Atlantic cod
Encyclopedia
The Atlantic cod, Gadus morhua, is a well-known demersal food fish
belonging to the family Gadidae
. It is also commercially
known as cod
, codling or haberdine.
In the western Atlantic Ocean
cod
has a distribution north of Cape Hatteras
, North Carolina
, and round both coasts of Greenland
; in the eastern Atlantic it is found from the Bay of Biscay
north to the Arctic Ocean
, including the Baltic Sea
, the North Sea
, Sea of the Hebrides
, areas around Iceland
and the Barents Sea
.
It can grow to 2 meters in length and weigh up to 96 kilograms (211.6 lb). It can live for 25 years and sexual maturity is generally attained between ages 2 to 4, but can be as late as 8 years in the northeast Arctic. Colouring is brown to green with spots on the dorsal
side, shading to silver ventrally. A lateral line is clearly visible. Its habitat
ranges from the shoreline down to the continental shelf
.
Several cod stocks collapsed in the 1990s (declined by >95% of maximum historical biomass
) and have failed to recover even with the cessation of fishing. This absence of the apex predator
has led to a trophic cascade
in many areas. Many other cod stocks remain at risk. The "Atlantic Cod" is labelled VU (vulnerable) on the IUCN Red List of Threatened Species.
The Northeast Atlantic is the world's largest population of cod. By far the largest part of this population is the North-East Arctic Cod, as it is labelled by the ICES
, or the Arcto-Norwegian cod stock, also referred to as skrei, a Norwegian name meaning something like "the wanderer", distinguishing it from coastal cod. The North-East Arctic Cod is found in the Barents Sea
area. This stock spawns in March and April along the Norwegian coast, about 40% around the Lofoten
archipelago
. Newly hatched larvae drift northwards with the coastal current while feeding on larval copepod
s. By summer the young cod reach the Barents Sea where they stay for the rest of their life, until their spawning migration. As the cod grow, they feed on krill
and other small crustacean
s and fish. Adult cod primarily feed on fish such as capelin
and herring
. The northeast Arctic cod also shows cannibalistic
behaviour. Estimated stock size was in 2008 2.26 million tonnes.
The North Sea cod stock is primarily fished by European Union
member states and Norway. In 1999 the catch was divided among Denmark (31%), Scotland (25%), the rest of the United Kingdom
(12%), the Netherlands
(10%), Belgium
, Germany
and Norway
(17%). In the 1970s, the annual catch rose to between 200,000 - 300,000 tons. Due to concerns about overfishing, catch quotas were repeatedly reduced in the 1980s and 1990s. In 2003, ICES
stated that there is a high risk of stock collapse if current exploitation levels continue, and recommended a moratorium on catching Atlantic cod in the North Sea
during 2004. However, agriculture and fisheries ministers from the Council of the European Union
endorsed the EU/Norway Agreement and set the total allowable catch (TAC) 27,300 tons. Seafood sustainability guides such as the Monterey Bay Aquarium's
Seafood Watch
often recommend environmentally conscious customers not purchase Atlantic Cod.
, but declined to a historic minimum of 118,000 tons in 1987. The North-East Arctic cod catch reached a historic maximum of 1,343,000 tons in 1956, and bottomed out at 212,000 tons in 1990. Since 2000, the spawning stock has increased quite quickly, helped by low fishing pressure. However, there are worries about a decreased age at first spawning (often an early sign of stock collapse), combined with the level of discards and unreported catches. The total catch in 2003 was 521,949 tons, the major fishers being Norway
(191,976 tons) and Russia
(182,160 tons).
The northwest Atlantic cod has been regarded as heavily overfished throughout its range, resulting in a crash in the fishery
in the United States
and Canada
during the early 1990s.
Newfoundland's northern cod fishery can be traced back to the 16th century. "On average, about 300,000 tonnes of cod was landed annually until the 1960s, when advances in technology enabled factory trawlers to take larger catches. By 1968, landings for the fish peaked at 800,000 tonnes before a gradual decline set in. With the reopening of the limited cod fisheries in 2006, nearly 2,700 tonnes of cod were hauled in. In 2007, it was estimated that offshore cod stocks were at one per cent of what they were in 1977".
Technologies that contributed to the collapse of Atlantic Cod include engine power vessels and frozen food compartments aboard ships. Engine power vessels had larger nets, larger engines, and better navigation. The capacity to catch fish became limitless. In addition, sonar technology gave an edge to catching and detecting fish. Sonar was originally developed during WWII to locate enemy submarines, but was later applied to locating schools of fish. These new technologies, as well as bottom-trawlers that destroyed entire ecosystems, contributed to the collapse of Atlantic Cod. They were vastly different from old techniques used, such as hand lines and long lines.
