Striped marlin | |
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Scientific classification ![]() | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Actinopterygii |
Order: | Istiophoriformes |
Family: | Istiophoridae |
Genus: | Kajikia |
Species: | K. audax |
Binomial name | |
Kajikia audax (Philippi {Krumweide}, 1887) | |
Synonyms | |
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The striped marlin (Tetrapturus audax, also Kajikia audax) is a species of marlin found globally in tropical to temperate oceans not far from the surface. It is a desirable commercial and game fish, although conservation measures are in place to restrict its commercial landings. An epipelagic predator, it hunts during the day in the top 100 metres (330 ft) or so of the water column, often near the surface. One of its chief prey is sardines.
The striped marlin has a torpedo-like body, dark blue or black above and silvery-white below, with an average length of 2.9 m (9.5 ft), a maximum length of 4.2 m (13.8 ft), and weight up to 220 kg (490 lb). [2] Its first dorsal fin is tall, of the same dimension or greater than its body depth, with 42-48 rays[ clarify ]; the second is much smaller. It has around 12-20 pronounced bluish stripes on the sides of its body, which display even after death. Chromatophores, specialized pigmentation cells, contract or expand to enable the stripes to transform from blue-tinged to lavender when the fish is excited. [3]
The striped marlin is epipelagic, residing away from shore but near the surface of the water. [4] It is widely distributed around the world, and typically found in tropical and/or temperate water bodies. [5] A study on its habitat preferences utilized opportunistic occurrence data to determine that the eastern Pacific Ocean is among the most ideal bodies of water for the species to inhabit. [6] Additionally, it was discovered that its largest populations reside in water bodies with dissolved oxygen levels from 4.5 to 5.5 mL/L and a sea surface temperature between 20 and 28 degrees Celsius. [6]
It was also determined that Chlorophyll a levels are of the greatest importance when it comes to striped marlin distribution. [6] High levels of chlorophyll a in a water body are indicative of high productivity, or nutrient level, within that aquatic ecosystem. [7] An abundance of nutrients supports the growth of aquatic plants and algae, which contributes to the congregation of species that feed upon them, the striped marlin's principle prey. [6]
The striped marlin has also demonstrated diel vertical migration patterns. [8] A study observed that it tends to occupy deep regions of the water during the day, and typically gather near the surface at night. These patterns were prominent in all of the regions tested in the study, including waters off of Australia, New Zealand, Mexico, California, and Ecuador. [8]
The striped marlin can live up to 10 years, and reaches sexual maturity at the age of 1–2 years or 1.4 m (4.6 ft) for males and 1.5-2.5 years or 1.8 m (5.9 ft) for females. It spawns serially during its summer spawning season, which consists of anywhere from 4 to 41 spawning events, with females releasing batches of their up to 120 million eggs every few days. [3] [9] [10]
The striped marlin is a top predator, feeding mainly on a wide range of fish such as sardines, mackerel, small tuna, and cephalopods. One study off the coast of Mexico found that it preferred schooling fish such as the chub mackerel, Etrumeus sadina and Sardinops caeruleus. It also feeds on some species of squid, most commonly the jumbo. [11]
Striped marlin are protected in the United States by The Billfish Conservation Act of 2012, [12] which prohibits the distribution, sale, and possession with the intent to sell of billfish and/or billfish products. This highly restrictive law was enacted to help stem the significant downward trend in global billfish populations despite previously enacted management practices, likely due to generalized overfishing. Exemptions to this law on sale and custody with the intent to sell include billfish caught by U.S. fishing vessels and landed and retained in Hawaii or Pacific Insular Areas, and billfish landed by foreign vessels in the Pacific Insular Areas and exported to markets outside the U.S. or retained within Hawaii and the Pacific Insular Areas for local consumption. [12]
