Herring and their relatives are among the most important of commercial ﬁsh worldwide. They are also extremely important as forage ﬁsh for a wide variety of predatory ﬁsh, sea birds, seals, and other carnivores. In the past, some countries depended entirely on the herring (or related species) ﬁshery for their economic survival. Wars have been waged over the rights to particularly productive herring grounds, which are found in all seas except the very cold waters of the Arctic and the Antarctic.
Most members of the herring family are strictly marine. Some are anadromous and spawn in freshwater, and a few species (those of freshwater origin) never go to sea. Herring typically travel in extensive schools; in the ocean, such schools may extend for miles, which makes harvesting possible in great quantities.
Herring are plankton feeders, screening their food through numerous gill rakers. As such, and because they are generally small, herring are seldom a deliberate quarry of recreational anglers (American and hickory shad are notable exceptions). They are primarily used as bait, either in pieces or whole, by freshwater and saltwater anglers for various game species.
Prominent species with the herring name include Atlantic herring, Paciﬁc herring, blueback herring, and skipjack herring. At least two members of the herring family, the alewife and the blueback herring, are collectively referred to as river herring.
There is minor angling effort for some species, such as blueback and skipjack herring, when they ascend coastal rivers en masse to spawn; this ﬁshery is generally geared more toward procuring food or bait than to pure angling sport. They may, however, be caught on light spoons and small jigs or ﬂies. When massed, they are also taken by snagging (where legal) and in cast nets. Coastal herring are sometimes caught, snagged, or taken by a cast net, mainly for use as bait.