The fishery has yet to recover, and may not recover at all because of a possibly stable change in the food chain
. Atlantic cod was a top-tier predator, along with haddock
, flounder
and hake
, feeding upon smaller prey such as herring
, capelin
, shrimp
and snow crab. With the large predatory fish removed, their prey has had a population explosion and have become the top predators, affecting the survival rates of cod eggs and fry.
Cod populations or stocks can differ significantly both in appearance and biology. For instance, the cod stocks of the Baltic Sea
are adapted to low-salinity water. Organisations such as the Northwest Atlantic Fishery Organization (NAFO) and ICES
divide the cod into management units or stocks; however these units are not always biologically distinguishable stocks. Some major stocks/management units on the Canadian/US shelf (see map of NAFO areas) are the Southern Labrador-Eastern Newfoundland stock (NAFO divisions 2J3KL), the Northern Gulf of St. Lawrence stock (NAFO divisions 3Pn4RS), the Northern Scotian Shelf stock (NAFO divisions 4VsW), which all lie in Canadian waters, and the Georges Bank and Gulf of Maine
stocks in United States waters. In the European Atlantic, there are numerous separate stocks: on the shelves of Iceland, the coast of Norway, the Barents Sea, the Faroe Islands, off western Scotland, the North Sea, the Irish Sea, the Celtic Sea
and in the Baltic Sea.
Females release their eggs in batches, and males compete to fertilise them.
Cod can live for 13 years or more.
Monogenea
Trematoda
- metacerkariae
Trematoda - adult
Cestoda
- larval forms
Cestoda
- adult
Nematoda - larval forms
Nematoda - adults
Acanthocephala
- post-cystacanths
Acanthocephala - adults
Hirudinea - adults
Copepoda - larval forms
Copepoda - adults
Amphipoda
Isopoda
Seafood
Seafood is any form of marine life regarded as food by humans. Seafoods include fish, molluscs , crustaceans , echinoderms . Edible sea plants, such as some seaweeds and microalgae, are also seafood, and are widely eaten around the world, especially in Asia...
belonging to the family Gadidae
Gadidae
Gadidae is a family of marine fish, included in the order Gadiformes. It includes the cod, haddock, whiting, and pollock.Most species of gadid are found in temperate waters of the northern hemisphere, although there are some exceptions. They are generally medium sized fish, and are distinguished...
. It is also commercially
Commercial fishing
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions...
known as cod
Cod
Cod is the common name for genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
, codling or haberdine.
In the western Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
cod
Cod
Cod is the common name for genus Gadus, belonging to the family Gadidae, and is also used in the common name for various other fishes. Cod is a popular food with a mild flavor, low fat content and a dense, flaky white flesh. Cod livers are processed to make cod liver oil, an important source of...
has a distribution north of Cape Hatteras
Cape Hatteras
Cape Hatteras is a cape on the coast of North Carolina. It is the point that protrudes the farthest to the southeast along the northeast-to-southwest line of the Atlantic coast of North America...
, North Carolina
North Carolina
North Carolina is a state located in the southeastern United States. The state borders South Carolina and Georgia to the south, Tennessee to the west and Virginia to the north. North Carolina contains 100 counties. Its capital is Raleigh, and its largest city is Charlotte...
, and round both coasts of Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
; in the eastern Atlantic it is found from the Bay of Biscay
Bay of Biscay
The Bay of Biscay is a gulf of the northeast Atlantic Ocean located south of the Celtic Sea. It lies along the western coast of France from Brest south to the Spanish border, and the northern coast of Spain west to Cape Ortegal, and is named in English after the province of Biscay, in the Spanish...
north to the Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
, including the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...
, the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
, Sea of the Hebrides
Sea of the Hebrides
The Sea of the Hebrides is a portion of the North Atlantic Ocean, located off the coast of western Scotland, separating the mainland and the northern Inner Hebrides islands from the southern Outer Hebrides islands...
, areas around Iceland
Iceland
Iceland , described as the Republic of Iceland, is a Nordic and European island country in the North Atlantic Ocean, on the Mid-Atlantic Ridge. Iceland also refers to the main island of the country, which contains almost all the population and almost all the land area. The country has a population...
and the Barents Sea
Barents Sea
The Barents Sea is a marginal sea of the Arctic Ocean, located north of Norway and Russia. Known in the Middle Ages as the Murman Sea, the sea takes its current name from the Dutch navigator Willem Barents...
