Herring

Herring, most commonly referring to the Atlantic herring, is the type species of the family Clupeidae and one of the most numerically abundant fish on Earth. It occurs across the cold-temperate North Atlantic, from the eastern seaboard of North America to the coasts of Europe, with a closely related Pacific counterpart, Clupea pallasii, occupying the North Pacific. Herring live in massive, highly synchronized schools that can number in the millions and play an outsized ecological role, transferring energy from plankton to a huge array of predators including cod, seabirds, seals, and whales. Their populations naturally fluctuate but the species remains widespread and abundant across its range.

Herring have a classic, unadorned silvery build shared across the clupeid family.

• Body: slender, elongate, and laterally compressed
• Color: iridescent blue-green to steel-blue back, bright silver flanks and belly, no dark spots
• Scales: large, thin, and easily dislodged, giving a shimmering appearance
• Fins: single soft dorsal fin roughly at the body's midpoint; deeply forked tail
• Belly: smooth, without the sharp saw-edged scutes seen in menhaden or shad
• Size: typically 20-38 cm The absence of spotting and the smooth, non-serrated belly help separate herring from sardines, menhaden, and shad, which usually show one or more marks or a sawtooth keel.

Herring inhabit cold-temperate continental shelf waters of the North Atlantic, ranging from Labrador and the Gulf of Maine to the North Sea, Baltic Sea, and Norwegian coast, typically at depths from the surface to around 200 meters. They are a pelagic, open-water species, spending most of their life in the water column rather than near the bottom, and undertake extensive seasonal migrations between offshore feeding grounds, spawning areas, and overwintering sites. Spawning occurs on specific gravel or shell-bottom banks in coastal and shelf waters, with distinct regional populations returning to traditional spawning grounds. Water temperature and plankton abundance strongly influence school distribution throughout the year.

Herring are famous for forming some of the largest fish schools in the ocean, with individuals coordinating movement using vision and their lateral line to maintain tight formation, a behavior that offers protection from predators. They feed on zooplankton, straining copepods and other small crustaceans from the water using fine gill rakers, often migrating vertically each day to follow plankton concentrations. Spawning is seasonal and highly synchronized, with adults gathering at traditional spawning banks to release eggs onto the seabed, where they stick to gravel or shell substrate until hatching. As one of the ocean's key forage fish, herring schools support ecological food webs, sustaining populations of larger fish, seabirds, and marine mammals throughout the North Atlantic.