. Thunnus are widely but sparsely distributed throughout the oceans of the world, generally in tropical, all tunas are able to maintain the temperature of certain parts of their body above the temperature of ambient seawater. For example, bluefin can maintain a body temperature of 25–33 °C. However, unlike typical endothermic creatures such as mammals and birds, tunas achieve endothermy by conserving the heat generated through normal metabolism. In all tunas, the heart operates at ambient temperature, as it receives cooled blood, also unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red myotomal muscles derive their color from myoglobin, an oxygen-binding molecule, the oxygen-rich blood further enables energy delivery to their muscles. For powerful swimming animals like dolphins and tuna, cavitation may be detrimental, even if they have the power to swim faster, dolphins may have to restrict their speed, because collapsing cavitation bubbles on their tail are too painful
Tuna
Tuna
–
Tuna
Tuna
–
Relative sizes of various tunas, with the
Atlantic bluefin tuna (top) at about 8 ft (2.4 m) in this sample
Tuna
–
Tuna being weighed on Greek quay-side
26.
Anchovy
–
An anchovy is a small, common salt-water forage fish of the family Engraulidae. The 144 species are placed in 17 genera, they are found in the Atlantic, Indian, and Pacific Oceans, and in the Black Sea, Anchovies are usually classified as oily fish. Anchovies are small, green fish with blue reflections due to a longitudinal stripe that runs from the base of the caudal fin. They range from 2 to 40 cm in length. The snout is blunt with tiny, sharp teeth in both jaws, the snout contains a unique rostral organ, believed to be sensory in nature, although its exact function is unknown. The mouth is larger than that of herrings and silversides, two fish which anchovies closely resemble in other respects, the anchovy eats plankton and recently hatched fish. Anchovies are found in scattered areas throughout the oceans, but are concentrated in temperate waters. They are generally accepting of a wide range of temperatures. Large schools can be found in shallow, brackish areas with muddy bottoms, as in estuaries and they are abundant in the Mediterranean, particularly in the Alboran Sea, Aegean Sea and the Black Sea. The species is caught along the coasts of Crete, Greece, Sicily, Italy, France, Turkey. They are also found on the coast of northern Africa, the range of the species also extends along the Atlantic coast of Europe to the south of Norway. Spawning occurs between October and March, but not in water colder than 12 °C, the anchovy appears to spawn at least 100 km from the shore, near the surface of the water. The anchovy is a significant food source for almost every predatory fish in its environment, including the California halibut, rock fish, yellowtail, shark, chinook, and coho salmon. It is also important to marine mammals and birds, for example, breeding success of California brown pelicans. Anchovies, like most clupeoids, are filter-feeders that open their mouths as they swim, as water passes through the mouth and out the gills, food particles are sieved by gill rakers and transferred into the esophagus. * Type species On average, the Turkish commercial fishing fleet catches around 300,000 tons per year, the largest catch is in November and December. The Peruvian anchovy fishery is one of the largest in the world, in 1973 it collapsed catastrophically due to the combined effects of overfishing and El Niño and did not recover fully for two decades. A traditional method of processing and preserving anchovies is to gut and salt them in brine, allow them to mature and this results in a characteristic strong flavor and the flesh turns deep grey
Anchovy
–
Anchovies
Anchovy
–
European anchovy, Engraulis encrasicolus
Anchovy
Anchovy
–
Still Life with Anchovies, 1972,
Antonio Sicurezza
27.
Herring
–
Herring are forage fish, mostly belonging to the family Clupeidae. Herring often move in schools around fishing banks and near the coast. Three species of Clupea are recognised, and provide about 90% of all captured in fisheries. Most abundant of all is the Atlantic herring, providing half of all herring capture. Fishes called herring are found in India, in the Arabian Sea, Indian Ocean. Herring played a role in the history of marine fisheries in Europe. These oily fish also have a history as an important food fish. A number of different species, most belonging to the family Clupeidae, are referred to as herrings. The origins of the herring is somewhat unclear, though it may derive from the Old High German heri meaning a host, multitude. The type genus of the herring family Clupeidae is Clupea, Clupea contains three species, the Atlantic herring found in the north Atlantic, the Pacific herring found in the north Pacific, and the Araucanian herring found off the coast of Chile. Subspecific divisions have been suggested for both the Atlantic and Pacific herrings, but their biological basis remain unclear, in addition, a number of related species, all in the family Clupeidae, are commonly referred to as herrings. The table immediately below includes those members of the Clupeidae family referred to by FishBase as herrings which have been assessed by the International Union for Conservation of Nature. There are also a number of other species called herrings, which may be related to clupeids or just share some characteristics of herrings. Just which of these species are called herrings can vary with locality, some examples, The species of Clupea belong to the larger family Clupeidae, which comprises some 200 species that share similar features. These silvery-coloured fish have a dorsal fin, which is soft. They have no lateral line and have a lower jaw. At least one stock of Atlantic herring spawns in every month of the year, each spawns at a different time and place. Greenland populations spawn in 0–5 metres of water while North Sea herrings spawn at up to 200 metres in autumn
Herring
–
The
Atlantic herring, Clupea harengus
Herring
–
Global commercial capture of herrings in million tonnes reported by the
FAO 1950–2010
Herring
Herring
–
Clupea pallasii, the Pacific herring
28.