.
It can grow to 2 meters in length and weigh up to 96 kilograms (211.6 lb). It can live for 25 years and sexual maturity is generally attained between ages 2 to 4, but can be as late as 8 years in the northeast Arctic. Colouring is brown to green with spots on the dorsal
Dorsum (biology)
In anatomy, the dorsum is the upper side of animals that typically run, fly, or swim in a horizontal position, and the back side of animals that walk upright. In vertebrates the dorsum contains the backbone. The term dorsal refers to anatomical structures that are either situated toward or grow...
side, shading to silver ventrally. A lateral line is clearly visible. Its habitat
Habitat (ecology)
A habitat is an ecological or environmental area that is inhabited by a particular species of animal, plant or other type of organism...
ranges from the shoreline down to the continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...
.
Several cod stocks collapsed in the 1990s (declined by >95% of maximum historical biomass
Biomass
Biomass, as a renewable energy source, is biological material from living, or recently living organisms. As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel....
) and have failed to recover even with the cessation of fishing. This absence of the apex predator
Apex predator
Apex predators are predators that have no predators of their own, residing at the top of their food chain. Zoologists define predation as the killing and consumption of another organism...
has led to a trophic cascade
Trophic cascade
Trophic cascades occur when predators in a food web suppress the abundance of their prey, thereby releasing the next lower trophic level from predation...
in many areas. Many other cod stocks remain at risk. The "Atlantic Cod" is labelled VU (vulnerable) on the IUCN Red List of Threatened Species.
Northeast Atlantic cod
Ices
Ices may refer to:*Frozen desserts, particularly within the United Kingdom*Frozen volatiles, in the context of astronomy and planetary science*Phases of iceICES may stand for:*Inflight Crew Escape System, in the Space Shuttle...
, or the Arcto-Norwegian cod stock, also referred to as skrei, a Norwegian name meaning something like "the wanderer", distinguishing it from coastal cod. The North-East Arctic Cod is found in the Barents Sea
Barents Sea
The Barents Sea is a marginal sea of the Arctic Ocean, located north of Norway and Russia. Known in the Middle Ages as the Murman Sea, the sea takes its current name from the Dutch navigator Willem Barents...
area. This stock spawns in March and April along the Norwegian coast, about 40% around the Lofoten
Lofoten
Lofoten is an archipelago and a traditional district in the county of Nordland, Norway. Though lying within the Arctic Circle, the archipelago experiences one of the world's largest elevated temperature anomalies relative to its high latitude.-Etymology:...
archipelago
Archipelago
An archipelago , sometimes called an island group, is a chain or cluster of islands. The word archipelago is derived from the Greek ἄρχι- – arkhi- and πέλαγος – pélagos through the Italian arcipelago...
. Newly hatched larvae drift northwards with the coastal current while feeding on larval copepod
Copepod
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...
s. By summer the young cod reach the Barents Sea where they stay for the rest of their life, until their spawning migration. As the cod grow, they feed on krill
Krill
Krill is the common name given to the order Euphausiacea of shrimp-like marine crustaceans. Also known as euphausiids, these small invertebrates are found in all oceans of the world...
and other small crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s and fish. Adult cod primarily feed on fish such as capelin
Capelin
The capelin or caplin, Mallotus villosus, is a small forage fish of the smelt family found in the Atlantic and Arctic oceans. In summer, it grazes on dense swarms of plankton at the edge of the ice shelf. Larger capelin also eat a great deal of krill and other crustaceans...
and herring
Atlantic herring
Atlantic herring is a fish in the family Clupeidae. It is one of the most abundant fish species on earth. Herring can be found on both sides of the Atlantic Ocean, congregating in large schools. They can grow up to in length and weigh more than...
. The northeast Arctic cod also shows cannibalistic
Cannibalism (zoology)
In zoology, cannibalism is the act of one individual of a species consuming all or part of another individual of the same species as food. Cannibalism is a common ecological interaction in the animal kingdom and has been recorded for more than 1500 species...
behaviour. Estimated stock size was in 2008 2.26 million tonnes.
