Fish migration information

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Fish migration information

Many types of fish migrate regularly on time scales from a day to or longer, and at distances ranging from a few meters to thousands of kilometers, and fish usually migrate to obtain food or to reproduce, but in other cases the reasons are not clear and this appeared after pollution environment and overfishing.

fish migration

The processes of migration and movement of fish from one part of a watery place to another are ensured on a regular basis, but the types of migration are irregular as the adult fish live in salt water and migrate to fresh water to breed or lay eggs. Forage fish make large migrations between spawning areas, feeding areas and fish incubation areas. Fish movements are linked to ocean currents and food availability in different areas and at different times of the year.

Migration movements may be partly related to the fact that fish cannot determine their offspring and move in this way to prevent fishing, and the United Nations Convention on the Law of the Sea has described some species of fish as the most migratory because of this reason, and these are the large pelagic fish that enter and leave the economic zones of countries different.

Salmon, striped bass and eel are among the most migratory fish. Bull shark migrates from fresh water to salt water as needed, and many marine fish perform vertical migration where fish rise to the surface to get their food and then return to the lower layers of the ocean. Day after day, some fish, such as tuna, travel from the north and south at different times of the year, following temperature gradients.

Fish migration patterns are of great importance in fishing operations, and movements of freshwater fish may also occur; The fish often swim toward the slope to unload the eggs, and these traditional movements are increasingly disrupted by the construction of dams.

Classification of fish migration

Zoologists have developed empirical classifications of fish migration and two special periods have long been in widespread use:

Slow fish, such as salmon, bass, and lamprey, migrate from the sea to fresh water to spawn eggs.

Sleeping fish migrate from fresh water down to salt water to unload eggs such as eels.

All fish migrate from salt water to fresh water.

Although these movements originated in fish, they apply to any aquatic organism.

forage fish

Forage fish often make large migrations between breeding grounds or spawning, feeding and incubating areas. For example, some herrings have spawning grounds in southern Norway, feeding grounds in Iceland, and nursery grounds in northern Norway. Triple trips like this may be important because forage fish.

The capelin fish is a forage fish of the smelt family found in the Atlantic and the Arctic Oceans. In the summer, they want to migrate and move to the shore in large swarms to eat crustaceans. It moves in the spring to unload the eggs and migrations are affected by ocean currents, and the fish returns to its homeland in the period from September to November, To begin another migration in December or January.

migratory fish up to

These species are considered highly migratory, such as types of tuna, albacore or albacore tuna, bluefin tuna, bigeye tuna, skipjack tuna, dolphins, swordfish, sharks and ocean fish, and these species with high levels of nutrition are based on long-distance travel over geographical distributions These species are found within the 200-mile economic zones of the high seas. They are pelagic species that live mostly in the open ocean and do not live near the sea floor, although they may spend part of their life cycle in inshore waters.

Examples of migratory fish

Some of the most well-known fish species are Pacific salmon, such as chinook (king), coho (silver), chum (dog), pink and red salmon, and sockeye. These fish hatch in small fresh water streams, then migrate to salt water to live from two to six years. At maturity, salmon return for the same journey until the eggs are empty, and the fish are able to leave hundreds of kilometers.

Since the dawn of history, man has exploited freshwater fish migrations for fishing, but overfishing in the seasons of fish migration to unload eggs led to the extinction of large species and breeds of fish, and today there are many laws that protect marine life and prevent fishing at the time of migration..

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