Menhaden
–
Menhaden, also known as mossbunker and bunker, are forage fish of the genera Brevoortia and Ethmidium, two genera of marine fish in the family Clupeidae. Menhaden is a blend of poghaden and an Algonquian word akin to Narragansett munnawhatteaûg, derived from munnohquohteau ‘he fertilizes’ and it is generally thought that Pilgrims were advised by Tisquantum to plant menhaden with their crops. Menhaden are flat, have soft flesh, and a forked tail. They rarely exceed 15 inches in length, and have a weight range. Gulf menhaden and Atlantic menhaden are small oily-fleshed fish, bright silver and they tend to have larger scales than Yellowfin menhaden and Finescale menhaden. In addition, Yellowfin menhaden tail rays are a yellow in contrast to those of the Atlantic menhaden. Recent taxonomic work using DNA comparisons have organized the North American menhadens into large-scaled and small-scaled designations, Menhaden have two main sources of food, phytoplankton and zooplankton. A menhaden’s diet varies considerably over the course of its lifetime, the smallest menhaden, typically those under one year old, eat primarily phytoplankton. After that age, adult menhaden gradually shift to a diet comprised almost exclusively of zooplankton, Menhaden are omnivorous filter feeders, feeding by straining plankton and algae from water. Along with oysters, which water on the sea bed, menhaden play a key role in the food chain in estuaries. Atlantic menhaden are an important link between plankton and upper level predators, because of their filter feeding abilities, menhaden consume and redistribute a significant amount of energy within and between Chesapeake Bay and other estuaries, and the coastal ocean. Because they play this role, and their abundance, menhaden are a prey species for many predatory fish, such as striped bass, bluefish, mackerel, flounder, tuna, drums. They are also an important food source for many birds, including egrets, ospreys, seagulls, northern gannets, pelicans. In 2012 the Atlantic States Marine Fisheries Commission declared that the Atlantic menhaden was depleted due to overfishing, the decision was driven by issues with water quality in the Chesapeake Bay and failing efforts to re-introduce predator species, due to lack of menhaden on which they could feed. Menhaden are not used directly for food and they are processed into fish oil and fish meal that are used as food ingredients, animal feed, and dietary supplements. It has a high fat content. Fish oil made from menhaden also is used as a raw material for such as lipstick. According to James Kirkley of the Virginia Institute of Marine Science, the first is known as a reduction fishery
Menhaden
–
Gulf menhaden, Brevoortia patronus
Menhaden
–
Atlantic menhaden, Brevoortia tyrannus
Menhaden
–
Pacific menhaden, Ethmidium maculatum
Menhaden
29.
Sardine
–
Sardine and pilchard are common names used to refer to various small, oily fish within the herring family of Clupeidae. The term sardine was first used in English during the early 15th century and may come from the Mediterranean island of Sardinia, the terms sardine and pilchard are not precise, and what is meant depends on the region. The United Kingdoms Sea Fish Industry Authority, for example, classifies sardines as young pilchards, one criterion suggests fish shorter in length than 15 cm are sardines, and larger fish are pilchards. Typically, sardines are caught with encircling nets, particularly purse seines, many modifications of encircling nets are used, including traps or weirs. The latter are stationary enclosures composed of stakes into which schools of sardines are diverted as they swim along the coast, the fish are caught mainly at night, when they approach the surface to feed on plankton. After harvesting, the fish are submerged in brine while they are transported to shore, sardines are commercially fished for a variety of uses, for bait, for immediate consumption, for drying, salting, or smoking, and for reduction into fish meal or oil. The chief use of sardines is for consumption, but fish meal is used as animal feed, while sardine oil has many uses, including the manufacture of paint, varnish. Sardines are commonly consumed by human beings, fresh sardines are often grilled, pickled or smoked, or preserved in cans. Sardines are rich in vitamins and minerals, a small serving of sardines once a day can provide 13 percent of vitamin B2, roughly one-quarter of niacin, and about 150 percent of the recommended daily value of vitamin B12. All B vitamins help to support proper nervous system function and are used for energy metabolism, also, sardines are high in the major minerals such as phosphorus, calcium, potassium, and some trace minerals including iron and selenium. Sardines are also a source of marine omega-3 fatty acids. Recent studies suggest that consumption of omega-3 fatty acids reduces the likelihood of developing Alzheimers disease. These fatty acids can also lower blood sugar levels and they are also a good source of vitamin D, calcium, vitamin B12, and protein. Because they are low in the chain, sardines are very low in contaminants such as mercury. Pilchard fishing and processing became an industry in Cornwall from around 1750 to around 1880. Catches varied from year to year and, in 1871 the catch was 47,000 hogsheads while in 1877 only 9,477 hogsheads, a hogshead contained 2,300 to 4,000 pilchards and, when filled with pressed pilchards, weighed 476 lbs. The pilchards were exported to Roman Catholic countries such as Italy. The chief market for the oil was Bristol where it is used on machinery, as of 2007, however, stocks are improving
Sardine
–
Sardines are small
epipelagic fish that sometimes
migrate along the coast in
large schools. They are an important
forage fish for larger forms of marine life.
Sardine
Sardine
–
The
European pilchard, Sardina pilchardus
Sardine
–
In the 1980s the
South American pilchard, Sardinops sagax, was the most intensively fished species of sardine. Some major
stocks declined precipitously in the 1990s (see chart below).
30.
Shad
–
The Alosinae, or the shads, are a subfamily of fishes in the herring family Clupeidae. The subfamily comprises seven genera worldwide, and about 30 species, the shads are pelagic schooling fish, of which many are anadromous or even landlocked. Several species are of importance, e. g. in the genus Alosa, Brevoortia. The Shad Foundation Shad Planking, a Virginia political gathering featuring the consumption of shad
Shad
–
Alosinae
Least concern[13]
Data deficient[18]
Vulnerable[43]
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