The North Sea cod stock is primarily fished by European Union
European Union
The European Union is an economic and political union of 27 independent member states which are located primarily in Europe. The EU traces its origins from the European Coal and Steel Community and the European Economic Community , formed by six countries in 1958...
member states and Norway. In 1999 the catch was divided among Denmark (31%), Scotland (25%), the rest of the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
(12%), the Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
(10%), Belgium
Belgium
Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
and Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
(17%). In the 1970s, the annual catch rose to between 200,000 - 300,000 tons. Due to concerns about overfishing, catch quotas were repeatedly reduced in the 1980s and 1990s. In 2003, ICES
International Council for the Exploration of the Sea
The International Council for the Exploration of the Sea is the world’s oldest intergovernmental science organization. ICES is headquartered in Copenhagen, Denmark, where its multinational Secretariat staff of 51 provide scientific, administrative and secretarial support to the ICES community...
stated that there is a high risk of stock collapse if current exploitation levels continue, and recommended a moratorium on catching Atlantic cod in the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...
during 2004. However, agriculture and fisheries ministers from the Council of the European Union
Council of the European Union
The Council of the European Union is the institution in the legislature of the European Union representing the executives of member states, the other legislative body being the European Parliament. The Council is composed of twenty-seven national ministers...
endorsed the EU/Norway Agreement and set the total allowable catch (TAC) 27,300 tons. Seafood sustainability guides such as the Monterey Bay Aquarium's
Monterey Bay Aquarium
The Monterey Bay Aquarium is located on the former site of a sardine cannery on Cannery Row of the Pacific Ocean shoreline in Monterey, California. It has an annual attendance of 1.8 million visitors. It holds thousands of plants and animals, representing 623 separate named species on display...
Seafood Watch
Seafood Watch
Seafood Watch is one of the best known sustainable seafood advisory lists, and has influenced similar programs around the world. It is a program designed to raise consumer awareness about the importance of buying seafood from sustainable sources...
often recommend environmentally conscious customers not purchase Atlantic Cod.
Spawning
The stock of North-East Arctic cod was more than a million tons following World War IIWorld War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, but declined to a historic minimum of 118,000 tons in 1987. The North-East Arctic cod catch reached a historic maximum of 1,343,000 tons in 1956, and bottomed out at 212,000 tons in 1990. Since 2000, the spawning stock has increased quite quickly, helped by low fishing pressure. However, there are worries about a decreased age at first spawning (often an early sign of stock collapse), combined with the level of discards and unreported catches. The total catch in 2003 was 521,949 tons, the major fishers being Norway
Norway
Norway , officially the Kingdom of Norway, is a Nordic unitary constitutional monarchy whose territory comprises the western portion of the Scandinavian Peninsula, Jan Mayen, and the Arctic archipelago of Svalbard and Bouvet Island. Norway has a total area of and a population of about 4.9 million...
(191,976 tons) and Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
(182,160 tons).
Northwest Atlantic cod
Fishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
and Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
during the early 1990s.
Newfoundland's northern cod fishery can be traced back to the 16th century. "On average, about 300,000 tonnes of cod was landed annually until the 1960s, when advances in technology enabled factory trawlers to take larger catches. By 1968, landings for the fish peaked at 800,000 tonnes before a gradual decline set in. With the reopening of the limited cod fisheries in 2006, nearly 2,700 tonnes of cod were hauled in. In 2007, it was estimated that offshore cod stocks were at one per cent of what they were in 1977".
Technologies that contributed to the collapse of Atlantic Cod include engine power vessels and frozen food compartments aboard ships. Engine power vessels had larger nets, larger engines, and better navigation. The capacity to catch fish became limitless. In addition, sonar technology gave an edge to catching and detecting fish. Sonar was originally developed during WWII to locate enemy submarines, but was later applied to locating schools of fish. These new technologies, as well as bottom-trawlers that destroyed entire ecosystems, contributed to the collapse of Atlantic Cod. They were vastly different from old techniques used, such as hand lines and long lines.
The fishery has yet to recover, and may not recover at all because of a possibly stable change in the food chain
Food chain
A food web depicts feeding connections in an ecological community. Ecologists can broadly lump all life forms into one of two categories called trophic levels: 1) the autotrophs, and 2) the heterotrophs...
. Atlantic cod was a top-tier predator, along with haddock
Haddock
The haddock , also known as the offshore hake, is a marine fish distributed on both sides of the North Atlantic. Haddock is a popular food fish and is widely fished commercially....
, flounder
Flounder
The flounder is an ocean-dwelling flatfish species that is found in coastal lagoons and estuaries of the Northern Atlantic and Pacific Oceans.-Taxonomy:There are a number of geographical and taxonomical species to which flounder belong.*Western Atlantic...
and hake
Hake
The term hake refers to fish in either of:* family Phycidae of the northern oceans* family Merlucciidae of the southern oceans-Hake fish:...
