Herrings are exported to the annual value of ioo,000 to X200,000, also mackerel and lobsters.
Therefore mackerel generally swim in a straightforward direction, deviating sidewards only when compelled, and rarely turning about in the same spot.
All fishes of the mackerel family are strictly carnivorous; they unceasingly pursue their prey, which consists principally of other fish and pelagic crustaceans.
The fry of clupeoids, which likewise swim in schools, are followed by the mackerel until they reach some shallow place, which their enemies dare not enter.
In the 17th century the mackerel and whale fisheries were the basis of economic life; the latter gave way later to the cod and other fisheries, but the fishing industry is now relatively unimportant.
The whaling and cod and mackerel fisheries were of earlier colonial origin.
In some years between 1852 and 1867 the old mackerel disappeared off Guernsey from the surface, and were accidentally discovered feeding at the bottom.
The mackerel proper (genus Scomber) are readily recognized by their elegantly shaped, well-proportioned body, shining in iridescent colours.
Pilchard, herrings, whiting and mackerel are taken, and salmon in the Teign.
Although, on the whole, the course and time of the annual migration of mackerel are marked with great regularity, their appearance and abundance at certain localities are subject to great variations.