In spite of the U.S.'s ban on commercial taking in most of its waters, the overfishing status of the striped marlin varies by geographical region. For instance, the striped marlin population is stable in the Eastern Pacific Ocean but is overfished in the Western and Central North Pacific Ocean. The international conservation efforts for the striped marlin are managed by the Inter-American Tropical Tuna Commission (IATTC) and the Western and Central Pacific Fisheries Commission (WCFPC), whereas the domestic U.S. conservation efforts are managed by the National Oceanic and Atmospheric Administration (NOAA) and the Western Pacific Fishery Management Council. [13]
In 2010, Greenpeace International added the striped marlin to its "red seafood list", its list of commonly consumed fish which have a very high risk of being sourced from unsustainable fisheries." [14]
The striped marlin is consumed all around the world. [15] Its firm meat can range from light pink to orangish red in color, [13] and has a flavor comparable to but stronger than swordfish. [13] It is generally enjoyed grilled; limited uses include smoking and raw consumption. [3] Typical of other fish species, the striped marlin is an ideal source of omega-3 fatty acids and other essential vitamins and minerals. Also, it is a lean source of protein with minimal sodium and low levels of saturated fat, making it a practical choice for a nutritious meal. [13]
As indicated above, commercial landings are prohibited in most U.S. territorial waters, and additional global conservation measures are in place to protect it from overfishing. Greenpeace includes striped marlin on its "red seafood list". [14]
Landings of striped marlin peaked around 25,000 tonnes annually in the 1960s, but due to both overfishing and conservation efforts have returned to 1950s levels (of approximately 7,500 tonnes annually) in the first two decades of the 2000s.
The swordfish, also known as the broadbill in some countries, are large, highly migratory predatory fish characterized by a long, flat, pointed bill. They are a popular sport fish of the billfish category, though elusive. Swordfish are elongated, round-bodied, and lose all teeth and scales by adulthood. These fish are found widely in tropical and temperate parts of the Atlantic, Pacific, and Indian Oceans, and can typically be found from near the surface to a depth of 550 m (1,800 ft), and exceptionally up to depths of 2,234 m. They commonly reach 3 m (10 ft) in length, and the maximum reported is 4.55 m in length and 650 kg (1,430 lb) in weight.
Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place. Commercial fisheries include wild fisheries and fish farms, both in freshwater waterbodies and the oceans. About 500 million people worldwide are economically dependent on fisheries. 171 million tonnes of fish were produced in 2016, but overfishing is an increasing problem, causing declines in some populations.
The albacore, known also as the longfin tuna, is a species of tuna of the order Scombriformes. It is found in temperate and tropical waters across the globe in the epipelagic and mesopelagic zones. There are six distinct stocks known globally in the Atlantic, Pacific, and Indian oceans, as well as the Mediterranean Sea. The albacore has an elongate, fusiform body with a conical snout, large eyes, and remarkably long pectoral fins. Its body is a deep blue dorsally and shades of silvery white ventrally. Individuals can reach up to 1.4 m in length.
Overfishing is the removal of a species of fish from a body of water at a rate greater than that the species can replenish its population naturally, resulting in the species becoming increasingly underpopulated in that area. Overfishing can occur in water bodies of any sizes, such as ponds, wetlands, rivers, lakes or oceans, and can result in resource depletion, reduced biological growth rates and low biomass levels. Sustained overfishing can lead to critical depensation, where the fish population is no longer able to sustain itself. Some forms of overfishing, such as the overfishing of sharks, has led to the upset of entire marine ecosystems. Types of overfishing include growth overfishing, recruitment overfishing, and ecosystem overfishing.
The Atlantic bluefin tuna is a species of tuna in the family Scombridae. It is variously known as the northern bluefin tuna, giant bluefin tuna [for individuals exceeding 150 kg (330 lb), and formerly as the tunny.
The yellowfin tuna is a species of tuna found in pelagic waters of tropical and subtropical oceans worldwide.
The spiny dogfish, spurdog, mud shark, or piked dogfish is one of the best known species of the Squalidae (dogfish) family of sharks, which is part of the Squaliformes order.