, feeding upon smaller prey such as herring
Herring
Herring is an oily fish of the genus Clupea, found in the shallow, temperate waters of the North Pacific and the North Atlantic oceans, including the Baltic Sea. Three species of Clupea are recognized. The main taxa, the Atlantic herring and the Pacific herring may each be divided into subspecies...
, capelin
Capelin
The capelin or caplin, Mallotus villosus, is a small forage fish of the smelt family found in the Atlantic and Arctic oceans. In summer, it grazes on dense swarms of plankton at the edge of the ice shelf. Larger capelin also eat a great deal of krill and other crustaceans...
, shrimp
Shrimp
Shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. Adult shrimp are filter feeding benthic animals living close to the bottom. They can live in schools and can swim rapidly backwards. Shrimp are an important...
and snow crab. With the large predatory fish removed, their prey has had a population explosion and have become the top predators, affecting the survival rates of cod eggs and fry.
Population tracking
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...
are adapted to low-salinity water. Organisations such as the Northwest Atlantic Fishery Organization (NAFO) and ICES
International Council for the Exploration of the Sea
The International Council for the Exploration of the Sea is the world’s oldest intergovernmental science organization. ICES is headquartered in Copenhagen, Denmark, where its multinational Secretariat staff of 51 provide scientific, administrative and secretarial support to the ICES community...
divide the cod into management units or stocks; however these units are not always biologically distinguishable stocks. Some major stocks/management units on the Canadian/US shelf (see map of NAFO areas) are the Southern Labrador-Eastern Newfoundland stock (NAFO divisions 2J3KL), the Northern Gulf of St. Lawrence stock (NAFO divisions 3Pn4RS), the Northern Scotian Shelf stock (NAFO divisions 4VsW), which all lie in Canadian waters, and the Georges Bank and Gulf of Maine
Gulf of Maine
The Gulf of Maine is a large gulf of the Atlantic Ocean on the east coast of North America.It is delineated by Cape Cod at the eastern tip of Massachusetts in the southwest and Cape Sable at the southern tip of Nova Scotia in the northeast. It includes the entire coastlines of the U.S...
stocks in United States waters. In the European Atlantic, there are numerous separate stocks: on the shelves of Iceland, the coast of Norway, the Barents Sea, the Faroe Islands, off western Scotland, the North Sea, the Irish Sea, the Celtic Sea
Celtic Sea
The Celtic Sea is the area of the Atlantic Ocean off the south coast of Ireland bounded to the east by Saint George's Channel; other limits include the Bristol Channel, the English Channel, and the Bay of Biscay, as well as adjacent portions of Wales, Cornwall, Devon, and Brittany...
and in the Baltic Sea.
Spawning
Adult cod form spawning aggregations from late winter to spring.Females release their eggs in batches, and males compete to fertilise them.
Adults
Age of maturation varies between cod stocks, from ages 2 to 4 in the west Atlantic, but as late as 8 years in the northeast Arctic.Cod can live for 13 years or more.
Anatomy
Parasites
Atlantic cod act as intermediate, paratenic or definitive hosts to a large number of parasite species: 107 taxa listed by Hemmingsen and MacKenzie (2001) and sevev new records by Perdiguero-Alonso et al. (2008). The predominant groups of cod parasites in the northeast Atlantic were trematodes (19 species) and nematodes (13 species), including larval anisakids, which comprised 58.2% of the total number of individuals. Parasites of Atlantic cod include copepods, digeneans, monogeneans, acanthocephalans, cestodes, nematodes, myxozoans and protozoans:Monogenea
Monogenea
Monogenea are a group of largely ectoparasitic members of the flatworm phylum Platyhelminthes, class Monogenea.-Characteristics:Monogenea are very small parasitic flatworms mainly found on skin or gills of fish....
- Diclidophora merlangi
Trematoda
Trematoda
Trematoda is a class within the phylum Platyhelminthes that contains two groups of parasitic flatworms, commonly referred to as "flukes".-Taxonomy and biodiversity:...
- metacerkariae
- Bucephalinae gen. sp.
- Cryptocotyle lingua
- Otodistomum sp.
- Prosorynchoides gracilescens
- Prosorhynchus crucibulum
- Rhipidocotyle sp.
Trematoda - adult
- Derogenes varicus
- Fellodistomum sp.
