Wide triangular journeys such as these may be important because forage fish, when feeding, cannot distinguish their own offspring.
Capelin are a forage fish of the smelt family found in the Atlantic and Arctic oceans.
The patterns of migration are of great interest to the fishing industry.
Movements of fish in fresh water also occur; often the fish swim upriver to spawn, and these traditional movements are increasingly being disrupted by the building of dams. Myers coined the inclusive term diadromous to refer to all fishes that migrate between the sea and fresh water.
In a paper published in 2009, researchers from Iceland recount their application of an interacting particle model to the capelin stock around Iceland, successfully predicting the spawning migration route for 2008.
The term highly migratory species (HMS) has its origins in Article 64 of the United Nations Convention on the Law of the Sea (UNCLOS).
The Convention does not provide an operational definition of the term, but in an annex (UNCLOS Annex 1) lists the species considered highly migratory by parties to the Convention.
Like the two well known terms, it was formed from classical Greek ([dia], "through"; and [dromous], "running").
Diadromous proved a useful word, but terms proposed by Myers for other types of diadromous fishes did not catch on.
Thus, these species are found both inside the 200 mile exclusive economic zones and in the high seas outside these zones.