The migratory movements may partly be linked to the fact that the fish cannot identify their own offspring and moving in this way prevents cannibalism. Movements are associated with ocean currents and with the availability of food in different areas at different times of year. Marine forage fish often make large migrations between their spawning, feeding and nursery grounds. Some particular types of migration are anadromous, in which adult fish live in the sea and migrate into fresh water to spawn and catadromous, in which adult fish live in fresh water and migrate into salt water to spawn. Such migrations are usually done for better feeding or to reproduce, but in other cases the reasons are unclear.įish migrations involve movements of schools of fish on a scale and duration larger than those arising during normal daily activities. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres. Movement of fishes from one part of a water body to another on a regular basis Many species of salmon are anadromous and can migrate long distances up rivers to spawn Allowing fish and other migratory animals to travel the rivers can help maintain healthy fish populationsįish migration is mass relocation by fish from one area or body of water to another.
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