- Gonocerca phycidis
- Hemiurus communis
- Hemiurus levinseni
- Hemiurus luehei
- Lecithaster sp. ?gibbosus
- Lepidapedon elongatum
- Lepidapedon rachion
- Opechona bacillaris
- Podocotyle reflexa
- Stephanostomum spp.
- Steringotrema sp.
Cestoda
Cestoda
This article describes the flatworm. For the medical condition, see Tapeworm infection.Cestoda is the name given to a class of parasitic flatworms, commonly called tapeworms, of the phylum Platyhelminthes. Its members live in the digestive tract of vertebrates as adults, and often in the bodies...
- larval forms
- Grillotia sp.
- Hepatoxylon sp.
- Lacistorhynchus sp.
- Scolex pleuronectis
- PseudophyllideaPseudophyllideaPseudophyllid cestodes are a kind of flatworm with multiple "segments" and two bothria or "sucking grooves" as adults...
fam. gen. sp. - Schistocephalus gasterostei
- TrypanorhynchaTrypanorhynchaTrypanorhyncha is an order of cestode, a type of Flatworm.Some species infect gamefish, such as sciaenids, during the parasitic worm's plerocercoid stage, and are commonly called spaghetti worm because of their appearance, approximating cooked spaghetti. Such species include Poecilancistrium...
fam. gen. sp. - Unidentified plerocercoidPlerocercoidPlerocercoid refers to last larval form found in the second intermediate host of many Cestoda with aquatic life cycles....
s
Cestoda
Cestoda
This article describes the flatworm. For the medical condition, see Tapeworm infection.Cestoda is the name given to a class of parasitic flatworms, commonly called tapeworms, of the phylum Platyhelminthes. Its members live in the digestive tract of vertebrates as adults, and often in the bodies...
- adult
- Abothrium gadi
Nematoda - larval forms
- Anisakis simplex (s.l.)
- Contracaecum osculatum (s.l.)
- Hysterothylacium aduncum
- Hysterothylacium rigidum
- Pseudoterranova decipiens (s.l.)
- Rhapidascaris sp.
Nematoda - adults
- Ascarophis morrhuae
- Ascarophis crassicollis
- Ascarophis filiformis
- Capillaria gracilis
- Cucullanus cirratus
- Cucullanus sp.
- Hysterothylacium aduncum
- Spinitectus sp.
Acanthocephala
Acanthocephala
Acanthocephala is a phylum of parasitic worms known as acanthocephales, thorny-headed worms, or spiny-headed worms, characterized by the presence of an evertable proboscis, armed with spines, which it uses to pierce and hold the gut wall of its host...
- post-cystacanths
- Corynosoma semerme
- Corynosoma strumosum
Acanthocephala - adults
- Echinorhynchus gadi (s.l.)
Hirudinea - adults
- Calliobdella nodulifera
- Johanssonia arctica
Copepoda - larval forms
- CaligusCaligusCaligus is a genus of sea lice in the family Caligidae. The species are parasites of marine fishes and could be vectors of viruses....
sp. copepodite - Copepoda fam. gen. sp. copepodite
Copepoda - adults
- Acanthochondria soleae
- Caligus curtusCaligus curtusCaligus curtus is a sea louse species and a parasite of the Atlantic cod....
- Caligus diaphanus
- Caligus elongatus
- Chondracanthus ornatus
- Clavella adunca
- Holobomolochus confusus
- Lernaeocera branchialisLernaeocera branchialisLernaeocera branchialis, sometimes called cod worm, is a parasite of marine fish, found mainly in the North Atlantic. It is a marine copepod which starts life as a small pelagic crustacean larvae...
Amphipoda
Amphipoda
Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. The name amphipoda means "different-footed", and refers to the different forms of appendages, unlike isopods, where all the legs are alike. Of the 7,000 species, 5,500 are classified...
- Lafystius sturionis
Isopoda
Isopoda
Isopods are an order of peracarid crustaceans, including familiar animals such as woodlice and pill bugs. The name Isopoda derives from the Greek roots and...
- Gnathia elongata (praniza larva)
External links
- FishBase
- Codtrace
- The Centre for Environment Fisheries and Aquaculture Science
- The history of the northern cod fishery in Canada
- ICES recommendation for the North Sea Cod stock (2007)
- ICES recommendation for the North East Arctic Cod stock (2007)
- Reports on the status of Canadian fishing stocks, including cod
- Governmental Norwegian fact sheet on North-East Arctic Cod