The white marlin, also known as Atlantic white marlin, marlin, skilligalee, is a species of billfish that lives in the epipelagic zone of the tropical and subtropical Atlantic Ocean. They are found between the latitudes of 45° N and 45° S in waters deeper than 100 m. Even though white marlin are found in bodies of water that are deeper than 100 m they tend to stay near the surface. White marlin have been found near banks, shoals, and canyons, but they are not limited to those locations. They prefer warm surface temperatures greater than 22 °C.
The Atlantic blue marlin is a species of marlin endemic to the Atlantic Ocean. It is closely related to, and usually considered conspecific with, the Indo-Pacific blue marlin, then simply called blue marlin. Some authorities consider both species distinct.
The billfish are a group of saltwater predatory fish characterised by prominent pointed bills (rostra), and by their large size; some are longer than 4 m (13 ft). Extant billfish include sailfish and marlin, which make up the family Istiophoridae; and swordfish, sole member of the family Xiphiidae. They are often apex predators which feed on a wide variety of smaller fish, crustaceans and cephalopods. These two families are sometimes classified as belonging to the order Istiophoriformes, a group which originated around 71 million years ago in the Late Cretaceous, with the two families diverging around 15 million years ago in the Late Miocene. However, they are also classified as being closely related to the mackerels and tuna within the suborder Scombroidei of the order Perciformes. However, the 5th edition of the Fishes of the World does recognise the Istiophoriformes as a valid order, albeit including the Sphyraenidae, the barracudas.
Pelagic fish live in the pelagic zone of ocean or lake waters—being neither close to the bottom nor near the shore—in contrast with demersal fish that live on or near the bottom, and reef fish that are associated with coral reefs.
The bigeye tuna is a species of true tuna of the genus Thunnus, belonging to the wider mackerel family Scombridae. In Hawaiian, it is one of two species known as ʻahi, the other being the yellowfin tuna. Bigeye tuna are found in the open waters of all tropical and temperate oceans, but not in the Mediterranean Sea.
Marlin fishing or billfishing is offshore saltwater game fishing targeting several species of fast-swimming pelagic predatory fish with elongated rostrum collectively known as billfish, which include those from the families Istiophoridae and Xiphiidae (swordfish). It is considered by some fishermen to be a pinnacle of big-game fishing, due to the size, speed and power of the billfish and their relative elusiveness.
The shortbill spearfish, sometimes called the short-nosed spearfish, is a species of marlin native to the Indian and Pacific Oceans, with occasional records from the Atlantic Ocean. This species occurs in open waters not far from the surface. This species can reach a length of 230 cm (91 in), though most do not exceed 190 cm (75 in). The maximum recorded weight for this species is 52 kg (115 lb). It is of minor importance to commercial fisheries and is also a game fish. Short bill spearfish are characterized by a slim frame with a blue body that is silver underneath. Shortbill also possess a very short bill extending from their upper jaw.
The roundscale spearfish is an Istiophoridae species of marlin living in the epipelagic zone of the Atlantic Ocean. It has long been misidentified as white marlin but can be differentiated thanks to their scale shapes that gives its name. Not much is known about this species. It could reach a length of 160 cm and 21,5 kg and has no conservation status yet due to a lack of data.
The Pacific bluefin tuna is a predatory species of tuna found widely in the northern Pacific Ocean, but it is migratory and also recorded as a visitor to the south Pacific.
Sustainable seafood is seafood that is caught or farmed in ways that consider the long-term vitality of harvested species and the well-being of the oceans, as well as the livelihoods of fisheries-dependent communities. It was first promoted through the sustainable seafood movement which began in the 1990s. This operation highlights overfishing and environmentally destructive fishing methods. Through a number of initiatives, the movement has increased awareness and raised concerns over the way our seafood is obtained.
As with other countries, the 200 nautical miles (370 km) exclusive economic zone (EEZ) off the coast of the United States gives its fishing industry special fishing rights. It covers 11.4 million square kilometres, which is the second largest zone in the world, exceeding the land area of the United States.
The following outline is provided as an overview of and topical guide to fisheries:
Of the twelve species of billfish, there are six species of Billfish in the Indian Ocean.